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    <link:label id="lab_cik0001563922_GainLossOnDispositionOfOtherAssetsExcludingOtherImmaterialSales_label_en-US" xlink:label="lab_cik0001563922_GainLossOnDispositionOfOtherAssetsExcludingOtherImmaterialSales" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Disposition of Other Assets, Excluding Other Immaterial Sales</link:label>
    <link:label id="lab_cik0001563922_GainLossOnDispositionOfOtherAssetsExcludingOtherImmaterialSales_documentation_en-US" xlink:label="lab_cik0001563922_GainLossOnDispositionOfOtherAssetsExcludingOtherImmaterialSales" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Disposition of Other Assets, Excluding Other Immaterial Sales</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GainLossOnDispositionOfOtherAssetsExcludingOtherImmaterialSales" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GainLossOnDispositionOfOtherAssetsExcludingOtherImmaterialSales"/>
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    <link:label id="lab_cik0001563922_TwoCustomerMember_019f7115-c554-7906-a113-bca1af6e5c6b_terseLabel_en-US" xlink:label="lab_cik0001563922_TwoCustomerMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Two Customer</link:label>
    <link:label id="lab_cik0001563922_TwoCustomerMember_label_en-US" xlink:label="lab_cik0001563922_TwoCustomerMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Two Customer [Member]</link:label>
    <link:label id="lab_cik0001563922_TwoCustomerMember_documentation_en-US" xlink:label="lab_cik0001563922_TwoCustomerMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Two Customer</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TwoCustomerMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TwoCustomerMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_TwoCustomerMember" xlink:to="lab_cik0001563922_TwoCustomerMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerTextBlock_019f7115-c6fc-7260-bad4-86862ec7f8ee_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenue</link:label>
    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerTextBlock_label_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue from Contract with Customer [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:to="lab_us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVManagementShareUnitsMember_019f7115-c6fc-76b5-9639-5837fd8a07cb_terseLabel_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVManagementShareUnitsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GDEV Management Holdings LLC member interests</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVManagementShareUnitsMember_label_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVManagementShareUnitsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities Fund I, LP (GDEV) Management Share Units [Member]</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVManagementShareUnitsMember_documentation_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVManagementShareUnitsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities Fund I, LP (GDEV) Management Share Units</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVManagementShareUnitsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVManagementShareUnitsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVManagementShareUnitsMember" xlink:to="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVManagementShareUnitsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfStockByClassTable_019f7115-c6fc-7c65-9470-54ca92789d5b_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfStockByClassTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock, Class of Stock [Table]</link:label>
    <link:label id="lab_us-gaap_ScheduleOfStockByClassTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfStockByClassTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock, Class of Stock [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable" xlink:to="lab_us-gaap_ScheduleOfStockByClassTable" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassAxis_019f7115-c5e8-7c75-97b6-a52c86206623_terseLabel_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities By Major Class [Axis]</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassAxis_label_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities By Major Class [Axis]</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassAxis_documentation_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities By Major Class</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassAxis" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassAxis" xlink:to="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DistributionsMadeToLimitedLiabilityCompanyLLCMemberTable_019f7115-c554-70d0-b237-4ffd3cf655a5_terseLabel_en-US" xlink:label="lab_us-gaap_DistributionsMadeToLimitedLiabilityCompanyLLCMemberTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distributions Made to Limited Liability Company (LLC) Member [Table]</link:label>
    <link:label id="lab_us-gaap_DistributionsMadeToLimitedLiabilityCompanyLLCMemberTable_label_en-US" xlink:label="lab_us-gaap_DistributionsMadeToLimitedLiabilityCompanyLLCMemberTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distributions Made to Limited Liability Company (LLC) Member [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DistributionsMadeToLimitedLiabilityCompanyLLCMemberTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DistributionsMadeToLimitedLiabilityCompanyLLCMemberTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DistributionsMadeToLimitedLiabilityCompanyLLCMemberTable" xlink:to="lab_us-gaap_DistributionsMadeToLimitedLiabilityCompanyLLCMemberTable" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_EarnoutPeriodTrancheTwoMember_019f7115-c555-739a-ae67-6ca85b930be3_terseLabel_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodTrancheTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tranche 2 Earnout Shares</link:label>
    <link:label id="lab_cik0001563922_EarnoutPeriodTrancheTwoMember_label_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodTrancheTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Earnout Period, Tranche Two [Member]</link:label>
    <link:label id="lab_cik0001563922_EarnoutPeriodTrancheTwoMember_documentation_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodTrancheTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Earnout Period, Tranche Two</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_EarnoutPeriodTrancheTwoMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_EarnoutPeriodTrancheTwoMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_EarnoutPeriodTrancheTwoMember" xlink:to="lab_cik0001563922_EarnoutPeriodTrancheTwoMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CurrentIncomeTaxExpenseBenefit_019f7115-c6fc-7318-b018-7bf9eeaba6bc_totalLabel_en-US" xlink:label="lab_us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Current (benefit) provision for income taxes</link:label>
    <link:label id="lab_us-gaap_CurrentIncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Current Income Tax Expense (Benefit)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:to="lab_us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_019f7115-c555-70a0-9c4d-c71c6e3c1e9c_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total assets</link:label>
    <link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_019f7115-c555-70b2-b414-e786b0259298_totalLabel_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total assets</link:label>
    <link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_label_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Assets</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation"/>
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    <link:label id="lab_us-gaap_ConcentrationRiskPercentage1_019f7115-c671-763b-a79b-82f4a5a98735_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskPercentage1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Concentration risk percentage</link:label>
    <link:label id="lab_us-gaap_ConcentrationRiskPercentage1_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskPercentage1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk, Percentage</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1"/>
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    <link:label id="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019f7115-c671-7081-9eba-f3b294bc9066_negatedLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Less: Total unamortized discount and deferred financing costs</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
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    <link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets_019f7115-c555-7915-b377-784f4dc42460_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Other current and noncurrent assets</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Other Operating Assets</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
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    <link:label id="lab_us-gaap_ConsolidationPolicyTextBlock_019f7115-c671-774b-a9ed-f70198b45b42_terseLabel_en-US" xlink:label="lab_us-gaap_ConsolidationPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Basis of Consolidation</link:label>
    <link:label id="lab_us-gaap_ConsolidationPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_ConsolidationPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidation, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsolidationPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConsolidationPolicyTextBlock"/>
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    <link:label id="lab_us-gaap_ShareBasedCompensation_019f7115-c554-7c6e-8fe5-309fab914de6_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based compensation expense</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensation_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement, Noncash Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensation" xlink:to="lab_us-gaap_ShareBasedCompensation" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DistributionMadeToLimitedPartnerLineItems_019f7115-c5e8-7c39-9e4b-d97d6ec5f1bb_terseLabel_en-US" xlink:label="lab_us-gaap_DistributionMadeToLimitedPartnerLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distribution Made to Limited Partner [Line Items]</link:label>
    <link:label id="lab_us-gaap_DistributionMadeToLimitedPartnerLineItems_label_en-US" xlink:label="lab_us-gaap_DistributionMadeToLimitedPartnerLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distribution Made to Limited Partner [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DistributionMadeToLimitedPartnerLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DistributionMadeToLimitedPartnerLineItems"/>
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    <link:label id="lab_us-gaap_DerivativeAssetNotionalAmount_019f7115-c6fc-7a99-abf7-2d017f8626c7_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssetNotionalAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Outstanding notional amount</link:label>
    <link:label id="lab_us-gaap_DerivativeAssetNotionalAmount_label_en-US" xlink:label="lab_us-gaap_DerivativeAssetNotionalAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Asset, Notional Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotionalAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetNotionalAmount"/>
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    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019f7115-c5e8-7f49-ae63-443e3106a236_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Percentage</link:label>
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    <link:label id="lab_us-gaap_DividendsCommonStockCash_label_en-US" xlink:label="lab_us-gaap_DividendsCommonStockCash" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dividends, Common Stock, Cash</link:label>
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    <link:label id="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTable_label_en-US" xlink:label="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule Of Finite-Lived Out-of-Market Contracts, Intangible Liabilities [Table]</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTable" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTable"/>
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    <link:label id="lab_us-gaap_ConcentrationRiskCreditRisk_019f7115-c671-7095-b4aa-11ae3143f52d_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskCreditRisk" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Concentration of Risk</link:label>
    <link:label id="lab_us-gaap_ConcentrationRiskCreditRisk_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskCreditRisk" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk, Credit Risk, Policy [Policy Text Block]</link:label>
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    <link:label id="lab_us-gaap_DeferredTaxLiabilitiesDerivatives_019f7115-c6fc-7927-871a-80a87d086edb_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesDerivatives" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Derivative assets</link:label>
    <link:label id="lab_us-gaap_DeferredTaxLiabilitiesDerivatives_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesDerivatives" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Liabilities, Derivatives</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesDerivatives" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesDerivatives"/>
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    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019f7115-c6fc-7405-89be-3c414c6ac24e_verboseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Liabilities and Equity</link:label>
    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Liabilities and Equity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StateAndLocalJurisdictionMember_019f7115-c6fc-7bbb-be20-fbd3d26e59c3_terseLabel_en-US" xlink:label="lab_us-gaap_StateAndLocalJurisdictionMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">State and Local Jurisdiction</link:label>
    <link:label id="lab_us-gaap_StateAndLocalJurisdictionMember_label_en-US" xlink:label="lab_us-gaap_StateAndLocalJurisdictionMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">State and Local Jurisdiction [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StateAndLocalJurisdictionMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StateAndLocalJurisdictionMember" xlink:to="lab_us-gaap_StateAndLocalJurisdictionMember" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_CoverAbstract_019f7115-c5e8-7566-930e-3e5c0610eb59_terseLabel_en-US" xlink:label="lab_dei_CoverAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cover [Abstract]</link:label>
    <link:label id="lab_dei_CoverAbstract_label_en-US" xlink:label="lab_dei_CoverAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cover [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CoverAbstract"/>
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    <link:label id="lab_srt_MaximumMember_019f7115-c76d-714d-8ccc-396aabbe56d9_terseLabel_en-US" xlink:label="lab_srt_MaximumMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Maximum</link:label>
    <link:label id="lab_srt_MaximumMember_label_en-US" xlink:label="lab_srt_MaximumMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Maximum [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_MaximumMember" xlink:to="lab_srt_MaximumMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis_019f7115-c6fc-7d2b-a7f0-9cfacbd1fa68_terseLabel_en-US" xlink:label="lab_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impaired Long-Lived Assets Held and Used by Type [Axis]</link:label>
    <link:label id="lab_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis_label_en-US" xlink:label="lab_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Impaired Long-Lived Assets Held and Used by Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis" xlink:to="lab_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioAxis_019f7115-c5e8-7bb6-9472-4d63796179c7_terseLabel_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Fee Arrangement, Scenario [Axis]</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioAxis_label_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Fee Arrangement, Scenario [Axis]</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioAxis_documentation_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioAxis" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Fee Arrangement, Scenario</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioAxis" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RelatedPartyTransactionFeeArrangementScenarioAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioAxis" xlink:to="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019f7115-c555-7d7f-b0c7-fb73638dd81c_terseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net income (loss) attributable to noncontrolling interest</link:label>
    <link:label id="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019f7115-c555-7893-b060-b13d097beb77_verboseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Net income (loss) attributable to NCI</link:label>
    <link:label id="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss) Attributable to Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
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    <link:label id="lab_us-gaap_BridgeLoanMember_019f7115-c671-7b67-b626-ee3e1bad1750_terseLabel_en-US" xlink:label="lab_us-gaap_BridgeLoanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Bridge Loan</link:label>
    <link:label id="lab_us-gaap_BridgeLoanMember_label_en-US" xlink:label="lab_us-gaap_BridgeLoanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Bridge Loan [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BridgeLoanMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BridgeLoanMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BridgeLoanMember" xlink:to="lab_us-gaap_BridgeLoanMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_BaseManagementFeesPayableMonthlyRate_019f7115-c6fc-720d-8504-3004572c8349_terseLabel_en-US" xlink:label="lab_cik0001563922_BaseManagementFeesPayableMonthlyRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Base management fees payable, monthly rate</link:label>
    <link:label id="lab_cik0001563922_BaseManagementFeesPayableMonthlyRate_label_en-US" xlink:label="lab_cik0001563922_BaseManagementFeesPayableMonthlyRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Base Management Fees Payable, Monthly Rate</link:label>
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    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsNet_019f7115-c671-77e1-a6ae-1297d51d32a0_totalLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net intangible assets</link:label>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsNet_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
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    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionAmortizationOfLoanOriginationCost_019f7115-c5e8-7bc3-8513-19e9c6c49d0b_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionAmortizationOfLoanOriginationCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amortization of loan origination cost</link:label>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionAmortizationOfLoanOriginationCost_label_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionAmortizationOfLoanOriginationCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale And Leaseback Transaction, Amortization of Loan Origination Cost</link:label>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionAmortizationOfLoanOriginationCost_documentation_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionAmortizationOfLoanOriginationCost" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale And Leaseback Transaction, Amortization of Loan Origination Cost</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleAndLeasebackTransactionAmortizationOfLoanOriginationCost" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleAndLeasebackTransactionAmortizationOfLoanOriginationCost"/>
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    <link:label id="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet_019f7115-c671-7856-a04d-617ac9e00a89_terseLabel_en-US" xlink:label="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income from sale-leaseback transfer of tax benefits</link:label>
    <link:label id="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet_019f7115-c671-7290-929d-f39155b567ec_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Income from sale-leaseback transfer of tax benefits</link:label>
    <link:label id="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet_label_en-US" xlink:label="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale and Leaseback Transaction, Gain (Loss), Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleAndLeasebackTransactionGainLossNet"/>
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    <link:label id="lab_us-gaap_DebtInstrumentLineItems_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentLineItems" xlink:to="lab_us-gaap_DebtInstrumentLineItems" xlink:type="arc" order="1"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
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    <link:label id="lab_cik0001563922_RenewableEnergyCreditAndOtherIncentivesMember_019f7115-c554-7df9-91af-f9802bd3f295_terseLabel_en-US" xlink:label="lab_cik0001563922_RenewableEnergyCreditAndOtherIncentivesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">RECs and other incentives</link:label>
    <link:label id="lab_cik0001563922_RenewableEnergyCreditAndOtherIncentivesMember_label_en-US" xlink:label="lab_cik0001563922_RenewableEnergyCreditAndOtherIncentivesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Renewable Energy Credit And Other Incentives [Member]</link:label>
    <link:label id="lab_cik0001563922_RenewableEnergyCreditAndOtherIncentivesMember_documentation_en-US" xlink:label="lab_cik0001563922_RenewableEnergyCreditAndOtherIncentivesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Renewable Energy Credit And Other Incentives</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RenewableEnergyCreditAndOtherIncentivesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RenewableEnergyCreditAndOtherIncentivesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RenewableEnergyCreditAndOtherIncentivesMember" xlink:to="lab_cik0001563922_RenewableEnergyCreditAndOtherIncentivesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredCostsCurrentAndNoncurrent_019f7115-c6fc-799d-852a-1d8cba4d65e9_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredCostsCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred sales commission</link:label>
    <link:label id="lab_us-gaap_DeferredCostsCurrentAndNoncurrent_label_en-US" xlink:label="lab_us-gaap_DeferredCostsCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCostsCurrentAndNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCostsCurrentAndNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredCostsCurrentAndNoncurrent" xlink:to="lab_us-gaap_DeferredCostsCurrentAndNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationPermanentDifferencesAmount_019f7115-c5e8-7ea6-a3c9-dc5178511232_negatedLabel_en-US" xlink:label="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationPermanentDifferencesAmount" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Permanent differences (other - net)</link:label>
    <link:label id="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationPermanentDifferencesAmount_label_en-US" xlink:label="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationPermanentDifferencesAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Permanent Differences, Amount</link:label>
    <link:label id="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationPermanentDifferencesAmount_documentation_en-US" xlink:label="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationPermanentDifferencesAmount" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Permanent Differences, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_EffectiveIncomeTaxRateReconciliationPermanentDifferencesAmount" xlink:href="cik0001563922-20260810.xsd#cik0001563922_EffectiveIncomeTaxRateReconciliationPermanentDifferencesAmount"/>
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    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationAfterRollingYearFive_019f7115-c76d-76e2-b7b4-4dcfbbf71656_terseLabel_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Thereafter</link:label>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationAfterRollingYearFive_label_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets And Liabilities, Net, Expected Amortization, After Rolling Year Five</link:label>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationAfterRollingYearFive_documentation_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets And Liabilities, Net, Expected Amortization, After Rolling Year Five</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationAfterRollingYearFive" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationAfterRollingYearFive"/>
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    <link:label id="lab_cik0001563922_BatteryStorageAssetMember_019f7115-c671-78d1-9e60-1552a222f860_terseLabel_en-US" xlink:label="lab_cik0001563922_BatteryStorageAssetMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Battery storage systems</link:label>
    <link:label id="lab_cik0001563922_BatteryStorageAssetMember_label_en-US" xlink:label="lab_cik0001563922_BatteryStorageAssetMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Battery Storage Asset [Member]</link:label>
    <link:label id="lab_cik0001563922_BatteryStorageAssetMember_documentation_en-US" xlink:label="lab_cik0001563922_BatteryStorageAssetMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Battery Storage Asset</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_BatteryStorageAssetMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_BatteryStorageAssetMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_BatteryStorageAssetMember" xlink:to="lab_cik0001563922_BatteryStorageAssetMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InterestIncomeDepositsWithFinancialInstitutions_019f7115-c671-794e-ad2c-36ff4bce66ab_negatedLabel_en-US" xlink:label="lab_us-gaap_InterestIncomeDepositsWithFinancialInstitutions" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Interest income, deposits with financial institutions</link:label>
    <link:label id="lab_us-gaap_InterestIncomeDepositsWithFinancialInstitutions_label_en-US" xlink:label="lab_us-gaap_InterestIncomeDepositsWithFinancialInstitutions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Income, Deposits with Financial Institutions</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeDepositsWithFinancialInstitutions" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeDepositsWithFinancialInstitutions"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestIncomeDepositsWithFinancialInstitutions" xlink:to="lab_us-gaap_InterestIncomeDepositsWithFinancialInstitutions" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_LongTermContractForPurchaseOfElectricPowerTermOfContract_019f7115-c671-72ce-ac92-16fc1a0c7d6e_terseLabel_en-US" xlink:label="lab_cik0001563922_LongTermContractForPurchaseOfElectricPowerTermOfContract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Power purchase agreement, term of contract (in years)</link:label>
    <link:label id="lab_cik0001563922_LongTermContractForPurchaseOfElectricPowerTermOfContract_label_en-US" xlink:label="lab_cik0001563922_LongTermContractForPurchaseOfElectricPowerTermOfContract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Contract for Purchase Of Electric Power, Term Of Contract</link:label>
    <link:label id="lab_cik0001563922_LongTermContractForPurchaseOfElectricPowerTermOfContract_documentation_en-US" xlink:label="lab_cik0001563922_LongTermContractForPurchaseOfElectricPowerTermOfContract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Long-Term Contract for Purchase Of Electric Power, Term Of Contract</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_LongTermContractForPurchaseOfElectricPowerTermOfContract" xlink:href="cik0001563922-20260810.xsd#cik0001563922_LongTermContractForPurchaseOfElectricPowerTermOfContract"/>
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    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent_019f7115-c5e8-7880-bf1b-2301a63462d1_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total noncurrent liabilities</link:label>
    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent_label_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent"/>
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    <link:label id="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f7115-c5e8-7fad-977b-cc1bcbbebb70_totalLabel_en-US" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Loss before income taxes</link:label>
    <link:label id="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
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    <link:label id="lab_us-gaap_DebtInstrumentTable_019f7115-c76d-7348-ab5b-2458229ff0b9_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Long-term Debt Instruments [Table]</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentTable_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Long-Term Debt Instruments [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentTable" xlink:to="lab_us-gaap_DebtInstrumentTable" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilities_019f7115-c554-70bf-8658-1215b94917d7_verboseLabel_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilities" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Operating lease liabilities</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilities_label_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Operating Lease Liabilities</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilities_documentation_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilities" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Operating Lease Liabilities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilities" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingLeaseLiabilities"/>
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    <link:label id="lab_us-gaap_StatementOfStockholdersEquityAbstract_019f7115-c6fc-79d4-a8e9-c18bf9aa6381_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement of Stockholders' Equity [Abstract]</link:label>
    <link:label id="lab_us-gaap_StatementOfStockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Stockholders' Equity [Abstract]</link:label>
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    <link:label id="lab_us-gaap_OperatingSegmentsMember_019f7115-c5e8-7af6-9191-ed6133cbc2d0_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingSegmentsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Segments</link:label>
    <link:label id="lab_us-gaap_OperatingSegmentsMember_label_en-US" xlink:label="lab_us-gaap_OperatingSegmentsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Segments [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
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    <link:label id="lab_cik0001563922_ScheduleOfMaturitiesOfSaleLeasebackTransactionsTableTextBlock_019f7115-c555-7591-b7f9-13bb761332e1_terseLabel_en-US" xlink:label="lab_cik0001563922_ScheduleOfMaturitiesOfSaleLeasebackTransactionsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Future Payments on Sale-Leaseback Financing Arrangements</link:label>
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    <link:label id="lab_us-gaap_AssetRetirementObligationsPolicy_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Retirement Obligation [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetRetirementObligationsPolicy"/>
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    <link:label id="lab_us-gaap_LetterOfCreditMember_019f7115-c5e8-774b-8d25-917dcf7aac1a_terseLabel_en-US" xlink:label="lab_us-gaap_LetterOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Letter of Credit</link:label>
    <link:label id="lab_us-gaap_LetterOfCreditMember_label_en-US" xlink:label="lab_us-gaap_LetterOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Letter of Credit [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LetterOfCreditMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LetterOfCreditMember" xlink:to="lab_us-gaap_LetterOfCreditMember" xlink:type="arc" order="1"/>
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    <link:label id="lab_us-gaap_PaymentsToMinorityShareholders_019f7115-c5e8-700d-a665-a5ef07c04a6e_terseLabel_en-US" xlink:label="lab_us-gaap_PaymentsToMinorityShareholders" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distributions to Tax Equity Investors, paid</link:label>
    <link:label id="lab_us-gaap_PaymentsToMinorityShareholders_label_en-US" xlink:label="lab_us-gaap_PaymentsToMinorityShareholders" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments to Noncontrolling Interests</link:label>
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    <link:label id="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_019f7115-c554-78c1-9d04-b8e49ec0faa9_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">United States</link:label>
    <link:label id="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_label_en-US" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income (Loss) from Continuing Operations before Income Taxes, Domestic</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic"/>
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    <link:label id="lab_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_019f7115-c6fc-726f-9395-26203b1fb0fe_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Share-Based Compensation Expense</link:label>
    <link:label id="lab_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock"/>
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    <link:label id="lab_us-gaap_OperatingLeaseLiabilityCurrent_019f7115-c5e8-7dd8-8e91-9caf712396ae_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityCurrent" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Operating lease liabilities, current</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLiabilityCurrent_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Liability, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiabilityCurrent" xlink:to="lab_us-gaap_OperatingLeaseLiabilityCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseInterestExpense_019f7115-c555-74a8-9ee5-10cb22cb6b2a_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseInterestExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest on lease liabilities</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseInterestExpense_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseInterestExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Interest Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseInterestExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseInterestExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseInterestExpense" xlink:to="lab_us-gaap_FinanceLeaseInterestExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingROUAssetsNet_019f7115-c554-79d1-84c5-b9b631549452_terseLabel_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingROUAssetsNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating ROU assets, net</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingROUAssetsNet_label_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingROUAssetsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Operating ROU Assets, Net</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingROUAssetsNet_documentation_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingROUAssetsNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Operating ROU Assets, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingROUAssetsNet" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DisposalGroupIncludingDiscontinuedOperationOperatingROUAssetsNet"/>
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    <link:label id="lab_us-gaap_NameOfReceivableWithImputedInterestDomain_019f7115-c5e8-7b05-890d-5131f52d271b_terseLabel_en-US" xlink:label="lab_us-gaap_NameOfReceivableWithImputedInterestDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Name of Receivable with Imputed Interest [Domain]</link:label>
    <link:label id="lab_us-gaap_NameOfReceivableWithImputedInterestDomain_label_en-US" xlink:label="lab_us-gaap_NameOfReceivableWithImputedInterestDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Name of Receivable with Imputed Interest [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NameOfReceivableWithImputedInterestDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NameOfReceivableWithImputedInterestDomain"/>
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    <link:label id="lab_us-gaap_DerivativesFairValueLineItems_019f7115-c6fc-716e-a93c-b6cd34d3bde5_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativesFairValueLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivatives, Fair Value [Line Items]</link:label>
    <link:label id="lab_us-gaap_DerivativesFairValueLineItems_label_en-US" xlink:label="lab_us-gaap_DerivativesFairValueLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivatives, Fair Value [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativesFairValueLineItems"/>
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    <link:label id="lab_cik0001563922_FinancingReceivableMembershipInterest_019f7115-c6fc-79d9-8642-444203f835a9_terseLabel_en-US" xlink:label="lab_cik0001563922_FinancingReceivableMembershipInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Membership interest</link:label>
    <link:label id="lab_cik0001563922_FinancingReceivableMembershipInterest_label_en-US" xlink:label="lab_cik0001563922_FinancingReceivableMembershipInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Financing Receivable, Membership Interest</link:label>
    <link:label id="lab_cik0001563922_FinancingReceivableMembershipInterest_documentation_en-US" xlink:label="lab_cik0001563922_FinancingReceivableMembershipInterest" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Financing Receivable, Membership Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FinancingReceivableMembershipInterest" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FinancingReceivableMembershipInterest"/>
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    <link:label id="lab_cik0001563922_BankruptcyClaimAbstract_019f7115-c5e8-74e3-9c75-f521bf841c56_terseLabel_en-US" xlink:label="lab_cik0001563922_BankruptcyClaimAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">OYA bankruptcy claim receivable</link:label>
    <link:label id="lab_cik0001563922_BankruptcyClaimAbstract_label_en-US" xlink:label="lab_cik0001563922_BankruptcyClaimAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Bankruptcy Claim [Abstract]</link:label>
    <link:label id="lab_cik0001563922_BankruptcyClaimAbstract_documentation_en-US" xlink:label="lab_cik0001563922_BankruptcyClaimAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Bankruptcy Claim</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_BankruptcyClaimAbstract" xlink:href="cik0001563922-20260810.xsd#cik0001563922_BankruptcyClaimAbstract"/>
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    <link:label id="lab_cik0001563922_RelatedPartyTransactionTransitionServicesAgreementFee_019f7115-c555-7651-be9a-c43d573d109e_terseLabel_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionTransitionServicesAgreementFee" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fee (usd per hour)</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionTransitionServicesAgreementFee_label_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionTransitionServicesAgreementFee" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Transition Services Agreement, Fee</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionTransitionServicesAgreementFee_documentation_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionTransitionServicesAgreementFee" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Transition Services Agreement, Fee</link:label>
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    <link:label id="lab_us-gaap_DistributionsMadeToLimitedPartnerTable_019f7115-c76d-7782-b28c-b3e3c363cadb_terseLabel_en-US" xlink:label="lab_us-gaap_DistributionsMadeToLimitedPartnerTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distributions Made to Limited Partner [Table]</link:label>
    <link:label id="lab_us-gaap_DistributionsMadeToLimitedPartnerTable_label_en-US" xlink:label="lab_us-gaap_DistributionsMadeToLimitedPartnerTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distributions Made to Limited Partner [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DistributionsMadeToLimitedPartnerTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DistributionsMadeToLimitedPartnerTable"/>
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    <link:label id="lab_cik0001563922_GRECEntityHoldcoLLCMember_019f7115-c5e8-7cfa-9af5-5c6f1f1a3a1d_terseLabel_en-US" xlink:label="lab_cik0001563922_GRECEntityHoldcoLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GREC Entity HoldCo LLC</link:label>
    <link:label id="lab_cik0001563922_GRECEntityHoldcoLLCMember_label_en-US" xlink:label="lab_cik0001563922_GRECEntityHoldcoLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">GREC Entity Holdco LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_GRECEntityHoldcoLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_GRECEntityHoldcoLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information about energy efficiency portfolio.</link:label>
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    <link:label id="lab_us-gaap_AwardTypeAxis_019f7115-c76d-7085-b6fd-18865653b9d7_terseLabel_en-US" xlink:label="lab_us-gaap_AwardTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Award Type [Axis]</link:label>
    <link:label id="lab_us-gaap_AwardTypeAxis_label_en-US" xlink:label="lab_us-gaap_AwardTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Award Type [Axis]</link:label>
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    <link:label id="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsPerformancePeriod_documentation_en-US" xlink:label="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsPerformancePeriod" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Performance Period</link:label>
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    <link:label id="lab_cik0001563922_PRCNemasketLLCMember_label_en-US" xlink:label="lab_cik0001563922_PRCNemasketLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">PRC Nemasket LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_PRCNemasketLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_PRCNemasketLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">PRC Nemasket LLC</link:label>
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    <link:label id="lab_srt_EquityMethodInvesteeNameDomain_label_en-US" xlink:label="lab_srt_EquityMethodInvesteeNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investment, Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain"/>
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    <link:label id="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_019f7115-c6fc-7174-9502-d4869cc95913_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy"/>
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    <link:label id="lab_cik0001563922_TaxCreditTransferLiabilityCurrent_label_en-US" xlink:label="lab_cik0001563922_TaxCreditTransferLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Tax Credit Transfer Liability, Current</link:label>
    <link:label id="lab_cik0001563922_TaxCreditTransferLiabilityCurrent_documentation_en-US" xlink:label="lab_cik0001563922_TaxCreditTransferLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tax Credit Transfer Liability, Current</link:label>
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    <link:label id="lab_us-gaap_BusinessCombinationsPolicy_019f7115-c555-760e-843b-1d7639304c48_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationsPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Acquisitions</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationsPolicy_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Combination [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsPolicy"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationsPolicy" xlink:to="lab_us-gaap_BusinessCombinationsPolicy" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_019f7115-c555-79ac-b8ec-748f530266e6_verboseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Change in valuation allowance</link:label>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
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    <link:label id="lab_us-gaap_SaleOfSubsidiaryGainLossMember_019f7115-c6fc-7a86-a6bb-87029c990c28_terseLabel_en-US" xlink:label="lab_us-gaap_SaleOfSubsidiaryGainLossMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Sale of Subsidiary Gain (Loss)</link:label>
    <link:label id="lab_us-gaap_SaleOfSubsidiaryGainLossMember_label_en-US" xlink:label="lab_us-gaap_SaleOfSubsidiaryGainLossMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale of Subsidiary Gain (Loss) [Member]</link:label>
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    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019f7115-c5e8-7ac5-a217-5eaeef154f39_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Issuance of shares related to share-based compensation (in shares)</link:label>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent"/>
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    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive_019f7115-c671-75f4-ad89-d3b7ebc2ac7d_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2030-2031</link:label>
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    <link:label id="lab_cik0001563922_Gemstone2025ManagerLLCMember_019f7115-c555-7a47-ba3e-2e1d8634def0_terseLabel_en-US" xlink:label="lab_cik0001563922_Gemstone2025ManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Gemstone 2025 Manager LLC</link:label>
    <link:label id="lab_cik0001563922_Gemstone2025ManagerLLCMember_label_en-US" xlink:label="lab_cik0001563922_Gemstone2025ManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gemstone 2025 Manager LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_Gemstone2025ManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_Gemstone2025ManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Gemstone 2025 Manager LLC</link:label>
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    <link:label id="lab_us-gaap_DeferredTaxAssetsNet_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Net of Valuation Allowance</link:label>
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    <link:label id="lab_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_019f7115-c6fc-7236-9806-29df8f030bab_terseLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]</link:label>
    <link:label id="lab_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward"/>
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    <link:label id="lab_us-gaap_IncomeStatementLocationDomain_label_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Income Location, Balance [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
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    <link:label id="lab_us-gaap_RestrictedStockUnitsRSUMember_019f7115-c5e8-7014-b946-d1e8374e79b4_terseLabel_en-US" xlink:label="lab_us-gaap_RestrictedStockUnitsRSUMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Restricted stock units</link:label>
    <link:label id="lab_us-gaap_RestrictedStockUnitsRSUMember_019f7115-c5e8-7cd1-8fd7-cb02779189fb_verboseLabel_en-US" xlink:label="lab_us-gaap_RestrictedStockUnitsRSUMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Restricted Share Units</link:label>
    <link:label id="lab_us-gaap_RestrictedStockUnitsRSUMember_label_en-US" xlink:label="lab_us-gaap_RestrictedStockUnitsRSUMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restricted Stock Units (RSUs) [Member]</link:label>
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    <link:label id="lab_cik0001563922_PremiumFinancingLoanMember_019f7115-c6fc-7821-bd70-d51d5cdf238f_terseLabel_en-US" xlink:label="lab_cik0001563922_PremiumFinancingLoanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Premium Financing Loan</link:label>
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    <link:label id="lab_cik0001563922_PremiumFinancingLoanMember_documentation_en-US" xlink:label="lab_cik0001563922_PremiumFinancingLoanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Premium Financing Loan</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeveranceCosts1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeveranceCosts1"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SeveranceCosts1" xlink:to="lab_us-gaap_SeveranceCosts1" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPIILLCGDEVGPIIMember_019f7115-c671-701a-b0b6-3158b1b1ab79_terseLabel_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPIILLCGDEVGPIIMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GDEV GP II</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPIILLCGDEVGPIIMember_label_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPIILLCGDEVGPIIMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities GP II, LLC ("GDEV GP II") [Member]</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPIILLCGDEVGPIIMember_documentation_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPIILLCGDEVGPIIMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities GP II, LLC ("GDEV GP II")</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GreenbackerDevelopmentOpportunitiesGPIILLCGDEVGPIIMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GreenbackerDevelopmentOpportunitiesGPIILLCGDEVGPIIMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GreenbackerDevelopmentOpportunitiesGPIILLCGDEVGPIIMember" xlink:to="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPIILLCGDEVGPIIMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CreditLossFinancialInstrumentPolicyTextBlock_019f7115-c5e8-7161-bad6-5b28582640d5_terseLabel_en-US" xlink:label="lab_us-gaap_CreditLossFinancialInstrumentPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Allowance for Credit Losses</link:label>
    <link:label id="lab_us-gaap_CreditLossFinancialInstrumentPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_CreditLossFinancialInstrumentPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Credit Loss, Financial Instrument [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditLossFinancialInstrumentPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditLossFinancialInstrumentPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CreditLossFinancialInstrumentPolicyTextBlock" xlink:to="lab_us-gaap_CreditLossFinancialInstrumentPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityEmergingGrowthCompany_019f7115-c671-79e8-b285-08b9e005775b_terseLabel_en-US" xlink:label="lab_dei_EntityEmergingGrowthCompany" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Emerging Growth Company</link:label>
    <link:label id="lab_dei_EntityEmergingGrowthCompany_label_en-US" xlink:label="lab_dei_EntityEmergingGrowthCompany" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Emerging Growth Company</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityEmergingGrowthCompany" xlink:to="lab_dei_EntityEmergingGrowthCompany" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RedemptionPayableIncurredButNotYetPaid_019f7115-c6fc-73ea-b506-5a99b444ac42_terseLabel_en-US" xlink:label="lab_cik0001563922_RedemptionPayableIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Redemptions payable</link:label>
    <link:label id="lab_cik0001563922_RedemptionPayableIncurredButNotYetPaid_label_en-US" xlink:label="lab_cik0001563922_RedemptionPayableIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Redemption Payable Incurred But Not Yet Paid</link:label>
    <link:label id="lab_cik0001563922_RedemptionPayableIncurredButNotYetPaid_documentation_en-US" xlink:label="lab_cik0001563922_RedemptionPayableIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Redemption Payable Incurred But Not Yet Paid</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RedemptionPayableIncurredButNotYetPaid" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RedemptionPayableIncurredButNotYetPaid"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RedemptionPayableIncurredButNotYetPaid" xlink:to="lab_cik0001563922_RedemptionPayableIncurredButNotYetPaid" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_019f7115-c671-758c-9d80-7d72141f133f_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Weighted-average remaining lease term - finance leases (in years)</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Weighted Average Remaining Lease Term</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="lab_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_IndependentContractorMembershipInterestMember_019f7115-c6fc-7b2c-85b6-4fda01929b6e_terseLabel_en-US" xlink:label="lab_cik0001563922_IndependentContractorMembershipInterestMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Independent contractor membership interest</link:label>
    <link:label id="lab_cik0001563922_IndependentContractorMembershipInterestMember_label_en-US" xlink:label="lab_cik0001563922_IndependentContractorMembershipInterestMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Independent Contractor Membership Interest [Member]</link:label>
    <link:label id="lab_cik0001563922_IndependentContractorMembershipInterestMember_documentation_en-US" xlink:label="lab_cik0001563922_IndependentContractorMembershipInterestMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Independent Contractor Membership Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_IndependentContractorMembershipInterestMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_IndependentContractorMembershipInterestMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_IndependentContractorMembershipInterestMember" xlink:to="lab_cik0001563922_IndependentContractorMembershipInterestMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherCommitmentDueInThirdYear_019f7115-c76d-70f7-b72e-56c1e37ce92e_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCommitmentDueInThirdYear" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2028-2029</link:label>
    <link:label id="lab_us-gaap_OtherCommitmentDueInThirdYear_label_en-US" xlink:label="lab_us-gaap_OtherCommitmentDueInThirdYear" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Commitment, to be Paid, Year Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentDueInThirdYear" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentDueInThirdYear"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCommitmentDueInThirdYear" xlink:to="lab_us-gaap_OtherCommitmentDueInThirdYear" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_IndependentPowerProducerIPPSegmentMember_019f7115-c671-77b5-9d8b-8842be212425_terseLabel_en-US" xlink:label="lab_cik0001563922_IndependentPowerProducerIPPSegmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Independent Power Producer ("IPP") Segment</link:label>
    <link:label id="lab_cik0001563922_IndependentPowerProducerIPPSegmentMember_019f7115-c671-7bf0-b587-205a6cbe5e17_verboseLabel_en-US" xlink:label="lab_cik0001563922_IndependentPowerProducerIPPSegmentMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Independent Power Producer</link:label>
    <link:label id="lab_cik0001563922_IndependentPowerProducerIPPSegmentMember_label_en-US" xlink:label="lab_cik0001563922_IndependentPowerProducerIPPSegmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Independent Power Producer ("IPP") Segment [Member]</link:label>
    <link:label id="lab_cik0001563922_IndependentPowerProducerIPPSegmentMember_documentation_en-US" xlink:label="lab_cik0001563922_IndependentPowerProducerIPPSegmentMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Independent Power Producer ("IPP") Segment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_IndependentPowerProducerIPPSegmentMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_IndependentPowerProducerIPPSegmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_IndependentPowerProducerIPPSegmentMember" xlink:to="lab_cik0001563922_IndependentPowerProducerIPPSegmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DepositPaymentsToAcquirePropertyPlantAndEquipmentNet_019f7115-c555-7b1e-9526-0b7d343bb728_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_DepositPaymentsToAcquirePropertyPlantAndEquipmentNet" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Net deposits (paid) returned for property, plant and equipment</link:label>
    <link:label id="lab_cik0001563922_DepositPaymentsToAcquirePropertyPlantAndEquipmentNet_label_en-US" xlink:label="lab_cik0001563922_DepositPaymentsToAcquirePropertyPlantAndEquipmentNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deposit Payments To Acquire Property, Plant, And Equipment, Net</link:label>
    <link:label id="lab_cik0001563922_DepositPaymentsToAcquirePropertyPlantAndEquipmentNet_documentation_en-US" xlink:label="lab_cik0001563922_DepositPaymentsToAcquirePropertyPlantAndEquipmentNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Deposit Payments To Acquire Property, Plant, And Equipment, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DepositPaymentsToAcquirePropertyPlantAndEquipmentNet" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DepositPaymentsToAcquirePropertyPlantAndEquipmentNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DepositPaymentsToAcquirePropertyPlantAndEquipmentNet" xlink:to="lab_cik0001563922_DepositPaymentsToAcquirePropertyPlantAndEquipmentNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommonClassCMember_019f7115-c671-7558-9edf-1ee926ab49ad_verboseLabel_en-US" xlink:label="lab_us-gaap_CommonClassCMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Class C</link:label>
    <link:label id="lab_us-gaap_CommonClassCMember_019f7115-c671-7de1-a5ec-8b3acae9e4d5_terseLabel_en-US" xlink:label="lab_us-gaap_CommonClassCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class C</link:label>
    <link:label id="lab_us-gaap_CommonClassCMember_label_en-US" xlink:label="lab_us-gaap_CommonClassCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Class C [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassCMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonClassCMember" xlink:to="lab_us-gaap_CommonClassCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_019f7115-c6fc-71d9-80e4-c5a9f2fc627a_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Less: Imputed interest</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, Undiscounted Excess Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:to="lab_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CiderProjectMember_019fa44a-3ec1-7f5d-b0e6-e957bc9fa7d7_terseLabel_en-US" xlink:label="lab_cik0001563922_CiderProjectMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cider Solar AcquisitionCo LLC(1)</link:label>
    <link:label id="lab_cik0001563922_CiderProjectMember_label_en-US" xlink:label="lab_cik0001563922_CiderProjectMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cider Project [Member]</link:label>
    <link:label id="lab_cik0001563922_CiderProjectMember_documentation_en-US" xlink:label="lab_cik0001563922_CiderProjectMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cider Project</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CiderProjectMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CiderProjectMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CiderProjectMember" xlink:to="lab_cik0001563922_CiderProjectMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommonStockSharesOutstanding_019f7115-c554-7486-ad1c-ae187e5e5d8d_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common shares, shares outstanding (in shares)</link:label>
    <link:label id="lab_us-gaap_CommonStockSharesOutstanding_019f7115-c554-7797-9f01-29780bb6197e_periodStartLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Beginning balance (in shares)</link:label>
    <link:label id="lab_us-gaap_CommonStockSharesOutstanding_019f7115-c554-70fe-927d-fc22e96d4601_periodEndLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Ending balance (in shares)</link:label>
    <link:label id="lab_us-gaap_CommonStockSharesOutstanding_label_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock, Shares, Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesOutstanding" xlink:to="lab_us-gaap_CommonStockSharesOutstanding" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_GainLossOnSaleOfOtherAssets_019f7115-c554-7e10-9131-cdfbfdaf6489_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfOtherAssets" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">(Gain) loss on asset disposition</link:label>
    <link:label id="lab_us-gaap_GainLossOnSaleOfOtherAssets_label_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfOtherAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Disposition of Other Assets</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfOtherAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnSaleOfOtherAssets"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GainLossOnSaleOfOtherAssets" xlink:to="lab_us-gaap_GainLossOnSaleOfOtherAssets" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InterestRateSwaptionMember_019f7115-c671-71d0-8ad5-b0d022907bfe_terseLabel_en-US" xlink:label="lab_us-gaap_InterestRateSwaptionMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Option to enter into interest rate swap contract</link:label>
    <link:label id="lab_us-gaap_InterestRateSwaptionMember_label_en-US" xlink:label="lab_us-gaap_InterestRateSwaptionMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Rate Swaption [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwaptionMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateSwaptionMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestRateSwaptionMember" xlink:to="lab_us-gaap_InterestRateSwaptionMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisaggregationOfRevenueTableTextBlock_019f7115-c5e8-7fa5-b4f7-1de7598753a5_terseLabel_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Disaggregation of Revenue</link:label>
    <link:label id="lab_us-gaap_DisaggregationOfRevenueTableTextBlock_label_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disaggregation of Revenue [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTableTextBlock"/>
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    <link:label id="lab_us-gaap_LegalFees_019f7115-c555-70ce-b43f-f1da3ba8ff69_terseLabel_en-US" xlink:label="lab_us-gaap_LegalFees" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Legal fees</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
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    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsTotalNetAssets_label_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsTotalNetAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operations, Total Net Assets</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsTotalNetAssets_documentation_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsTotalNetAssets" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operations, Total Net Assets</link:label>
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    <link:label id="lab_us-gaap_GuaranteeObligationsCurrentCarryingValue_label_en-US" xlink:label="lab_us-gaap_GuaranteeObligationsCurrentCarryingValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Guarantor Obligations, Current Carrying Value</link:label>
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    <link:label id="lab_cik0001563922_DeferredTaxAssetsLongTermDebtAndFailedSaleLeasebackFinancing_019f7115-c5e8-73b9-aa82-45dcbdfd6e75_terseLabel_en-US" xlink:label="lab_cik0001563922_DeferredTaxAssetsLongTermDebtAndFailedSaleLeasebackFinancing" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-term debt and failed sale-leaseback financing</link:label>
    <link:label id="lab_cik0001563922_DeferredTaxAssetsLongTermDebtAndFailedSaleLeasebackFinancing_label_en-US" xlink:label="lab_cik0001563922_DeferredTaxAssetsLongTermDebtAndFailedSaleLeasebackFinancing" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Long-Term Debt and Failed Sale-Leaseback Financing</link:label>
    <link:label id="lab_cik0001563922_DeferredTaxAssetsLongTermDebtAndFailedSaleLeasebackFinancing_documentation_en-US" xlink:label="lab_cik0001563922_DeferredTaxAssetsLongTermDebtAndFailedSaleLeasebackFinancing" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Long-Term Debt and Failed Sale-Leaseback Financing</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DeferredTaxAssetsLongTermDebtAndFailedSaleLeasebackFinancing" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DeferredTaxAssetsLongTermDebtAndFailedSaleLeasebackFinancing"/>
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    <link:label id="lab_cik0001563922_DistributionPayableIncurredButNotYetPaid_label_en-US" xlink:label="lab_cik0001563922_DistributionPayableIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distribution Payable Incurred But Not Yet Paid</link:label>
    <link:label id="lab_cik0001563922_DistributionPayableIncurredButNotYetPaid_documentation_en-US" xlink:label="lab_cik0001563922_DistributionPayableIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Distribution Payable Incurred But Not Yet Paid</link:label>
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    <link:label id="lab_cik0001563922_FederalCapitalLossCarryforwardsMember_label_en-US" xlink:label="lab_cik0001563922_FederalCapitalLossCarryforwardsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Federal Capital Loss Carryforwards [Member]</link:label>
    <link:label id="lab_cik0001563922_FederalCapitalLossCarryforwardsMember_documentation_en-US" xlink:label="lab_cik0001563922_FederalCapitalLossCarryforwardsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Federal Capital Loss Carryforwards</link:label>
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    <link:label id="lab_cik0001563922_TaxCreditCarryforwardExpiringIn2036And2037Member_documentation_en-US" xlink:label="lab_cik0001563922_TaxCreditCarryforwardExpiringIn2036And2037Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tax Credit Carryforward, Expiring In 2036 And 2037</link:label>
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    <link:label id="lab_us-gaap_IncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_IncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax Expense (Benefit)</link:label>
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    <link:label id="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_019f7115-c6fc-7b03-b06d-4da14a62f259_periodStartLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Beginning balance</link:label>
    <link:label id="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_019f7115-c6fc-7a52-b3a4-0a76d8c46617_periodEndLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Ending balance</link:label>
    <link:label id="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_label_en-US" xlink:label="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
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    <link:label id="lab_cik0001563922_EarnoutPeriodTrancheThreeMember_019f7115-c5e8-79d5-a4c5-bb4b590e9f4b_terseLabel_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodTrancheThreeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tranche 3 Earnout Shares</link:label>
    <link:label id="lab_cik0001563922_EarnoutPeriodTrancheThreeMember_label_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodTrancheThreeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Earnout Period, Tranche Three [Member]</link:label>
    <link:label id="lab_cik0001563922_EarnoutPeriodTrancheThreeMember_documentation_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodTrancheThreeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Earnout Period, Tranche Three</link:label>
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    <link:label id="lab_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis_019f7115-c671-7bbd-b908-58d3aca734dc_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement of Financial Position Location, Activity, Capitalization [Axis]</link:label>
    <link:label id="lab_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis_label_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Financial Position Location, Activity, Capitalization [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis"/>
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    <link:label id="lab_us-gaap_PreferredStockSharesIssued_019f7115-c6fc-7ef6-b51f-755115cb7ad2_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Preferred shares, shares issued (in shares)</link:label>
    <link:label id="lab_us-gaap_PreferredStockSharesIssued_label_en-US" xlink:label="lab_us-gaap_PreferredStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred Stock, Shares Issued</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockSharesIssued" xlink:to="lab_us-gaap_PreferredStockSharesIssued" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DesignatedAsHedgingInstrumentMember_019f7115-c671-7925-987c-64028e67c2d4_terseLabel_en-US" xlink:label="lab_us-gaap_DesignatedAsHedgingInstrumentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivatives Previously Designated as Hedging Instruments</link:label>
    <link:label id="lab_us-gaap_DesignatedAsHedgingInstrumentMember_label_en-US" xlink:label="lab_us-gaap_DesignatedAsHedgingInstrumentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Designated as Hedging Instrument [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DesignatedAsHedgingInstrumentMember" xlink:to="lab_us-gaap_DesignatedAsHedgingInstrumentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GRECWarehouseHoldingsILLCMember_019f7115-c5e8-7472-9949-fade6619a21a_terseLabel_en-US" xlink:label="lab_cik0001563922_GRECWarehouseHoldingsILLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GREC Warehouse Holdings I LLC</link:label>
    <link:label id="lab_cik0001563922_GRECWarehouseHoldingsILLCMember_label_en-US" xlink:label="lab_cik0001563922_GRECWarehouseHoldingsILLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">GREC Warehouse Holdings I LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_GRECWarehouseHoldingsILLCMember_documentation_en-US" xlink:label="lab_cik0001563922_GRECWarehouseHoldingsILLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">GREC Warehouse Holdings I LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GRECWarehouseHoldingsILLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GRECWarehouseHoldingsILLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GRECWarehouseHoldingsILLCMember" xlink:to="lab_cik0001563922_GRECWarehouseHoldingsILLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f7115-c5e8-7582-943b-9d81a9f1bfe1_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV [Axis]</link:label>
    <link:label id="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis_label_en-US" xlink:label="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_019f7115-c671-7ac3-aeec-c8f6efbc024d_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amortization on derivatives previously designated as hedges and other changes in Accumulated other comprehensive income (loss), net of tax</link:label>
    <link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:to="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentGross_019f7115-c671-7ea7-b859-8ba8d91afb01_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Gross property, plant and equipment</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentGross_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment, Gross</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentGross" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentGross" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SettlementAgreementCreditForBalanceDueToVendorAmount_019f7115-c671-74af-a1cf-75ca0878c2e4_terseLabel_en-US" xlink:label="lab_cik0001563922_SettlementAgreementCreditForBalanceDueToVendorAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amount received from vendor for solar panels</link:label>
    <link:label id="lab_cik0001563922_SettlementAgreementCreditForBalanceDueToVendorAmount_label_en-US" xlink:label="lab_cik0001563922_SettlementAgreementCreditForBalanceDueToVendorAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Settlement Agreement, Credit For Balance Due to Vendor, Amount</link:label>
    <link:label id="lab_cik0001563922_SettlementAgreementCreditForBalanceDueToVendorAmount_documentation_en-US" xlink:label="lab_cik0001563922_SettlementAgreementCreditForBalanceDueToVendorAmount" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Settlement Agreement, Credit For Balance Due to Vendor, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SettlementAgreementCreditForBalanceDueToVendorAmount" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SettlementAgreementCreditForBalanceDueToVendorAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SettlementAgreementCreditForBalanceDueToVendorAmount" xlink:to="lab_cik0001563922_SettlementAgreementCreditForBalanceDueToVendorAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentMember_019f7115-c5e8-757d-bb23-9cc60a126efe_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Plant and equipment</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentMember_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentMember" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ProceedsFromDerivativeInstrumentOperatingActivities_019f7115-c76d-7640-a49a-0ca3c3ba5e69_terseLabel_en-US" xlink:label="lab_cik0001563922_ProceedsFromDerivativeInstrumentOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds received from derivative instruments, cash</link:label>
    <link:label id="lab_cik0001563922_ProceedsFromDerivativeInstrumentOperatingActivities_label_en-US" xlink:label="lab_cik0001563922_ProceedsFromDerivativeInstrumentOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds From Derivative Instrument, Operating Activities</link:label>
    <link:label id="lab_cik0001563922_ProceedsFromDerivativeInstrumentOperatingActivities_documentation_en-US" xlink:label="lab_cik0001563922_ProceedsFromDerivativeInstrumentOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Proceeds From Derivative Instrument, Operating Activities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ProceedsFromDerivativeInstrumentOperatingActivities" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ProceedsFromDerivativeInstrumentOperatingActivities"/>
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    <link:label id="lab_cik0001563922_OperatingLeasePaymentsMeasurementOfLeaseLiabilities_019f7115-c6fc-769a-b09d-0526d0491a02_totalLabel_en-US" xlink:label="lab_cik0001563922_OperatingLeasePaymentsMeasurementOfLeaseLiabilities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Cash paid for amounts included in the measurement of lease liabilities</link:label>
    <link:label id="lab_cik0001563922_OperatingLeasePaymentsMeasurementOfLeaseLiabilities_label_en-US" xlink:label="lab_cik0001563922_OperatingLeasePaymentsMeasurementOfLeaseLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Payments, Measurement Of Lease Liabilities</link:label>
    <link:label id="lab_cik0001563922_OperatingLeasePaymentsMeasurementOfLeaseLiabilities_documentation_en-US" xlink:label="lab_cik0001563922_OperatingLeasePaymentsMeasurementOfLeaseLiabilities" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Operating Lease, Payments, Measurement Of Lease Liabilities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OperatingLeasePaymentsMeasurementOfLeaseLiabilities" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OperatingLeasePaymentsMeasurementOfLeaseLiabilities"/>
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    <link:label id="lab_cik0001563922_GreenbackerWindHoldingsIILLCMember_019f7115-c671-7f63-9073-a11a6b4ad07d_terseLabel_en-US" xlink:label="lab_cik0001563922_GreenbackerWindHoldingsIILLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Greenbacker Wind Holdings II LLC</link:label>
    <link:label id="lab_cik0001563922_GreenbackerWindHoldingsIILLCMember_label_en-US" xlink:label="lab_cik0001563922_GreenbackerWindHoldingsIILLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Greenbacker Wind Holdings II LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_GreenbackerWindHoldingsIILLCMember_documentation_en-US" xlink:label="lab_cik0001563922_GreenbackerWindHoldingsIILLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Greenbacker Wind Holdings II LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GreenbackerWindHoldingsIILLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GreenbackerWindHoldingsIILLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GreenbackerWindHoldingsIILLCMember" xlink:to="lab_cik0001563922_GreenbackerWindHoldingsIILLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StockholdersEquityPolicyTextBlock_019f7115-c6fc-7144-83bf-84825831f645_terseLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquityPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distribution Policy</link:label>
    <link:label id="lab_us-gaap_StockholdersEquityPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_StockholdersEquityPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stockholders' Equity, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockholdersEquityPolicyTextBlock" xlink:to="lab_us-gaap_StockholdersEquityPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ProductionCapacityPreOperational_019f7115-c671-79ea-baf2-61000ea0b916_terseLabel_en-US" xlink:label="lab_cik0001563922_ProductionCapacityPreOperational" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Production capacity, pre-operational</link:label>
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    <link:label id="lab_cik0001563922_ProductionCapacityPreOperational_documentation_en-US" xlink:label="lab_cik0001563922_ProductionCapacityPreOperational" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Production Capacity, Pre-Operational</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_019f7115-c671-7506-b7da-45dbdd0ada66_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Accumulated depreciation</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, Accumulated Depreciation and Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree_019f7115-c6fc-7e46-9d13-339218c81475_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2028-2029</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, to be Paid, Rolling Year Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitions_019f7115-c5e8-7974-a485-ace28e4029b4_terseLabel_en-US" xlink:label="lab_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class P-I Share reclassification to permanent equity</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitions_label_en-US" xlink:label="lab_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Stock Issued During Period, Earnout Shares, Acquisitions</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitions_documentation_en-US" xlink:label="lab_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitions" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Temporary Equity, Stock Issued During Period, Earnout Shares, Acquisitions</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitions" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitions"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitions" xlink:to="lab_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitions" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherCommitmentDueAfterFifthYear_019f7115-c76d-79fd-8a35-50685213d9ff_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCommitmentDueAfterFifthYear" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Thereafter</link:label>
    <link:label id="lab_us-gaap_OtherCommitmentDueAfterFifthYear_label_en-US" xlink:label="lab_us-gaap_OtherCommitmentDueAfterFifthYear" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Commitment, to be Paid, after Year Five</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentDueAfterFifthYear" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentDueAfterFifthYear"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCommitmentDueAfterFifthYear" xlink:to="lab_us-gaap_OtherCommitmentDueAfterFifthYear" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f7115-c6fc-7ccc-bdec-a9a4aaf18962_periodStartLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Unvested balance, beginning balance (in shares)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f7115-c6fc-7224-bc2a-62353fd1a945_periodEndLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Unvested balance, ending balance (in shares)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
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    <link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_019f7115-c671-7eb1-bd7e-1250b6151a2b_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Commitments and Contingencies Disclosure [Abstract]</link:label>
    <link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitments and Contingencies Disclosure [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AdministrativeFeeMember_019f7115-c671-78ea-83b4-9798d51cc8a2_terseLabel_en-US" xlink:label="lab_cik0001563922_AdministrativeFeeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Administrative fees</link:label>
    <link:label id="lab_cik0001563922_AdministrativeFeeMember_019f7115-c671-703e-8912-d91077f6215d_verboseLabel_en-US" xlink:label="lab_cik0001563922_AdministrativeFeeMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Administrative fee receivable</link:label>
    <link:label id="lab_cik0001563922_AdministrativeFeeMember_label_en-US" xlink:label="lab_cik0001563922_AdministrativeFeeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Administrative Fee [Member]</link:label>
    <link:label id="lab_cik0001563922_AdministrativeFeeMember_documentation_en-US" xlink:label="lab_cik0001563922_AdministrativeFeeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Administrative Fee</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AdministrativeFeeMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AdministrativeFeeMember"/>
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    <link:label id="lab_us-gaap_LitigationSettlementGain_019f7115-c554-7258-bb8b-8fb54c5ec625_terseLabel_en-US" xlink:label="lab_us-gaap_LitigationSettlementGain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Litigation settlement, gain</link:label>
    <link:label id="lab_us-gaap_LitigationSettlementGain_label_en-US" xlink:label="lab_us-gaap_LitigationSettlementGain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Litigation Settlement, Gain</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementGain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LitigationSettlementGain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LitigationSettlementGain" xlink:to="lab_us-gaap_LitigationSettlementGain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesGross_019f7115-c5e8-7665-b4a3-200052bd573a_negatedLabel_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesGross" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Gross carrying amount</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesGross_label_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities, Gross</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesGross_documentation_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesGross" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities, Gross</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesGross" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OutOfMarketContractsIntangibleLiabilitiesGross"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesGross" xlink:to="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesGross" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_019f7115-c6fc-78f8-9b2f-e6edfa4e0441_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash provided by (used in) operating activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash Provided by (Used in) Operating Activity, Including Discontinued Operation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ConstructionRevolvingAndTermLoansMember_019f7115-c671-7b91-a98a-a6170488e83c_terseLabel_en-US" xlink:label="lab_cik0001563922_ConstructionRevolvingAndTermLoansMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Construction, Revolving and Term Loans</link:label>
    <link:label id="lab_cik0001563922_ConstructionRevolvingAndTermLoansMember_label_en-US" xlink:label="lab_cik0001563922_ConstructionRevolvingAndTermLoansMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Construction, Revolving And Term Loans [Member]</link:label>
    <link:label id="lab_cik0001563922_ConstructionRevolvingAndTermLoansMember_documentation_en-US" xlink:label="lab_cik0001563922_ConstructionRevolvingAndTermLoansMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Construction, Revolving And Term Loans</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ConstructionRevolvingAndTermLoansMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ConstructionRevolvingAndTermLoansMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ConstructionRevolvingAndTermLoansMember" xlink:to="lab_cik0001563922_ConstructionRevolvingAndTermLoansMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromInsuranceSettlementInvestingActivities_019f7115-c554-7d2e-bf70-1fc66b6188ca_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromInsuranceSettlementInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Insurance proceeds for damaged equipment</link:label>
    <link:label id="lab_us-gaap_ProceedsFromInsuranceSettlementInvestingActivities_label_en-US" xlink:label="lab_us-gaap_ProceedsFromInsuranceSettlementInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from Insurance Settlement, Investing Activities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromInsuranceSettlementInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromInsuranceSettlementInvestingActivities"/>
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    <link:label id="lab_cik0001563922_GBSolarTE2020ManagerLLCMember_019f7115-c671-7f68-99da-dfd33e8828b1_terseLabel_en-US" xlink:label="lab_cik0001563922_GBSolarTE2020ManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GB Solar TE 2020 Manager LLC</link:label>
    <link:label id="lab_cik0001563922_GBSolarTE2020ManagerLLCMember_label_en-US" xlink:label="lab_cik0001563922_GBSolarTE2020ManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">GB Solar TE 2020 Manager LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_GBSolarTE2020ManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_GBSolarTE2020ManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">GB Solar TE 2020 Manager LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GBSolarTE2020ManagerLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GBSolarTE2020ManagerLLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GBSolarTE2020ManagerLLCMember" xlink:to="lab_cik0001563922_GBSolarTE2020ManagerLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract_label_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Method Investments and Joint Ventures [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract"/>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife_019f7115-c6fc-7962-9742-0a4714e9a139_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Useful Lives (Years)</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment, Useful Life</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
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    <link:label id="lab_us-gaap_PreferredStockParOrStatedValuePerShare_019f7115-c671-7e61-a38f-e7dc4bf4f562_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Preferred shares, par value (in dollars per share)</link:label>
    <link:label id="lab_us-gaap_PreferredStockParOrStatedValuePerShare_label_en-US" xlink:label="lab_us-gaap_PreferredStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred Stock, Par or Stated Value Per Share</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockParOrStatedValuePerShare" xlink:to="lab_us-gaap_PreferredStockParOrStatedValuePerShare" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligation_019f7115-c671-7b3c-9f09-2b6ec88c3230_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Present value of lease payments</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligation_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligation_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligation" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionFinancingObligation" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionFinancingObligation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionFinancingObligation" xlink:to="lab_cik0001563922_SaleLeasebackTransactionFinancingObligation" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SubsequentEventMember_019f7115-c5e8-7448-8782-59d1123a5975_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Event</link:label>
    <link:label id="lab_us-gaap_SubsequentEventMember_label_en-US" xlink:label="lab_us-gaap_SubsequentEventMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventMember" xlink:to="lab_us-gaap_SubsequentEventMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ManagementServiceBaseMember_019f7115-c5e8-7fcd-8e7b-82a092c9ac39_terseLabel_en-US" xlink:label="lab_us-gaap_ManagementServiceBaseMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Management fees</link:label>
    <link:label id="lab_us-gaap_ManagementServiceBaseMember_019f7115-c5e8-7187-a74f-5a5ba3a17f18_verboseLabel_en-US" xlink:label="lab_us-gaap_ManagementServiceBaseMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Management fees receivable</link:label>
    <link:label id="lab_us-gaap_ManagementServiceBaseMember_label_en-US" xlink:label="lab_us-gaap_ManagementServiceBaseMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Management Service, Base [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementServiceBaseMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManagementServiceBaseMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ManagementServiceBaseMember" xlink:to="lab_us-gaap_ManagementServiceBaseMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongtermDebtTypeAxis_019f7115-c5e8-7734-bfee-90c959cd4507_terseLabel_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-term Debt, Type [Axis]</link:label>
    <link:label id="lab_us-gaap_LongtermDebtTypeAxis_label_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongtermDebtTypeAxis" xlink:to="lab_us-gaap_LongtermDebtTypeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_Depreciation_019f7115-c5e8-7d94-b8ca-ecae5577ad4c_terseLabel_en-US" xlink:label="lab_us-gaap_Depreciation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Depreciation expense</link:label>
    <link:label id="lab_us-gaap_Depreciation_label_en-US" xlink:label="lab_us-gaap_Depreciation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Depreciation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Depreciation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Depreciation" xlink:to="lab_us-gaap_Depreciation" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_019f7115-c5e8-7a4f-b8b4-fee013ac2aca_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Weighted average shares outstanding</link:label>
    <link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_label_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Weighted Average Number of Shares Outstanding, Basic [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract" xlink:to="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilities_019f7115-c554-74c0-94cc-98bc956af41d_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accrued expenses</link:label>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilities_label_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Accrued Liabilities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilities" xlink:to="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementEquityComponentsAxis_019f7115-c6fc-7d7a-a724-7d9164fb2e1d_terseLabel_en-US" xlink:label="lab_us-gaap_StatementEquityComponentsAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Equity Components [Axis]</link:label>
    <link:label id="lab_us-gaap_StatementEquityComponentsAxis_label_en-US" xlink:label="lab_us-gaap_StatementEquityComponentsAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Components [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementEquityComponentsAxis" xlink:to="lab_us-gaap_StatementEquityComponentsAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentLineItems_019f7115-c555-78aa-87d4-1f1371cb21a6_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Line Items]</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentLineItems_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MinorityInterestChangeInRedemptionValue_019f7115-c5e8-7c0b-acdb-84666bcd0ae5_terseLabel_en-US" xlink:label="lab_us-gaap_MinorityInterestChangeInRedemptionValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Redemption value adjustment for redeemable noncontrolling interest</link:label>
    <link:label id="lab_us-gaap_MinorityInterestChangeInRedemptionValue_label_en-US" xlink:label="lab_us-gaap_MinorityInterestChangeInRedemptionValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Change in Redemption Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestChangeInRedemptionValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestChangeInRedemptionValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MinorityInterestChangeInRedemptionValue" xlink:to="lab_us-gaap_MinorityInterestChangeInRedemptionValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StandbyLettersOfCreditMember_019f7115-c555-7b34-949c-38f9db697730_terseLabel_en-US" xlink:label="lab_us-gaap_StandbyLettersOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Standby Letters of Credit</link:label>
    <link:label id="lab_us-gaap_StandbyLettersOfCreditMember_label_en-US" xlink:label="lab_us-gaap_StandbyLettersOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Standby Letters of Credit [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StandbyLettersOfCreditMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StandbyLettersOfCreditMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StandbyLettersOfCreditMember" xlink:to="lab_us-gaap_StandbyLettersOfCreditMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesDuringAny12MonthPeriod_019f7115-c6fc-7c70-a6b0-5bd17ab7dcc8_terseLabel_en-US" xlink:label="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesDuringAny12MonthPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock repurchase limit, percentage of weighted average number of shares during any 12-month period</link:label>
    <link:label id="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesDuringAny12MonthPeriod_label_en-US" xlink:label="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesDuringAny12MonthPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Repurchase Program, Stock Repurchase Limit, Percentage Of Weighted Average Number Of Shares During Any 12-Month Period</link:label>
    <link:label id="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesDuringAny12MonthPeriod_documentation_en-US" xlink:label="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesDuringAny12MonthPeriod" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Stock Repurchase Program, Stock Repurchase Limit, Percentage Of Weighted Average Number Of Shares During Any 12-Month Period</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesDuringAny12MonthPeriod" xlink:href="cik0001563922-20260810.xsd#cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesDuringAny12MonthPeriod"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesDuringAny12MonthPeriod" xlink:to="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesDuringAny12MonthPeriod" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherCommitmentDueInNextTwelveMonths_019f7115-c76d-7338-92e6-0a4c8cf6c061_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCommitmentDueInNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026-2027</link:label>
    <link:label id="lab_us-gaap_OtherCommitmentDueInNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_OtherCommitmentDueInNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Commitment, to be Paid, Year One</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentDueInNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentDueInNextTwelveMonths"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCommitmentDueInNextTwelveMonths" xlink:to="lab_us-gaap_OtherCommitmentDueInNextTwelveMonths" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NumberOfReportableSegments_019f7115-c6fc-7783-b77a-290a9d92dbb7_terseLabel_en-US" xlink:label="lab_us-gaap_NumberOfReportableSegments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of reportable segments</link:label>
    <link:label id="lab_us-gaap_NumberOfReportableSegments_label_en-US" xlink:label="lab_us-gaap_NumberOfReportableSegments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number of Reportable Segments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NumberOfReportableSegments" xlink:to="lab_us-gaap_NumberOfReportableSegments" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_BaseManagementFeePayableAnnualRate_019f7115-c671-7d03-9939-8cb2cd270ad3_terseLabel_en-US" xlink:label="lab_cik0001563922_BaseManagementFeePayableAnnualRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Base management fee payable, annual rate (percent)</link:label>
    <link:label id="lab_cik0001563922_BaseManagementFeePayableAnnualRate_label_en-US" xlink:label="lab_cik0001563922_BaseManagementFeePayableAnnualRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Base Management Fee Payable, Annual Rate</link:label>
    <link:label id="lab_cik0001563922_BaseManagementFeePayableAnnualRate_documentation_en-US" xlink:label="lab_cik0001563922_BaseManagementFeePayableAnnualRate" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Base management fee payable to GCM, annual rate, calculated at an annual rate of gross assets (including amounts borrowed).</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_BaseManagementFeePayableAnnualRate" xlink:href="cik0001563922-20260810.xsd#cik0001563922_BaseManagementFeePayableAnnualRate"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_BaseManagementFeePayableAnnualRate" xlink:to="lab_cik0001563922_BaseManagementFeePayableAnnualRate" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GuaranteeOfTaxCreditRecaptureMember_019f7115-c6fc-7baf-8e15-f72f5b4f035d_terseLabel_en-US" xlink:label="lab_cik0001563922_GuaranteeOfTaxCreditRecaptureMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Guarantee of Tax Credit Recapture</link:label>
    <link:label id="lab_cik0001563922_GuaranteeOfTaxCreditRecaptureMember_label_en-US" xlink:label="lab_cik0001563922_GuaranteeOfTaxCreditRecaptureMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Guarantee Of Tax Credit Recapture [Member]</link:label>
    <link:label id="lab_cik0001563922_GuaranteeOfTaxCreditRecaptureMember_documentation_en-US" xlink:label="lab_cik0001563922_GuaranteeOfTaxCreditRecaptureMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Guarantee Of Tax Credit Recapture</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GuaranteeOfTaxCreditRecaptureMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GuaranteeOfTaxCreditRecaptureMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GuaranteeOfTaxCreditRecaptureMember" xlink:to="lab_cik0001563922_GuaranteeOfTaxCreditRecaptureMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherRestructuringCosts_019f7115-c671-7cc3-854f-73b896eddb49_terseLabel_en-US" xlink:label="lab_us-gaap_OtherRestructuringCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other related costs</link:label>
    <link:label id="lab_us-gaap_OtherRestructuringCosts_label_en-US" xlink:label="lab_us-gaap_OtherRestructuringCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Restructuring Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherRestructuringCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherRestructuringCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherRestructuringCosts" xlink:to="lab_us-gaap_OtherRestructuringCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_VariableInterestEntityDisclosureTextBlock_019f7115-c5e8-7bf3-a065-79f993117636_terseLabel_en-US" xlink:label="lab_us-gaap_VariableInterestEntityDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Interest Entities</link:label>
    <link:label id="lab_us-gaap_VariableInterestEntityDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_VariableInterestEntityDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entity Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VariableInterestEntityDisclosureTextBlock" xlink:to="lab_us-gaap_VariableInterestEntityDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeasePrincipalPayments_019f7115-c6fc-737d-b2a9-42b9ea4b6ede_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeasePrincipalPayments" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Financing cash flows from finance leases</link:label>
    <link:label id="lab_us-gaap_FinanceLeasePrincipalPayments_label_en-US" xlink:label="lab_us-gaap_FinanceLeasePrincipalPayments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Principal Payments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeasePrincipalPayments" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeasePrincipalPayments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeasePrincipalPayments" xlink:to="lab_us-gaap_FinanceLeasePrincipalPayments" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearThree_019f7115-c6fc-7c90-a642-2aca3c93eef3_terseLabel_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2028-2029</link:label>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearThree_label_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets And Liabilities, Net, Expected Amortization, Rolling Year Three</link:label>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearThree_documentation_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets And Liabilities, Net, Expected Amortization, Rolling Year Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearThree" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearThree"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearThree" xlink:to="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearThree" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AmortizationOfFiniteLivedIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilities_019f7115-c5e8-70fe-bf06-9a562db7548c_terseLabel_en-US" xlink:label="lab_cik0001563922_AmortizationOfFiniteLivedIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amortization expense on channel partner relationships and trademark intangible assets, net</link:label>
    <link:label id="lab_cik0001563922_AmortizationOfFiniteLivedIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilities_label_en-US" xlink:label="lab_cik0001563922_AmortizationOfFiniteLivedIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amortization Of Finite-Lived Intangible Assets And Out-of-Market Contracts, Intangible Liabilities</link:label>
    <link:label id="lab_cik0001563922_AmortizationOfFiniteLivedIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilities_documentation_en-US" xlink:label="lab_cik0001563922_AmortizationOfFiniteLivedIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilities" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amortization Of Finite-Lived Intangible Assets And Out-of-Market Contracts, Intangible Liabilities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AmortizationOfFiniteLivedIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilities" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AmortizationOfFiniteLivedIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_AmortizationOfFiniteLivedIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilities" xlink:to="lab_cik0001563922_AmortizationOfFiniteLivedIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilities" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_MeasurementInputAnnualizedRevenueVolatilityMember_019f7115-c671-71c7-8df9-f3f816a3ffc4_terseLabel_en-US" xlink:label="lab_cik0001563922_MeasurementInputAnnualizedRevenueVolatilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Annualized Revenue Volatility</link:label>
    <link:label id="lab_cik0001563922_MeasurementInputAnnualizedRevenueVolatilityMember_label_en-US" xlink:label="lab_cik0001563922_MeasurementInputAnnualizedRevenueVolatilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input, Annualized Revenue Volatility [Member]</link:label>
    <link:label id="lab_cik0001563922_MeasurementInputAnnualizedRevenueVolatilityMember_documentation_en-US" xlink:label="lab_cik0001563922_MeasurementInputAnnualizedRevenueVolatilityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Measurement Input, Annualized Revenue Volatility</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_MeasurementInputAnnualizedRevenueVolatilityMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_MeasurementInputAnnualizedRevenueVolatilityMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_MeasurementInputAnnualizedRevenueVolatilityMember" xlink:to="lab_cik0001563922_MeasurementInputAnnualizedRevenueVolatilityMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseImpairmentLoss_019f7115-c671-75d6-940c-f0785fd4f221_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impairment loss</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseImpairmentLoss_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Impairment Loss</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseImpairmentLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseImpairmentLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseImpairmentLoss" xlink:to="lab_us-gaap_OperatingLeaseImpairmentLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsFairValueAssumptionsGrantDateFairValue_019f7115-c5e8-7084-908b-d8e99189284c_terseLabel_en-US" xlink:label="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsFairValueAssumptionsGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Grant date fair value</link:label>
    <link:label id="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsFairValueAssumptionsGrantDateFairValue_label_en-US" xlink:label="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsFairValueAssumptionsGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Fair Value Assumptions, Grant Date Fair Value</link:label>
    <link:label id="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsFairValueAssumptionsGrantDateFairValue_documentation_en-US" xlink:label="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsFairValueAssumptionsGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Fair Value Assumptions, Grant Date Fair Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsFairValueAssumptionsGrantDateFairValue" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsFairValueAssumptionsGrantDateFairValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsFairValueAssumptionsGrantDateFairValue" xlink:to="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsFairValueAssumptionsGrantDateFairValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent_019f7115-c5e8-7eff-87dc-28adc32d5dc0_totalLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total noncurrent assets</link:label>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent_label_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Assets, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent" xlink:to="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DividendsCommonStock_019f7115-c671-7ac6-9d68-d97b5f9abd5a_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DividendsCommonStock" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Shareholder distributions</link:label>
    <link:label id="lab_us-gaap_DividendsCommonStock_label_en-US" xlink:label="lab_us-gaap_DividendsCommonStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dividends, Common Stock</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsCommonStock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DividendsCommonStock" xlink:to="lab_us-gaap_DividendsCommonStock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesCurrent_019f7115-c5e8-7582-b267-2cfd405b60aa_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total current liabilities</link:label>
    <link:label id="lab_us-gaap_LiabilitiesCurrent_label_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Liabilities, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesCurrent" xlink:to="lab_us-gaap_LiabilitiesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GRPIIBorealisSolarLLCMember_019f7115-c671-71a6-8329-9797e8e8d070_terseLabel_en-US" xlink:label="lab_cik0001563922_GRPIIBorealisSolarLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GRP II Borealis Solar LLC</link:label>
    <link:label id="lab_cik0001563922_GRPIIBorealisSolarLLCMember_label_en-US" xlink:label="lab_cik0001563922_GRPIIBorealisSolarLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">GRP II Borealis Solar LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_GRPIIBorealisSolarLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_GRPIIBorealisSolarLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">GRP II Borealis Solar LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GRPIIBorealisSolarLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GRPIIBorealisSolarLLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GRPIIBorealisSolarLLCMember" xlink:to="lab_cik0001563922_GRPIIBorealisSolarLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain_019f7115-c671-737f-8472-e5cbb79a47c5_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-Term Purchase Commitment, Category of Item Purchased [Domain]</link:label>
    <link:label id="lab_us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain_label_en-US" xlink:label="lab_us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Purchase Commitment, Category of Item Purchased [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain" xlink:to="lab_us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PaymentsForDeferredShareholderServicingFees_019f7115-c671-799f-94d3-718b3ca75d63_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_PaymentsForDeferredShareholderServicingFees" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Deferred shareholder servicing fees</link:label>
    <link:label id="lab_cik0001563922_PaymentsForDeferredShareholderServicingFees_label_en-US" xlink:label="lab_cik0001563922_PaymentsForDeferredShareholderServicingFees" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments For Deferred Shareholder Servicing Fees</link:label>
    <link:label id="lab_cik0001563922_PaymentsForDeferredShareholderServicingFees_documentation_en-US" xlink:label="lab_cik0001563922_PaymentsForDeferredShareholderServicingFees" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Payments For Deferred Shareholder Servicing Fees</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PaymentsForDeferredShareholderServicingFees" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PaymentsForDeferredShareholderServicingFees"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PaymentsForDeferredShareholderServicingFees" xlink:to="lab_cik0001563922_PaymentsForDeferredShareholderServicingFees" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioOneMember_019f7115-c554-7a9b-a78c-3cf491d2b369_terseLabel_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Fee Arrangement, Scenario One</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioOneMember_label_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Fee Arrangement, Scenario One [Member]</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioOneMember_documentation_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioOneMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Fee Arrangement, Scenario One</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioOneMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RelatedPartyTransactionFeeArrangementScenarioOneMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioOneMember" xlink:to="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioOneMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_019f7115-c555-7749-b945-4a7b75892a51_totalLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total property, plant and equipment</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ShareRepurchaseProgramTableTextBlock_019f7115-c76d-7e5c-bd32-f95e929698aa_terseLabel_en-US" xlink:label="lab_cik0001563922_ShareRepurchaseProgramTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Quarterly Share Repurchase Limits</link:label>
    <link:label id="lab_cik0001563922_ShareRepurchaseProgramTableTextBlock_label_en-US" xlink:label="lab_cik0001563922_ShareRepurchaseProgramTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share Repurchase Program [Table Text Block]</link:label>
    <link:label id="lab_cik0001563922_ShareRepurchaseProgramTableTextBlock_documentation_en-US" xlink:label="lab_cik0001563922_ShareRepurchaseProgramTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Share Repurchase Program</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ShareRepurchaseProgramTableTextBlock" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ShareRepurchaseProgramTableTextBlock"/>
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    <link:label id="lab_us-gaap_IncomeTaxAuthorityDomain_019f7115-c555-74bc-af84-be6f9532bd9a_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income Tax Jurisdiction [Domain]</link:label>
    <link:label id="lab_us-gaap_IncomeTaxAuthorityDomain_label_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax Jurisdiction [Domain]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain" xlink:to="lab_us-gaap_IncomeTaxAuthorityDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfAssetRetirementObligationsTableTextBlock_019f7115-c6fc-712b-9829-28de36b66ee5_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfAssetRetirementObligationsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Asset Retirement Obligations</link:label>
    <link:label id="lab_us-gaap_ScheduleOfAssetRetirementObligationsTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfAssetRetirementObligationsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Asset Retirement Obligations [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAssetRetirementObligationsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAssetRetirementObligationsTableTextBlock"/>
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    <link:label id="lab_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_019f7115-c6fc-7a30-b6f4-9c8132d39e14_terseLabel_en-US" xlink:label="lab_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">ROU assets obtained in exchange for new and modified finance lease liabilities</link:label>
    <link:label id="lab_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_label_en-US" xlink:label="lab_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Right-of-Use Asset Obtained in Exchange for Finance Lease Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability"/>
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    <link:label id="lab_cik0001563922_TrilliumManagerLLCMember_019f7115-c6fc-77c3-a518-bcaef9945975_terseLabel_en-US" xlink:label="lab_cik0001563922_TrilliumManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Trillium Manager LLC</link:label>
    <link:label id="lab_cik0001563922_TrilliumManagerLLCMember_label_en-US" xlink:label="lab_cik0001563922_TrilliumManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Trillium Manager LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_TrilliumManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_TrilliumManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Trillium Manager LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TrilliumManagerLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TrilliumManagerLLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_TrilliumManagerLLCMember" xlink:to="lab_cik0001563922_TrilliumManagerLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromMinorityShareholders_019f7115-c671-7465-82ac-6d662450d3c8_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromMinorityShareholders" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contributions from noncontrolling interests, net</link:label>
    <link:label id="lab_us-gaap_ProceedsFromMinorityShareholders_019f7115-c671-7bf5-a1fd-5bb2ff7e1045_netLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromMinorityShareholders" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xml:lang="en-US">Contributions from Tax Equity Investors</link:label>
    <link:label id="lab_us-gaap_ProceedsFromMinorityShareholders_label_en-US" xlink:label="lab_us-gaap_ProceedsFromMinorityShareholders" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from Noncontrolling Interests</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromMinorityShareholders" xlink:to="lab_us-gaap_ProceedsFromMinorityShareholders" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount_019f7115-c671-78a6-92eb-59ad9f873473_terseLabel_en-US" xlink:label="lab_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Maximum exposure to loss</link:label>
    <link:label id="lab_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount_label_en-US" xlink:label="lab_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount" xlink:to="lab_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_019f7115-c6fc-71f4-9d98-35a91ac51e13_terseLabel_en-US" xlink:label="lab_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Ownership percentage held by noncontrolling owners</link:label>
    <link:label id="lab_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_label_en-US" xlink:label="lab_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsidiary, Ownership Percentage, Noncontrolling Owner</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners" xlink:to="lab_us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RepaymentsOfLongTermDebt_019f7115-c6fc-73c9-a89f-570f3ab927b4_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfLongTermDebt" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Payments on borrowings</link:label>
    <link:label id="lab_us-gaap_RepaymentsOfLongTermDebt_label_en-US" xlink:label="lab_us-gaap_RepaymentsOfLongTermDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Repayments of Long-Term Debt</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RepaymentsOfLongTermDebt" xlink:to="lab_us-gaap_RepaymentsOfLongTermDebt" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodShares_019f7115-c671-7482-a3a2-995163d4c259_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodShares" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Repurchases of common shares (in shares)</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodShares_label_en-US" xlink:label="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Stock Repurchased During Period, Shares</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodShares_documentation_en-US" xlink:label="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodShares" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Temporary Equity, Stock Repurchased During Period, Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodShares" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodShares"/>
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    <link:label id="lab_cik0001563922_NetFeeRelatedEarningsReceivablePercent_019f7115-c5e8-7883-a0d6-48d838ea2dfd_terseLabel_en-US" xlink:label="lab_cik0001563922_NetFeeRelatedEarningsReceivablePercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fee related earnings receivable (percent)</link:label>
    <link:label id="lab_cik0001563922_NetFeeRelatedEarningsReceivablePercent_label_en-US" xlink:label="lab_cik0001563922_NetFeeRelatedEarningsReceivablePercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Fee Related Earnings Receivable, Percent</link:label>
    <link:label id="lab_cik0001563922_NetFeeRelatedEarningsReceivablePercent_documentation_en-US" xlink:label="lab_cik0001563922_NetFeeRelatedEarningsReceivablePercent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Net Fee Related Earnings Receivable, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NetFeeRelatedEarningsReceivablePercent" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NetFeeRelatedEarningsReceivablePercent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NetFeeRelatedEarningsReceivablePercent" xlink:to="lab_cik0001563922_NetFeeRelatedEarningsReceivablePercent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFive_019f7115-c6fc-7152-ae65-16847b29cbe3_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2030-2031</link:label>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFive_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Maturities, Repayments of Principal in Rolling Year Five</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFive"/>
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    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiability_019f7115-c5e8-7d8b-8087-079fc6a8511a_periodStartLabel_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiability" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Beginning balance</link:label>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiability_019f7115-c5e8-7f11-a715-1ab87e95d5bf_periodEndLabel_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiability" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Ending balance</link:label>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiability_label_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Net Asset (Liability)</link:label>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiability_documentation_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiability" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Net Asset (Liability)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiability" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiability"/>
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    <link:label id="lab_cik0001563922_ClassPASharesMember_019f7115-c671-7204-af40-57e7ec6dd8fc_terseLabel_en-US" xlink:label="lab_cik0001563922_ClassPASharesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class P-A</link:label>
    <link:label id="lab_cik0001563922_ClassPASharesMember_label_en-US" xlink:label="lab_cik0001563922_ClassPASharesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class P-A Shares [Member]</link:label>
    <link:label id="lab_cik0001563922_ClassPASharesMember_documentation_en-US" xlink:label="lab_cik0001563922_ClassPASharesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Class P-A Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ClassPASharesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ClassPASharesMember"/>
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    <link:label id="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersOperationsBasicAbstract_019f7115-c6fc-7880-8738-eac25929bd19_terseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersOperationsBasicAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Basic and diluted:</link:label>
    <link:label id="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersOperationsBasicAbstract_label_en-US" xlink:label="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersOperationsBasicAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss) Available to Common Stockholders, Basic, Operations [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersOperationsBasicAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersOperationsBasicAbstract"/>
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    <link:label id="lab_us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost_019f7115-c6fc-7028-bba6-aef057af83f8_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based compensation</link:label>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost_label_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-Based Payment Arrangement, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost"/>
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    <link:label id="lab_us-gaap_OtherCommitmentDueInFourthYear_019f7115-c76d-7ab5-8e9c-fcf23d8ca0e8_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCommitmentDueInFourthYear" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2029-2030</link:label>
    <link:label id="lab_us-gaap_OtherCommitmentDueInFourthYear_label_en-US" xlink:label="lab_us-gaap_OtherCommitmentDueInFourthYear" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Commitment, to be Paid, Year Four</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentDueInFourthYear" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentDueInFourthYear"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCommitmentDueInFourthYear" xlink:to="lab_us-gaap_OtherCommitmentDueInFourthYear" xlink:type="arc" order="1"/>
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    <link:label id="lab_us-gaap_DisaggregationOfRevenueTable_label_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disaggregation of Revenue [Table]</link:label>
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    <link:label id="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_019f7115-c5e8-7d8d-955d-cf06a75e609a_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net operating and other losses</link:label>
    <link:label id="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Operating Loss Carryforwards</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards"/>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f7115-c555-7521-882a-69774425c13c_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-Lived Tangible Asset [Axis]</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Lived Tangible Asset [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:type="arc" order="1"/>
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    <link:label id="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporaryShares_label_en-US" xlink:label="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporaryShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Reclassifications From Permanent Equity To Temporary, Shares</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporaryShares_documentation_en-US" xlink:label="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporaryShares" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Temporary Equity, Reclassifications From Permanent Equity To Temporary, Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporaryShares" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporaryShares"/>
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    <link:label id="lab_cik0001563922_ClassPISharesMember_label_en-US" xlink:label="lab_cik0001563922_ClassPISharesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class P-I Shares [Member]</link:label>
    <link:label id="lab_cik0001563922_ClassPISharesMember_documentation_en-US" xlink:label="lab_cik0001563922_ClassPISharesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Class P-I Shares</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ClassPISharesMember" xlink:to="lab_cik0001563922_ClassPISharesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_OwnershipDomain_019f7115-c5e8-774d-a4bc-468721bb8a48_terseLabel_en-US" xlink:label="lab_srt_OwnershipDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Ownership [Domain]</link:label>
    <link:label id="lab_srt_OwnershipDomain_label_en-US" xlink:label="lab_srt_OwnershipDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Ownership [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_OwnershipDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_OwnershipDomain" xlink:to="lab_srt_OwnershipDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ImpairmentLongLivedAssetHeldForUseNet_019f7115-c5e8-74e2-9e9c-ad97a0be7d6a_terseLabel_en-US" xlink:label="lab_cik0001563922_ImpairmentLongLivedAssetHeldForUseNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impairment of long-lived assets, net</link:label>
    <link:label id="lab_cik0001563922_ImpairmentLongLivedAssetHeldForUseNet_label_en-US" xlink:label="lab_cik0001563922_ImpairmentLongLivedAssetHeldForUseNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Impairment, Long-Lived Asset, Held-for-Use, Net</link:label>
    <link:label id="lab_cik0001563922_ImpairmentLongLivedAssetHeldForUseNet_documentation_en-US" xlink:label="lab_cik0001563922_ImpairmentLongLivedAssetHeldForUseNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Impairment, Long-Lived Asset, Held-for-Use, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ImpairmentLongLivedAssetHeldForUseNet" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ImpairmentLongLivedAssetHeldForUseNet"/>
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    <link:label id="lab_cik0001563922_ConicManagerLLCMember_019f7115-c671-7c34-be93-7e053f6450ab_terseLabel_en-US" xlink:label="lab_cik0001563922_ConicManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Conic Manager LLC</link:label>
    <link:label id="lab_cik0001563922_ConicManagerLLCMember_label_en-US" xlink:label="lab_cik0001563922_ConicManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Conic Manager LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_ConicManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_ConicManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Conic Manager LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ConicManagerLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ConicManagerLLCMember"/>
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    <link:label id="lab_us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest_019f7115-c6fc-7026-8f9c-9cbfb1b978c8_terseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Less: Net loss attributable to noncontrolling interests</link:label>
    <link:label id="lab_us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest"/>
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    <link:label id="lab_us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization_019f7115-c555-7f76-825a-9363c3cd29bd_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Accumulated depreciation</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization"/>
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    <link:label id="lab_us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_019f7115-c555-7502-8940-fbdadfd93a10_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Goodwill</link:label>
    <link:label id="lab_us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_label_en-US" xlink:label="lab_us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy"/>
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    <link:label id="lab_us-gaap_ScheduleOfReceivablesWithImputedInterestTextBlock_019f7115-c6fc-7bd3-92c9-e05b9fe75f84_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfReceivablesWithImputedInterestTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Notes Receivable</link:label>
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    <link:label id="lab_us-gaap_OtherAssetsNoncurrent_019f7115-c5e8-7d8e-bd13-35b5f4d5d3cc_terseLabel_en-US" xlink:label="lab_us-gaap_OtherAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other noncurrent assets</link:label>
    <link:label id="lab_us-gaap_OtherAssetsNoncurrent_label_en-US" xlink:label="lab_us-gaap_OtherAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Assets, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
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    <link:label id="lab_srt_NameOfMajorCustomerDomain_019f7115-c5e8-75f1-b77f-c47fd868b808_terseLabel_en-US" xlink:label="lab_srt_NameOfMajorCustomerDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Customer [Domain]</link:label>
    <link:label id="lab_srt_NameOfMajorCustomerDomain_label_en-US" xlink:label="lab_srt_NameOfMajorCustomerDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Customer [Domain]</link:label>
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    <link:label id="lab_us-gaap_AssetRetirementObligation_019f7115-c6fc-7a79-beb6-a30346514a98_periodStartLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligation" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Beginning balance</link:label>
    <link:label id="lab_us-gaap_AssetRetirementObligation_019f7115-c6fc-7ee3-8c23-0c3bcdedd496_periodEndLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligation" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Ending balance</link:label>
    <link:label id="lab_us-gaap_AssetRetirementObligation_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Retirement Obligation</link:label>
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    <link:label id="lab_cik0001563922_PemaquidManagerLLCMember_019f7115-c6fc-7baf-aea7-53e92c8fe065_terseLabel_en-US" xlink:label="lab_cik0001563922_PemaquidManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Pemaquid Manager LLC</link:label>
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    <link:label id="lab_cik0001563922_PemaquidManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_PemaquidManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Pemaquid Manager LLC</link:label>
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    <link:label id="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019f7115-c555-76f8-9eb7-af5326b1f726_negatedPeriodEndLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:role="http://www.xbrl.org/2009/role/negatedPeriodEndLabel" xlink:type="resource" xml:lang="en-US">Ending balance</link:label>
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    <link:label id="lab_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTextBlock_019f7115-c6fc-7be9-812b-f5f43ff8ef45_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Computation of Basic and Diluted Earnings Per Share</link:label>
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    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember_019f7115-c5e8-7550-af98-034052ed789c_terseLabel_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GDEV GP</link:label>
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    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember_documentation_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities GP I, LLC ("GDEV GP")</link:label>
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    <link:label id="lab_cik0001563922_ScheduleOfFiniteLivedIntangibleAssetsAndLiabilitiesNetFutureAmortizationExpenseTableTextBlock_label_en-US" xlink:label="lab_cik0001563922_ScheduleOfFiniteLivedIntangibleAssetsAndLiabilitiesNetFutureAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule Of Finite-Lived Intangible Assets And Liabilities, Net, Future Amortization Expense [Table Text Block]</link:label>
    <link:label id="lab_cik0001563922_ScheduleOfFiniteLivedIntangibleAssetsAndLiabilitiesNetFutureAmortizationExpenseTableTextBlock_documentation_en-US" xlink:label="lab_cik0001563922_ScheduleOfFiniteLivedIntangibleAssetsAndLiabilitiesNetFutureAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Schedule Of Finite-Lived Intangible Assets And Liabilities, Net, Future Amortization Expense</link:label>
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    <link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f7115-c5e8-7581-99a8-3a6b8dea96b4_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table]</link:label>
    <link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table]</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheOneMember_019f7115-c554-7949-b18c-ac0392a8e5cc_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tranche 1 Earnout Shares</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheOneMember_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement, Tranche One [Member]</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock"/>
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    <link:label id="lab_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_019f7115-c5e8-7de2-bc32-c439932e9a4d_periodStartLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Redeemable noncontrolling interests, beginning balance</link:label>
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    <link:label id="lab_cik0001563922_IncreaseDecreaseInWorkingCapital_documentation_en-US" xlink:label="lab_cik0001563922_IncreaseDecreaseInWorkingCapital" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Working Capital</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_IncreaseDecreaseOfDistributionsPayableToNoncontrollingInterests" xlink:href="cik0001563922-20260810.xsd#cik0001563922_IncreaseDecreaseOfDistributionsPayableToNoncontrollingInterests"/>
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    <link:label id="lab_us-gaap_OtherIntangibleAssetsMember_label_en-US" xlink:label="lab_us-gaap_OtherIntangibleAssetsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Intangible Assets [Member]</link:label>
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    <link:label id="lab_us-gaap_LandMember_019f7115-c6fc-7a64-9472-14532b1d1330_terseLabel_en-US" xlink:label="lab_us-gaap_LandMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Land</link:label>
    <link:label id="lab_us-gaap_LandMember_label_en-US" xlink:label="lab_us-gaap_LandMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Land [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LandMember"/>
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    <link:label id="lab_us-gaap_FinancingReceivableAllowanceForCreditLosses_label_en-US" xlink:label="lab_us-gaap_FinancingReceivableAllowanceForCreditLosses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Financing Receivable, Allowance for Credit Loss</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
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    <link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Assets [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract"/>
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    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Award Type [Domain]</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019f7115-c5e8-76b2-b53c-1dc3bffa7ed3_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Dividend yield</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019f7115-c554-72c2-9534-9a2a1853a5ed_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenue recognized on contract liability</link:label>
    <link:label id="lab_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract with Customer, Liability, Revenue Recognized</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:to="lab_us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_InterestRateSwapForwardStartingMember_019f7115-c6fc-7158-8d1b-320327caf5a5_terseLabel_en-US" xlink:label="lab_cik0001563922_InterestRateSwapForwardStartingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest Rate Swap, Forward Starting</link:label>
    <link:label id="lab_cik0001563922_InterestRateSwapForwardStartingMember_label_en-US" xlink:label="lab_cik0001563922_InterestRateSwapForwardStartingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Rate Swap, Forward Starting [Member]</link:label>
    <link:label id="lab_cik0001563922_InterestRateSwapForwardStartingMember_documentation_en-US" xlink:label="lab_cik0001563922_InterestRateSwapForwardStartingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Interest Rate Swap, Forward Starting</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_InterestRateSwapForwardStartingMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_InterestRateSwapForwardStartingMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_InterestRateSwapForwardStartingMember" xlink:to="lab_cik0001563922_InterestRateSwapForwardStartingMember" xlink:type="arc" order="1"/>
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    <link:label id="lab_cik0001563922_ReimbursementAmountReceivablePercentOfCapital_label_en-US" xlink:label="lab_cik0001563922_ReimbursementAmountReceivablePercentOfCapital" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reimbursement Amount Receivable, Percent Of Capital</link:label>
    <link:label id="lab_cik0001563922_ReimbursementAmountReceivablePercentOfCapital_documentation_en-US" xlink:label="lab_cik0001563922_ReimbursementAmountReceivablePercentOfCapital" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Reimbursement Amount Receivable, Percent Of Capital</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ReimbursementAmountReceivablePercentOfCapital" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ReimbursementAmountReceivablePercentOfCapital"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ReimbursementAmountReceivablePercentOfCapital" xlink:to="lab_cik0001563922_ReimbursementAmountReceivablePercentOfCapital" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019f7115-c6fc-7a9c-941b-9d5d433bcf0c_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Change in fair value of contingent consideration</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_019f7115-c6fc-72c1-8835-388c7b9ae3fc_verboseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Change in fair value of contingent consideration</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
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    <link:label id="lab_us-gaap_DistributionsMadeToMemberOrLimitedPartnerByDistributionTypeAxis_019f7115-c554-749f-a4a7-2bda208612d6_terseLabel_en-US" xlink:label="lab_us-gaap_DistributionsMadeToMemberOrLimitedPartnerByDistributionTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distribution Type [Axis]</link:label>
    <link:label id="lab_us-gaap_DistributionsMadeToMemberOrLimitedPartnerByDistributionTypeAxis_label_en-US" xlink:label="lab_us-gaap_DistributionsMadeToMemberOrLimitedPartnerByDistributionTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distribution Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DistributionsMadeToMemberOrLimitedPartnerByDistributionTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DistributionsMadeToMemberOrLimitedPartnerByDistributionTypeAxis"/>
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    <link:label id="lab_us-gaap_RevenuesAbstract_019f7115-c76d-78e8-92fb-8bf745039163_terseLabel_en-US" xlink:label="lab_us-gaap_RevenuesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenue</link:label>
    <link:label id="lab_us-gaap_RevenuesAbstract_label_en-US" xlink:label="lab_us-gaap_RevenuesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenues [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenuesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenuesAbstract" xlink:to="lab_us-gaap_RevenuesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_BaseManagementFeeAggregateNetAssetValueThreshold_019f7115-c671-74a8-b3f6-cc113bc4c9dc_terseLabel_en-US" xlink:label="lab_cik0001563922_BaseManagementFeeAggregateNetAssetValueThreshold" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Aggregate NAV (Class I, Class D, Class T, and Class S shares)</link:label>
    <link:label id="lab_cik0001563922_BaseManagementFeeAggregateNetAssetValueThreshold_label_en-US" xlink:label="lab_cik0001563922_BaseManagementFeeAggregateNetAssetValueThreshold" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Base Management Fee, Aggregate Net Asset Value, Threshold</link:label>
    <link:label id="lab_cik0001563922_BaseManagementFeeAggregateNetAssetValueThreshold_documentation_en-US" xlink:label="lab_cik0001563922_BaseManagementFeeAggregateNetAssetValueThreshold" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Base Management Fee, Aggregate Net Asset Value, Threshold</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_BaseManagementFeeAggregateNetAssetValueThreshold" xlink:href="cik0001563922-20260810.xsd#cik0001563922_BaseManagementFeeAggregateNetAssetValueThreshold"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_BaseManagementFeeAggregateNetAssetValueThreshold" xlink:to="lab_cik0001563922_BaseManagementFeeAggregateNetAssetValueThreshold" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019f7115-c76d-70f2-8208-6e328c30f8fc_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accumulated other comprehensive income</link:label>
    <link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_label_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accumulated Other Comprehensive Income (Loss), Net of Tax</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:to="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentPercent_019f7115-c671-79ba-9050-3c377723542c_terseLabel_en-US" xlink:label="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentPercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Nontaxable parent - GREC LLC treated as a partnership for U.S. tax purposes</link:label>
    <link:label id="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentPercent_label_en-US" xlink:label="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentPercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Nontaxable Parent, Percent</link:label>
    <link:label id="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentPercent_documentation_en-US" xlink:label="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentPercent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Nontaxable Parent, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentPercent" xlink:href="cik0001563922-20260810.xsd#cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentPercent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentPercent" xlink:to="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentPercent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f7115-c5e8-72d1-a6db-6e4667984b60_terseLabel_en-US" xlink:label="lab_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Financial Instruments [Domain]</link:label>
    <link:label id="lab_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_label_en-US" xlink:label="lab_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Financial Instruments [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
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    <link:label id="lab_cik0001563922_SolarEnergySystemsMember_019f7115-c5e8-7ac6-9127-9531c138bbd7_netLabel_en-US" xlink:label="lab_cik0001563922_SolarEnergySystemsMember" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xml:lang="en-US">Solar energy systems</link:label>
    <link:label id="lab_cik0001563922_SolarEnergySystemsMember_label_en-US" xlink:label="lab_cik0001563922_SolarEnergySystemsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Solar Energy Systems [Member]</link:label>
    <link:label id="lab_cik0001563922_SolarEnergySystemsMember_documentation_en-US" xlink:label="lab_cik0001563922_SolarEnergySystemsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Solar Energy Systems</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SolarEnergySystemsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SolarEnergySystemsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SolarEnergySystemsMember" xlink:to="lab_cik0001563922_SolarEnergySystemsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredIncomeTaxLiabilities_019f7115-c6fc-7aa6-8c1f-fc23b057a36b_negatedTotalLabel_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxLiabilities" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xml:lang="en-US">Total deferred tax liabilities</link:label>
    <link:label id="lab_us-gaap_DeferredIncomeTaxLiabilities_label_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Liabilities, Gross</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxLiabilities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredIncomeTaxLiabilities" xlink:to="lab_us-gaap_DeferredIncomeTaxLiabilities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases_019f7115-c5e8-71fa-95ca-c4307013e6c2_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contributions to investees</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases"/>
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    <link:label id="lab_us-gaap_PerformanceSharesMember_019f7115-c5e8-7a3c-8958-befd5e13ddae_terseLabel_en-US" xlink:label="lab_us-gaap_PerformanceSharesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Performance restricted stock units</link:label>
    <link:label id="lab_us-gaap_PerformanceSharesMember_019f7115-c5e8-7c0a-9ec7-c221bd94cf6d_verboseLabel_en-US" xlink:label="lab_us-gaap_PerformanceSharesMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Performance Restricted Share Units</link:label>
    <link:label id="lab_us-gaap_PerformanceSharesMember_label_en-US" xlink:label="lab_us-gaap_PerformanceSharesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Performance Shares [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PerformanceSharesMember"/>
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    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract_019f7115-c5e8-7a02-8458-db04275ff766_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Liabilities</link:label>
    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Liabilities [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:to="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodValue_019f7115-c671-76bb-a8a1-d70ac1692046_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodValue" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Repurchases of common shares</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodValue_label_en-US" xlink:label="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Stock Repurchased During Period, Value</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodValue_documentation_en-US" xlink:label="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodValue" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Temporary Equity, Stock Repurchased During Period, Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodValue" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodValue" xlink:to="lab_cik0001563922_TemporaryEquityStockRepurchasedDuringPeriodValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_019f7115-c554-780f-b019-5813266cd917_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_label_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:to="lab_us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ConstructionInProgressDevelopmentCosts_019f7115-c5e8-7d6e-a65d-465e96cb6fd8_terseLabel_en-US" xlink:label="lab_cik0001563922_ConstructionInProgressDevelopmentCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Development costs</link:label>
    <link:label id="lab_cik0001563922_ConstructionInProgressDevelopmentCosts_label_en-US" xlink:label="lab_cik0001563922_ConstructionInProgressDevelopmentCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Construction In Progress, Development Costs</link:label>
    <link:label id="lab_cik0001563922_ConstructionInProgressDevelopmentCosts_documentation_en-US" xlink:label="lab_cik0001563922_ConstructionInProgressDevelopmentCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Construction In Progress, Development Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ConstructionInProgressDevelopmentCosts" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ConstructionInProgressDevelopmentCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ConstructionInProgressDevelopmentCosts" xlink:to="lab_cik0001563922_ConstructionInProgressDevelopmentCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporaryShares_019f7115-c5e8-7987-9517-ca7342cf58c2_negatedLabel_en-US" xlink:label="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporaryShares" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Reclassification of participating Earnout Shares to temporary equity (in shares)</link:label>
    <link:label id="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporaryShares_label_en-US" xlink:label="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporaryShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reclassifications Of Permanent Equity To Temporary, Shares</link:label>
    <link:label id="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporaryShares_documentation_en-US" xlink:label="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporaryShares" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Reclassifications Of Permanent Equity To Temporary, Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ReclassificationsOfPermanentEquityToTemporaryShares" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ReclassificationsOfPermanentEquityToTemporaryShares"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ReclassificationsOfPermanentEquityToTemporaryShares" xlink:to="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporaryShares" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain_019f7115-c671-7a11-a9b2-577c4e5267a1_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement of Financial Position Location, Activity, Capitalization [Domain]</link:label>
    <link:label id="lab_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain_label_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Financial Position Location, Activity, Capitalization [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain" xlink:to="lab_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PercentageOfMembershipInterestHeld_019f7115-c5e8-7bb2-9543-91d433d7e0af_terseLabel_en-US" xlink:label="lab_cik0001563922_PercentageOfMembershipInterestHeld" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Percentage of membership interest held</link:label>
    <link:label id="lab_cik0001563922_PercentageOfMembershipInterestHeld_label_en-US" xlink:label="lab_cik0001563922_PercentageOfMembershipInterestHeld" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Percentage Of Membership Interest Held</link:label>
    <link:label id="lab_cik0001563922_PercentageOfMembershipInterestHeld_documentation_en-US" xlink:label="lab_cik0001563922_PercentageOfMembershipInterestHeld" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Percentage Of Membership Interest Held</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PercentageOfMembershipInterestHeld" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PercentageOfMembershipInterestHeld"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PercentageOfMembershipInterestHeld" xlink:to="lab_cik0001563922_PercentageOfMembershipInterestHeld" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AmortizationOfDebtIssuanceCostsAndDiscountsLessSaleLeasebackTransaction_019f7115-c5e8-7e13-9acf-c84e7198c9ea_verboseLabel_en-US" xlink:label="lab_cik0001563922_AmortizationOfDebtIssuanceCostsAndDiscountsLessSaleLeasebackTransaction" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Amortization of deferred financing fees and discount</link:label>
    <link:label id="lab_cik0001563922_AmortizationOfDebtIssuanceCostsAndDiscountsLessSaleLeasebackTransaction_label_en-US" xlink:label="lab_cik0001563922_AmortizationOfDebtIssuanceCostsAndDiscountsLessSaleLeasebackTransaction" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amortization Of Debt Issuance Costs And Discounts, Less Sale-Leaseback Transaction</link:label>
    <link:label id="lab_cik0001563922_AmortizationOfDebtIssuanceCostsAndDiscountsLessSaleLeasebackTransaction_documentation_en-US" xlink:label="lab_cik0001563922_AmortizationOfDebtIssuanceCostsAndDiscountsLessSaleLeasebackTransaction" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amortization Of Debt Issuance Costs And Discounts, Less Sale-Leaseback Transaction</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AmortizationOfDebtIssuanceCostsAndDiscountsLessSaleLeasebackTransaction" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AmortizationOfDebtIssuanceCostsAndDiscountsLessSaleLeasebackTransaction"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_AmortizationOfDebtIssuanceCostsAndDiscountsLessSaleLeasebackTransaction" xlink:to="lab_cik0001563922_AmortizationOfDebtIssuanceCostsAndDiscountsLessSaleLeasebackTransaction" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f7115-c6fc-7f01-85f0-105c5df170fb_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets by Major Class [Axis]</link:label>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets by Major Class [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_MinimumMember_019f7115-c6fc-73f0-bfbe-7d96714efca8_terseLabel_en-US" xlink:label="lab_srt_MinimumMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Minimum</link:label>
    <link:label id="lab_srt_MinimumMember_label_en-US" xlink:label="lab_srt_MinimumMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Minimum [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_MinimumMember" xlink:to="lab_srt_MinimumMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GuarantorObligationsMaximumExposureUndiscountedAnnualDecrease_019f7115-c5e8-7f0f-b5b6-5204f64faca3_terseLabel_en-US" xlink:label="lab_cik0001563922_GuarantorObligationsMaximumExposureUndiscountedAnnualDecrease" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Reporting entity involvement, decrease each year, amount</link:label>
    <link:label id="lab_cik0001563922_GuarantorObligationsMaximumExposureUndiscountedAnnualDecrease_label_en-US" xlink:label="lab_cik0001563922_GuarantorObligationsMaximumExposureUndiscountedAnnualDecrease" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Guarantor Obligations, Maximum Exposure, Undiscounted, Annual Decrease</link:label>
    <link:label id="lab_cik0001563922_GuarantorObligationsMaximumExposureUndiscountedAnnualDecrease_documentation_en-US" xlink:label="lab_cik0001563922_GuarantorObligationsMaximumExposureUndiscountedAnnualDecrease" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Guarantor Obligations, Maximum Exposure, Undiscounted, Annual Decrease</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GuarantorObligationsMaximumExposureUndiscountedAnnualDecrease" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GuarantorObligationsMaximumExposureUndiscountedAnnualDecrease"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GuarantorObligationsMaximumExposureUndiscountedAnnualDecrease" xlink:to="lab_cik0001563922_GuarantorObligationsMaximumExposureUndiscountedAnnualDecrease" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNoncurrent_019f7115-c6fc-7cdb-8c3b-5fdaa5946896_terseLabel_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Out-of-market contracts, net</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNoncurrent_label_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities, Noncurrent</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNoncurrent_documentation_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNoncurrent" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNoncurrent" xlink:to="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccountsNotesAndLoansReceivableLineItems_019f7115-c555-7318-a2e5-d6aefb51eb29_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounts, Notes, Loans and Financing Receivable [Line Items]</link:label>
    <link:label id="lab_us-gaap_AccountsNotesAndLoansReceivableLineItems_label_en-US" xlink:label="lab_us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts, Notes, Loans and Financing Receivable [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:to="lab_us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredCostsCurrent_019f7115-c6fc-7a62-a88d-81d6065eff19_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredCostsCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred sales commission, current</link:label>
    <link:label id="lab_us-gaap_DeferredCostsCurrent_label_en-US" xlink:label="lab_us-gaap_DeferredCostsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Costs, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCostsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCostsCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredCostsCurrent" xlink:to="lab_us-gaap_DeferredCostsCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_UnusualOrInfrequentItemNetGainLoss_019f7115-c6fc-76bf-91d1-43ae642febef_terseLabel_en-US" xlink:label="lab_us-gaap_UnusualOrInfrequentItemNetGainLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Damage from infrequent event</link:label>
    <link:label id="lab_us-gaap_UnusualOrInfrequentItemNetGainLoss_label_en-US" xlink:label="lab_us-gaap_UnusualOrInfrequentItemNetGainLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Unusual or Infrequent Item, or Both, Net (Gain) Loss</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnusualOrInfrequentItemNetGainLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnusualOrInfrequentItemNetGainLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UnusualOrInfrequentItemNetGainLoss" xlink:to="lab_us-gaap_UnusualOrInfrequentItemNetGainLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetRetirementObligationDisclosureTextBlock_019f7115-c554-7ceb-9c15-8b0e5ec4da49_terseLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset Retirement Obligations</link:label>
    <link:label id="lab_us-gaap_AssetRetirementObligationDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Retirement Obligation Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetRetirementObligationDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetRetirementObligationDisclosureTextBlock" xlink:to="lab_us-gaap_AssetRetirementObligationDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtDisclosureTextBlock_019f7115-c6fc-7de0-90e6-4d369a501bd9_verboseLabel_en-US" xlink:label="lab_us-gaap_DebtDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Debt</link:label>
    <link:label id="lab_us-gaap_DebtDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_DebtDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtDisclosureTextBlock" xlink:to="lab_us-gaap_DebtDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationPayable_019f7115-c671-7ca4-8da0-4422fb2dd3e5_terseLabel_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationPayable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Liquidation performance participation payable</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationPayable_label_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationPayable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Liquidation Performance Participation Payable</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationPayable_documentation_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationPayable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Liquidation Performance Participation Payable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationPayable" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationPayable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationPayable" xlink:to="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationPayable" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_EnergySalesMember_019f7115-c6fc-7a04-ac7f-3764d4e00dde_terseLabel_en-US" xlink:label="lab_cik0001563922_EnergySalesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Energy sales</link:label>
    <link:label id="lab_cik0001563922_EnergySalesMember_label_en-US" xlink:label="lab_cik0001563922_EnergySalesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Energy Sales [Member]</link:label>
    <link:label id="lab_cik0001563922_EnergySalesMember_documentation_en-US" xlink:label="lab_cik0001563922_EnergySalesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Energy Sales</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_EnergySalesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_EnergySalesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_EnergySalesMember" xlink:to="lab_cik0001563922_EnergySalesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited_019f7115-c6fc-7d2c-8e2a-d385b864472b_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Forfeitures</link:label>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares Issued, Value, Share-Based Payment Arrangement, Forfeited</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited" xlink:to="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeasePayments_019f7115-c671-7ef3-a545-a07e56d15e97_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeasePayments" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Operating cash flows from operating leases</link:label>
    <link:label id="lab_us-gaap_OperatingLeasePayments_label_en-US" xlink:label="lab_us-gaap_OperatingLeasePayments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Payments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeasePayments" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeasePayments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeasePayments" xlink:to="lab_us-gaap_OperatingLeasePayments" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_LongTermDebtCurrentMaturitiesGross_019f7115-c6fc-71a5-ae5b-f236c18cffb5_negatedLabel_en-US" xlink:label="lab_cik0001563922_LongTermDebtCurrentMaturitiesGross" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Current portion of long-term debt, gross</link:label>
    <link:label id="lab_cik0001563922_LongTermDebtCurrentMaturitiesGross_label_en-US" xlink:label="lab_cik0001563922_LongTermDebtCurrentMaturitiesGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Current Maturities, Gross</link:label>
    <link:label id="lab_cik0001563922_LongTermDebtCurrentMaturitiesGross_documentation_en-US" xlink:label="lab_cik0001563922_LongTermDebtCurrentMaturitiesGross" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Current Maturities, Gross</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_LongTermDebtCurrentMaturitiesGross" xlink:href="cik0001563922-20260810.xsd#cik0001563922_LongTermDebtCurrentMaturitiesGross"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_LongTermDebtCurrentMaturitiesGross" xlink:to="lab_cik0001563922_LongTermDebtCurrentMaturitiesGross" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherCommitmentDueInFifthYear_019f7115-c76d-7f81-90b2-9ac91947f706_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCommitmentDueInFifthYear" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2030-2031</link:label>
    <link:label id="lab_us-gaap_OtherCommitmentDueInFifthYear_label_en-US" xlink:label="lab_us-gaap_OtherCommitmentDueInFifthYear" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Commitment, to be Paid, Year Five</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentDueInFifthYear" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentDueInFifthYear"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCommitmentDueInFifthYear" xlink:to="lab_us-gaap_OtherCommitmentDueInFifthYear" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_019f7115-c6fc-7376-8679-344785c1db50_terseLabel_en-US" xlink:label="lab_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impairment of intangible assets (excluding goodwill)</link:label>
    <link:label id="lab_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_label_en-US" xlink:label="lab_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Impairment of Intangible Assets (Excluding Goodwill)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:to="lab_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CurrentForeignTaxExpenseBenefit_019f7115-c5e8-7b48-8946-0c2b98d6b092_terseLabel_en-US" xlink:label="lab_us-gaap_CurrentForeignTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Foreign</link:label>
    <link:label id="lab_us-gaap_CurrentForeignTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_CurrentForeignTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Current Foreign Tax Expense (Benefit)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentForeignTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentForeignTaxExpenseBenefit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CurrentForeignTaxExpenseBenefit" xlink:to="lab_us-gaap_CurrentForeignTaxExpenseBenefit" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_019f7115-c554-7fc9-8a45-08b7c2dd5dda_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Commitments and Contingencies</link:label>
    <link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitments and Contingencies Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_019f7115-c671-73aa-9f17-2c7f60d72d55_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tranche 2 Earnout Shares</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement, Tranche Two [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:to="lab_us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaimPurchases_019f7115-c6fc-70f5-bcdb-748cb6fb749a_terseLabel_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaimPurchases" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contribution to GDEV OYA Lender</link:label>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaimPurchases_label_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaimPurchases" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Bankruptcy Claim, Purchases</link:label>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaimPurchases_documentation_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaimPurchases" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Bankruptcy Claim, Purchases</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaimPurchases" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaimPurchases"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaimPurchases" xlink:to="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaimPurchases" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019f7115-c671-78ee-a504-88062b8d00a2_verboseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Diluted (in shares)</link:label>
    <link:label id="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019f7115-c671-760a-8bb3-41ccd873d898_netLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xml:lang="en-US">Weighted average common shares outstanding used in computing net loss per share&#8212;diluted (in shares)</link:label>
    <link:label id="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_label_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Weighted Average Number of Shares Outstanding, Diluted</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SegmentReportingPolicyPolicyTextBlock_019f7115-c671-7531-b424-31a0f4c5fead_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Segment Information</link:label>
    <link:label id="lab_us-gaap_SegmentReportingPolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segment Reporting, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingPolicyPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:to="lab_us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeTable_019f7115-c671-79fc-97bc-24d094af1195_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative [Table]</link:label>
    <link:label id="lab_us-gaap_DerivativeTable_label_en-US" xlink:label="lab_us-gaap_DerivativeTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeTable" xlink:to="lab_us-gaap_DerivativeTable" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntitySmallBusiness_019f7115-c671-7a88-8c9a-b69c97832c8d_terseLabel_en-US" xlink:label="lab_dei_EntitySmallBusiness" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Small Business</link:label>
    <link:label id="lab_dei_EntitySmallBusiness_label_en-US" xlink:label="lab_dei_EntitySmallBusiness" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Small Business</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitySmallBusiness"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntitySmallBusiness" xlink:to="lab_dei_EntitySmallBusiness" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax Disclosure [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract" xlink:to="lab_us-gaap_IncomeTaxDisclosureAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PaymentsOnFailedSaleLeasebackTransactionInvestingActivity_019f7115-c671-7ec8-91af-78662db96300_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_PaymentsOnFailedSaleLeasebackTransactionInvestingActivity" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Payments on failed sale-leaseback</link:label>
    <link:label id="lab_cik0001563922_PaymentsOnFailedSaleLeasebackTransactionInvestingActivity_label_en-US" xlink:label="lab_cik0001563922_PaymentsOnFailedSaleLeasebackTransactionInvestingActivity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments On Failed Sale Leaseback Transaction, Investing Activity</link:label>
    <link:label id="lab_cik0001563922_PaymentsOnFailedSaleLeasebackTransactionInvestingActivity_documentation_en-US" xlink:label="lab_cik0001563922_PaymentsOnFailedSaleLeasebackTransactionInvestingActivity" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Payments On Failed Sale Leaseback Transaction, Investing Activity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PaymentsOnFailedSaleLeasebackTransactionInvestingActivity" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PaymentsOnFailedSaleLeasebackTransactionInvestingActivity"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PaymentsOnFailedSaleLeasebackTransactionInvestingActivity" xlink:to="lab_cik0001563922_PaymentsOnFailedSaleLeasebackTransactionInvestingActivity" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioDomain_019f7115-c5e8-74af-be0d-aa3478e5cced_terseLabel_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Fee Arrangement, Scenario [Domain]</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioDomain_label_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Fee Arrangement, Scenario [Domain]</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioDomain_documentation_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioDomain" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Fee Arrangement, Scenario</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioDomain" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RelatedPartyTransactionFeeArrangementScenarioDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioDomain" xlink:to="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PreferredStockSharesOutstanding_019f7115-c555-7332-8bcc-b04595e510c7_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Preferred shares, shares outstanding (in shares)</link:label>
    <link:label id="lab_us-gaap_PreferredStockSharesOutstanding_label_en-US" xlink:label="lab_us-gaap_PreferredStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred Stock, Shares Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockSharesOutstanding" xlink:to="lab_us-gaap_PreferredStockSharesOutstanding" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LineOfCreditFacilityCommitmentFeeAmount_019f7115-c5e8-7e31-bbc3-dba5ca9d325e_verboseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityCommitmentFeeAmount" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Commitment / letter of credit fees</link:label>
    <link:label id="lab_us-gaap_LineOfCreditFacilityCommitmentFeeAmount_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityCommitmentFeeAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Commitment Fee Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeeAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityCommitmentFeeAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityCommitmentFeeAmount" xlink:to="lab_us-gaap_LineOfCreditFacilityCommitmentFeeAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_019f7115-c671-7ada-bda8-4c092f31f026_terseLabel_en-US" xlink:label="lab_us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">State</link:label>
    <link:label id="lab_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Current State and Local Tax Expense (Benefit)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:to="lab_us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_EarnoutPeriodAxis_019f7115-c5e8-78a5-84ff-7bb41153ab17_terseLabel_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earnout Period [Axis]</link:label>
    <link:label id="lab_cik0001563922_EarnoutPeriodAxis_label_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Earnout Period [Axis]</link:label>
    <link:label id="lab_cik0001563922_EarnoutPeriodAxis_documentation_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodAxis" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Earnout Period</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_EarnoutPeriodAxis" xlink:href="cik0001563922-20260810.xsd#cik0001563922_EarnoutPeriodAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_EarnoutPeriodAxis" xlink:to="lab_cik0001563922_EarnoutPeriodAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue_019f7115-c555-7d54-ac6a-c3a32829be78_totalLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total lease payments</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue_019f7115-c555-7a36-8e55-b42abaadd349_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total lease payments</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, to be Paid</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DistributionMadeToLimitedLiabilityCompanyLLCMemberLineItems_019f7115-c671-70c8-8151-b70ef54e1c7c_terseLabel_en-US" xlink:label="lab_us-gaap_DistributionMadeToLimitedLiabilityCompanyLLCMemberLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distribution Made to Limited Liability Company (LLC) Member [Line Items]</link:label>
    <link:label id="lab_us-gaap_DistributionMadeToLimitedLiabilityCompanyLLCMemberLineItems_label_en-US" xlink:label="lab_us-gaap_DistributionMadeToLimitedLiabilityCompanyLLCMemberLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distribution Made to Limited Liability Company (LLC) Member [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DistributionMadeToLimitedLiabilityCompanyLLCMemberLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DistributionMadeToLimitedLiabilityCompanyLLCMemberLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DistributionMadeToLimitedLiabilityCompanyLLCMemberLineItems" xlink:to="lab_us-gaap_DistributionMadeToLimitedLiabilityCompanyLLCMemberLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EquityComponentDomain_019f7115-c5e8-7f40-8de9-934cd3c553b8_terseLabel_en-US" xlink:label="lab_us-gaap_EquityComponentDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Equity Component [Domain]</link:label>
    <link:label id="lab_us-gaap_EquityComponentDomain_label_en-US" xlink:label="lab_us-gaap_EquityComponentDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Component [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="lab_us-gaap_EquityComponentDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo_019f7115-c5e8-7d6b-85a1-e0cca29d1a74_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2027-2028</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, to be Paid, Rolling Year Two</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DeferredInvestmentTaxCreditGainIncrementalBorrowingRate_019f7115-c6fc-7002-8eb6-88c3088be10a_terseLabel_en-US" xlink:label="lab_cik0001563922_DeferredInvestmentTaxCreditGainIncrementalBorrowingRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Incremental borrowing rate for deferred investment tax credit gain</link:label>
    <link:label id="lab_cik0001563922_DeferredInvestmentTaxCreditGainIncrementalBorrowingRate_label_en-US" xlink:label="lab_cik0001563922_DeferredInvestmentTaxCreditGainIncrementalBorrowingRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Investment Tax Credit Gain, Incremental Borrowing Rate</link:label>
    <link:label id="lab_cik0001563922_DeferredInvestmentTaxCreditGainIncrementalBorrowingRate_documentation_en-US" xlink:label="lab_cik0001563922_DeferredInvestmentTaxCreditGainIncrementalBorrowingRate" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Deferred Investment Tax Credit Gain, Incremental Borrowing Rate</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DeferredInvestmentTaxCreditGainIncrementalBorrowingRate" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DeferredInvestmentTaxCreditGainIncrementalBorrowingRate"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DeferredInvestmentTaxCreditGainIncrementalBorrowingRate" xlink:to="lab_cik0001563922_DeferredInvestmentTaxCreditGainIncrementalBorrowingRate" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DeferredTaxAssetsOperatingLeaseLiability_019f7115-c555-77e8-9e61-39c2c7b05ac6_terseLabel_en-US" xlink:label="lab_cik0001563922_DeferredTaxAssetsOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating lease liabilities</link:label>
    <link:label id="lab_cik0001563922_DeferredTaxAssetsOperatingLeaseLiability_label_en-US" xlink:label="lab_cik0001563922_DeferredTaxAssetsOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Operating Lease Liability</link:label>
    <link:label id="lab_cik0001563922_DeferredTaxAssetsOperatingLeaseLiability_documentation_en-US" xlink:label="lab_cik0001563922_DeferredTaxAssetsOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Operating Lease Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DeferredTaxAssetsOperatingLeaseLiability" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DeferredTaxAssetsOperatingLeaseLiability"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DeferredTaxAssetsOperatingLeaseLiability" xlink:to="lab_cik0001563922_DeferredTaxAssetsOperatingLeaseLiability" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxDisclosureTextBlock_019f7115-c5e8-7e40-9bd1-810b71b46760_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income Taxes</link:label>
    <link:label id="lab_us-gaap_IncomeTaxDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxDisclosureTextBlock" xlink:to="lab_us-gaap_IncomeTaxDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommonClassAMember_019f7115-c671-7ce6-8550-7783a328b229_terseLabel_en-US" xlink:label="lab_us-gaap_CommonClassAMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class A</link:label>
    <link:label id="lab_us-gaap_CommonClassAMember_label_en-US" xlink:label="lab_us-gaap_CommonClassAMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Class A [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonClassAMember" xlink:to="lab_us-gaap_CommonClassAMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_VariableRateFirstTimeframeMember_019f7115-c5e8-7dec-8b80-81631a558ca5_terseLabel_en-US" xlink:label="lab_cik0001563922_VariableRateFirstTimeframeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Rate, First Timeframe</link:label>
    <link:label id="lab_cik0001563922_VariableRateFirstTimeframeMember_label_en-US" xlink:label="lab_cik0001563922_VariableRateFirstTimeframeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Rate, First Timeframe [Member]</link:label>
    <link:label id="lab_cik0001563922_VariableRateFirstTimeframeMember_documentation_en-US" xlink:label="lab_cik0001563922_VariableRateFirstTimeframeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Variable Rate, First Timeframe</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_VariableRateFirstTimeframeMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_VariableRateFirstTimeframeMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_VariableRateFirstTimeframeMember" xlink:to="lab_cik0001563922_VariableRateFirstTimeframeMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations_019f7115-c5e8-7691-91ba-c248adf25b59_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset retirement obligations</link:label>
    <link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Asset Retirement Obligations</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations" xlink:to="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NumberOfWindRepowerProjects_019f7115-c6fc-7190-920a-f4bbaa88c0f4_terseLabel_en-US" xlink:label="lab_cik0001563922_NumberOfWindRepowerProjects" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of wind repower projects</link:label>
    <link:label id="lab_cik0001563922_NumberOfWindRepowerProjects_label_en-US" xlink:label="lab_cik0001563922_NumberOfWindRepowerProjects" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number Of Wind Repower Projects</link:label>
    <link:label id="lab_cik0001563922_NumberOfWindRepowerProjects_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfWindRepowerProjects" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number Of Wind Repower Projects</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NumberOfWindRepowerProjects" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NumberOfWindRepowerProjects"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NumberOfWindRepowerProjects" xlink:to="lab_cik0001563922_NumberOfWindRepowerProjects" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShortTermLeaseCost_019f7115-c671-7f23-86c5-f7d22fb5f836_terseLabel_en-US" xlink:label="lab_us-gaap_ShortTermLeaseCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Short-term lease cost</link:label>
    <link:label id="lab_us-gaap_ShortTermLeaseCost_label_en-US" xlink:label="lab_us-gaap_ShortTermLeaseCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Short-Term Lease, Cost</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermLeaseCost" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermLeaseCost"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShortTermLeaseCost" xlink:to="lab_us-gaap_ShortTermLeaseCost" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_019f7115-c6fc-7302-a4fc-947179856fd5_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating lease liabilities</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Operating Lease Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:to="lab_us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_WindEnergySystemsMember_019f7115-c671-7212-8af8-9da14762e1ed_terseLabel_en-US" xlink:label="lab_cik0001563922_WindEnergySystemsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Wind energy systems</link:label>
    <link:label id="lab_cik0001563922_WindEnergySystemsMember_label_en-US" xlink:label="lab_cik0001563922_WindEnergySystemsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Wind Energy Systems [Member]</link:label>
    <link:label id="lab_cik0001563922_WindEnergySystemsMember_documentation_en-US" xlink:label="lab_cik0001563922_WindEnergySystemsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Wind Energy Systems</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_WindEnergySystemsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_WindEnergySystemsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_WindEnergySystemsMember" xlink:to="lab_cik0001563922_WindEnergySystemsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ClassPTSharesMember_019f7115-c5e8-7a77-8dbf-012c791685a9_terseLabel_en-US" xlink:label="lab_cik0001563922_ClassPTSharesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class P-T</link:label>
    <link:label id="lab_cik0001563922_ClassPTSharesMember_label_en-US" xlink:label="lab_cik0001563922_ClassPTSharesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class P-T Shares [Member]</link:label>
    <link:label id="lab_cik0001563922_ClassPTSharesMember_documentation_en-US" xlink:label="lab_cik0001563922_ClassPTSharesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Class P-T Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ClassPTSharesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ClassPTSharesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ClassPTSharesMember" xlink:to="lab_cik0001563922_ClassPTSharesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentType_019f7115-c671-7b6e-b4f4-0032f2cd76e8_terseLabel_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Document Type</link:label>
    <link:label id="lab_dei_DocumentType_label_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Type</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentType" xlink:to="lab_dei_DocumentType" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EquityMethodInvestmentsFairValueDisclosure_019f7115-c5e8-7910-9aea-0e20347b0c1e_verboseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Total investments at fair value</link:label>
    <link:label id="lab_us-gaap_EquityMethodInvestmentsFairValueDisclosure_019f7115-c5e8-72ab-9fba-76d8f1f3d84d_terseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investments at fair value</link:label>
    <link:label id="lab_us-gaap_EquityMethodInvestmentsFairValueDisclosure_label_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Method Investments, Fair Value Disclosure</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentsFairValueDisclosure"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:to="lab_us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueInputsLevel3Member_019f7115-c5e8-7392-8964-34de0dbcf513_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel3Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Level 3</link:label>
    <link:label id="lab_us-gaap_FairValueInputsLevel3Member_label_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel3Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Inputs, Level 3 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel3Member" xlink:to="lab_us-gaap_FairValueInputsLevel3Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EarningsPerShareTextBlock_019f7115-c554-7c58-8808-30aa9fd5169a_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earnings Per Share</link:label>
    <link:label id="lab_us-gaap_EarningsPerShareTextBlock_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Earnings Per Share [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareTextBlock" xlink:to="lab_us-gaap_EarningsPerShareTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AdditionalPaidInCapital_019f7115-c6fc-7bfe-af6a-16d9e8ce51ef_terseLabel_en-US" xlink:label="lab_us-gaap_AdditionalPaidInCapital" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Additional paid-in capital</link:label>
    <link:label id="lab_us-gaap_AdditionalPaidInCapital_label_en-US" xlink:label="lab_us-gaap_AdditionalPaidInCapital" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Additional Paid in Capital</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdditionalPaidInCapital" xlink:to="lab_us-gaap_AdditionalPaidInCapital" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_ProductOrServiceAxis_019f7115-c554-76e6-ab85-b8f78c550f20_terseLabel_en-US" xlink:label="lab_srt_ProductOrServiceAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Product and Service [Axis]</link:label>
    <link:label id="lab_srt_ProductOrServiceAxis_label_en-US" xlink:label="lab_srt_ProductOrServiceAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Product and Service [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ProductOrServiceAxis" xlink:to="lab_srt_ProductOrServiceAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetAcquisitionDomain_019f7115-c5e8-7277-842b-ed0e488a74be_terseLabel_en-US" xlink:label="lab_us-gaap_AssetAcquisitionDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset Acquisition [Domain]</link:label>
    <link:label id="lab_us-gaap_AssetAcquisitionDomain_label_en-US" xlink:label="lab_us-gaap_AssetAcquisitionDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Acquisition [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetAcquisitionDomain" xlink:to="lab_us-gaap_AssetAcquisitionDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_VariableLeaseCost_019f7115-c555-7f1b-bf75-248acf038876_terseLabel_en-US" xlink:label="lab_us-gaap_VariableLeaseCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable lease cost</link:label>
    <link:label id="lab_us-gaap_VariableLeaseCost_label_en-US" xlink:label="lab_us-gaap_VariableLeaseCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Lease, Cost</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableLeaseCost" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableLeaseCost"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VariableLeaseCost" xlink:to="lab_us-gaap_VariableLeaseCost" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ProjectTerminationCosts_019f7115-c671-7e6b-a365-41b39a2c7f18_terseLabel_en-US" xlink:label="lab_cik0001563922_ProjectTerminationCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">(Gain) loss on sale of Illinois Winds LLC</link:label>
    <link:label id="lab_cik0001563922_ProjectTerminationCosts_label_en-US" xlink:label="lab_cik0001563922_ProjectTerminationCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Project Termination Costs</link:label>
    <link:label id="lab_cik0001563922_ProjectTerminationCosts_documentation_en-US" xlink:label="lab_cik0001563922_ProjectTerminationCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Project Termination Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ProjectTerminationCosts" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ProjectTerminationCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ProjectTerminationCosts" xlink:to="lab_cik0001563922_ProjectTerminationCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivableAmountReceived_019f7115-c671-73bf-97ef-9c204f40ba4b_terseLabel_en-US" xlink:label="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivableAmountReceived" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Construction loan receivable, amount received</link:label>
    <link:label id="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivableAmountReceived_label_en-US" xlink:label="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivableAmountReceived" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Divestiture Of Interest In Consolidated Subsidiaries, Construction Loan Receivable, Amount Received</link:label>
    <link:label id="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivableAmountReceived_documentation_en-US" xlink:label="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivableAmountReceived" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Divestiture Of Interest In Consolidated Subsidiaries, Construction Loan Receivable, Amount Received</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivableAmountReceived" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivableAmountReceived"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivableAmountReceived" xlink:to="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivableAmountReceived" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f7115-c6fc-7495-8f31-158c03d0f652_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total revenue from contracts with customers</link:label>
    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_label_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue from Contract with Customer, Excluding Assessed Tax</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:to="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CiderSolarConstructionLoanOwnerLLCMember_019f7115-c5e8-7bd0-bdb9-8ec7ee105424_terseLabel_en-US" xlink:label="lab_cik0001563922_CiderSolarConstructionLoanOwnerLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cider Solar Construction Loan Owner LLC</link:label>
    <link:label id="lab_cik0001563922_CiderSolarConstructionLoanOwnerLLCMember_label_en-US" xlink:label="lab_cik0001563922_CiderSolarConstructionLoanOwnerLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cider Solar Construction Loan Owner LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_CiderSolarConstructionLoanOwnerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_CiderSolarConstructionLoanOwnerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cider Solar Construction Loan Owner LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CiderSolarConstructionLoanOwnerLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CiderSolarConstructionLoanOwnerLLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CiderSolarConstructionLoanOwnerLLCMember" xlink:to="lab_cik0001563922_CiderSolarConstructionLoanOwnerLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetAcquisitionConsiderationTransferred_019f7115-c5e8-71c1-8ecc-bd966a568c4e_terseLabel_en-US" xlink:label="lab_us-gaap_AssetAcquisitionConsiderationTransferred" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net purchase price of assets acquired</link:label>
    <link:label id="lab_us-gaap_AssetAcquisitionConsiderationTransferred_label_en-US" xlink:label="lab_us-gaap_AssetAcquisitionConsiderationTransferred" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Acquisition, Consideration Transferred</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferred" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionConsiderationTransferred"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetAcquisitionConsiderationTransferred" xlink:to="lab_us-gaap_AssetAcquisitionConsiderationTransferred" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsCurrent_019f7115-c671-7f8c-8992-8d1e9525a974_totalLabel_en-US" xlink:label="lab_us-gaap_AssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total current assets</link:label>
    <link:label id="lab_us-gaap_AssetsCurrent_label_en-US" xlink:label="lab_us-gaap_AssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Assets, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsCurrent" xlink:to="lab_us-gaap_AssetsCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_RangeAxis_019f7115-c6fc-7652-ae77-b84af85bbf8a_terseLabel_en-US" xlink:label="lab_srt_RangeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statistical Measurement [Axis]</link:label>
    <link:label id="lab_srt_RangeAxis_label_en-US" xlink:label="lab_srt_RangeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statistical Measurement [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RangeAxis" xlink:to="lab_srt_RangeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseVariableLeaseIncome_019f7115-c6fc-79c9-9a8c-7622a3d6e570_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseVariableLeaseIncome" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable lease income</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseVariableLeaseIncome_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseVariableLeaseIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Variable Lease Income</link:label>
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    <link:label id="lab_cik0001563922_AcceleratedDepreciationDueToDamagesIncurred_documentation_en-US" xlink:label="lab_cik0001563922_AcceleratedDepreciationDueToDamagesIncurred" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Accelerated Depreciation Due To Damages Incurred</link:label>
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    <link:label id="lab_us-gaap_DomesticCountryMember_019f7115-c554-78af-85f9-00fb0ff9ad1b_terseLabel_en-US" xlink:label="lab_us-gaap_DomesticCountryMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Domestic Tax Authority</link:label>
    <link:label id="lab_us-gaap_DomesticCountryMember_label_en-US" xlink:label="lab_us-gaap_DomesticCountryMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Domestic Tax Jurisdiction [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DomesticCountryMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DomesticCountryMember" xlink:to="lab_us-gaap_DomesticCountryMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NoncontrollingInterestAbstract_label_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncontrollingInterestAbstract" xlink:to="lab_us-gaap_NoncontrollingInterestAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_InvestmentManagementIMSegmentMember_019f7115-c5e8-744b-8e3d-7473159bc97c_terseLabel_en-US" xlink:label="lab_cik0001563922_InvestmentManagementIMSegmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investment Management</link:label>
    <link:label id="lab_cik0001563922_InvestmentManagementIMSegmentMember_label_en-US" xlink:label="lab_cik0001563922_InvestmentManagementIMSegmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investment Management ("IM") Segment [Member]</link:label>
    <link:label id="lab_cik0001563922_InvestmentManagementIMSegmentMember_documentation_en-US" xlink:label="lab_cik0001563922_InvestmentManagementIMSegmentMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Investment Management ("IM") Segment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_InvestmentManagementIMSegmentMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_InvestmentManagementIMSegmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_InvestmentManagementIMSegmentMember" xlink:to="lab_cik0001563922_InvestmentManagementIMSegmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_019f7115-c6fc-78ef-97ba-e78f3ea2dfc1_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Less: Imputed interest</link:label>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Liability, Undiscounted Excess Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_TaxCreditCarryforwardAxis_019f7115-c555-7b62-845e-d412ea4beb7a_terseLabel_en-US" xlink:label="lab_us-gaap_TaxCreditCarryforwardAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tax Credit Carryforward [Axis]</link:label>
    <link:label id="lab_us-gaap_TaxCreditCarryforwardAxis_label_en-US" xlink:label="lab_us-gaap_TaxCreditCarryforwardAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Tax Credit Carryforward [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TaxCreditCarryforwardAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TaxCreditCarryforwardAxis" xlink:to="lab_us-gaap_TaxCreditCarryforwardAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_019f7115-c554-748b-9e88-9a1f41038a1d_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:to="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NonCashContributionsFromNoncontrollingInterestsNet_019f7115-c5e8-7652-9b47-048234301171_terseLabel_en-US" xlink:label="lab_cik0001563922_NonCashContributionsFromNoncontrollingInterestsNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Non-cash contributions from noncontrolling interests, net</link:label>
    <link:label id="lab_cik0001563922_NonCashContributionsFromNoncontrollingInterestsNet_label_en-US" xlink:label="lab_cik0001563922_NonCashContributionsFromNoncontrollingInterestsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Non-cash Contributions From Noncontrolling Interests, Net</link:label>
    <link:label id="lab_cik0001563922_NonCashContributionsFromNoncontrollingInterestsNet_documentation_en-US" xlink:label="lab_cik0001563922_NonCashContributionsFromNoncontrollingInterestsNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Non-cash Contributions From Noncontrolling Interests, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NonCashContributionsFromNoncontrollingInterestsNet" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NonCashContributionsFromNoncontrollingInterestsNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NonCashContributionsFromNoncontrollingInterestsNet" xlink:to="lab_cik0001563922_NonCashContributionsFromNoncontrollingInterestsNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_019f7115-c5e8-762c-b70f-8c6d3511e03b_totalLabel_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total current assets</link:label>
    <link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_label_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Assets, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:to="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RenewableEnergyProjectsPropertyPlantAndEquipmentMember_019f7115-c5e8-78a4-95eb-9b1cbfdfb4a7_terseLabel_en-US" xlink:label="lab_cik0001563922_RenewableEnergyProjectsPropertyPlantAndEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Renewable Energy Projects, Property, Plant And Equipment</link:label>
    <link:label id="lab_cik0001563922_RenewableEnergyProjectsPropertyPlantAndEquipmentMember_label_en-US" xlink:label="lab_cik0001563922_RenewableEnergyProjectsPropertyPlantAndEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Renewable Energy Projects, Property, Plant And Equipment [Member]</link:label>
    <link:label id="lab_cik0001563922_RenewableEnergyProjectsPropertyPlantAndEquipmentMember_documentation_en-US" xlink:label="lab_cik0001563922_RenewableEnergyProjectsPropertyPlantAndEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Renewable Energy Projects, Property, Plant And Equipment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RenewableEnergyProjectsPropertyPlantAndEquipmentMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RenewableEnergyProjectsPropertyPlantAndEquipmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RenewableEnergyProjectsPropertyPlantAndEquipmentMember" xlink:to="lab_cik0001563922_RenewableEnergyProjectsPropertyPlantAndEquipmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_019f7115-c76d-77a7-be26-c916453a7080_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total debt</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_019f7115-c76d-7ff8-8692-14e7e5ae87ed_netLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xml:lang="en-US">Total debt</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Gross</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount" xlink:to="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid_019f7115-c555-766d-800e-1524eb480613_totalLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total lease payments</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid_019f7115-c555-7579-a16f-9dca31a192f8_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total lease payments</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid" xlink:to="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaid" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVMember_019f7115-c5e8-7cf6-bce5-402e105b472d_terseLabel_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GDEV</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVMember_label_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities Fund I, LP ("GDEV") [Member]</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVMember_documentation_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities Fund I, LP ("GDEV")</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVMember" xlink:to="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_019f7115-c5e8-76e4-8521-18c03bd0545f_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019f7115-c6fc-7364-8625-d5345284a8fd_totalLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total lease payments</link:label>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019f7115-c6fc-780e-968e-76ce177acede_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total lease payments</link:label>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RedeemableNoncontrollingInterestMember_019f7115-c5e8-77a6-8996-b1360b3b5d74_terseLabel_en-US" xlink:label="lab_cik0001563922_RedeemableNoncontrollingInterestMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Redeemable noncontrolling interests</link:label>
    <link:label id="lab_cik0001563922_RedeemableNoncontrollingInterestMember_label_en-US" xlink:label="lab_cik0001563922_RedeemableNoncontrollingInterestMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Redeemable Noncontrolling Interest [Member]</link:label>
    <link:label id="lab_cik0001563922_RedeemableNoncontrollingInterestMember_documentation_en-US" xlink:label="lab_cik0001563922_RedeemableNoncontrollingInterestMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Redeemable Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RedeemableNoncontrollingInterestMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RedeemableNoncontrollingInterestMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RedeemableNoncontrollingInterestMember" xlink:to="lab_cik0001563922_RedeemableNoncontrollingInterestMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_019f7115-c5e8-7419-90f2-f000fc25bae8_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, plant and equipment, net</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_019f7115-c5e8-7f7b-ba50-8faa40e39166_totalLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Property, plant and equipment, net</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_019f7115-c6fc-7f9d-a3c1-6045045c68a3_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Distributions to noncontrolling interests</link:label>
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    <link:label id="lab_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_label_en-US" xlink:label="lab_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>
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    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextRollingTwelveMonths_019f7115-c6fc-75e9-853b-d92ff253ecfa_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextRollingTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026-2027</link:label>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextRollingTwelveMonths_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextRollingTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Maturities, Repayments of Principal in Next Rolling 12 Months</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextRollingTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextRollingTwelveMonths"/>
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    <link:label id="lab_us-gaap_GainLossOnDerivativeInstrumentsNetPretax_019f7115-c671-712e-8a7d-d0fdaa8c65df_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_GainLossOnDerivativeInstrumentsNetPretax" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">(Gain) loss on interest rate swaps, net</link:label>
    <link:label id="lab_us-gaap_GainLossOnDerivativeInstrumentsNetPretax_019f7115-c671-7ed5-ab47-1f7c0e2c527d_negatedLabel_en-US" xlink:label="lab_us-gaap_GainLossOnDerivativeInstrumentsNetPretax" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Loss (gain) on interest rate swaps, net</link:label>
    <link:label id="lab_us-gaap_GainLossOnDerivativeInstrumentsNetPretax_019f7115-c671-7001-9d8d-d7b896748fba_verboseLabel_en-US" xlink:label="lab_us-gaap_GainLossOnDerivativeInstrumentsNetPretax" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Gain on interest rate swaps, net</link:label>
    <link:label id="lab_us-gaap_GainLossOnDerivativeInstrumentsNetPretax_label_en-US" xlink:label="lab_us-gaap_GainLossOnDerivativeInstrumentsNetPretax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Derivative Instruments, Net, Pretax</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDerivativeInstrumentsNetPretax" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnDerivativeInstrumentsNetPretax"/>
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    <link:label id="lab_us-gaap_VariableInterestEntityOwnershipPercentage_019f7115-c671-7633-845f-9462a158a294_terseLabel_en-US" xlink:label="lab_us-gaap_VariableInterestEntityOwnershipPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Ownership percentage</link:label>
    <link:label id="lab_us-gaap_VariableInterestEntityOwnershipPercentage_label_en-US" xlink:label="lab_us-gaap_VariableInterestEntityOwnershipPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityOwnershipPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityOwnershipPercentage"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VariableInterestEntityOwnershipPercentage" xlink:to="lab_us-gaap_VariableInterestEntityOwnershipPercentage" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFive_019f7115-c5e8-7926-954e-dd5550504687_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2030-2031</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFive_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, Rolling Year Five</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFive_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, Rolling Year Five</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFive" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFive"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFive" xlink:to="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFive" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporary_019f7115-c5e8-7693-a4bc-129221ed4d1b_terseLabel_en-US" xlink:label="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporary" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earnout Share participation reclassification to temporary equity</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporary_label_en-US" xlink:label="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporary" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Reclassifications From Permanent Equity To Temporary</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporary_documentation_en-US" xlink:label="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporary" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Temporary Equity, Reclassifications From Permanent Equity To Temporary</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporary" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporary"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporary" xlink:to="lab_cik0001563922_TemporaryEquityReclassificationsFromPermanentEquityToTemporary" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_019f7115-c6fc-77c4-9ad0-a8a31f508d69_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other current and noncurrent liabilities</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Other Operating Liabilities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:to="lab_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense_019f7115-c6fc-7fce-9acd-93f2bea504f0_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Noncontrolling interest</link:label>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense"/>
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    <link:label id="lab_cik0001563922_CommonClassEarnoutMember_019f7115-c671-73b9-bf5b-c532d3707124_terseLabel_en-US" xlink:label="lab_cik0001563922_CommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class EO</link:label>
    <link:label id="lab_cik0001563922_CommonClassEarnoutMember_019f7115-c671-7d73-9a23-d3e6245b2411_verboseLabel_en-US" xlink:label="lab_cik0001563922_CommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Class EO</link:label>
    <link:label id="lab_cik0001563922_CommonClassEarnoutMember_019f7115-c671-7533-968a-4c104340ce23_netLabel_en-US" xlink:label="lab_cik0001563922_CommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xml:lang="en-US">EO Awards</link:label>
    <link:label id="lab_cik0001563922_CommonClassEarnoutMember_label_en-US" xlink:label="lab_cik0001563922_CommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Class Earnout [Member]</link:label>
    <link:label id="lab_cik0001563922_CommonClassEarnoutMember_documentation_en-US" xlink:label="lab_cik0001563922_CommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Common Class Earnout</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CommonClassEarnoutMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CommonClassEarnoutMember"/>
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    <link:label id="lab_us-gaap_RelatedPartyTransactionAmountsOfTransaction_019f7115-c554-788e-977c-6a5b4f05b842_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionAmountsOfTransaction" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Related party transaction, amount of transaction</link:label>
    <link:label id="lab_us-gaap_RelatedPartyTransactionAmountsOfTransaction_label_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionAmountsOfTransaction" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Amounts of Transaction</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionAmountsOfTransaction"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction" xlink:to="lab_us-gaap_RelatedPartyTransactionAmountsOfTransaction" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NonCashTaxBenefitCreditAdjustmentDecreaseToDistributionsToNonControllingInterest_019f7115-c555-7df4-ade4-5d0b9fd3f44d_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_NonCashTaxBenefitCreditAdjustmentDecreaseToDistributionsToNonControllingInterest" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">ITC sales proceeds distributed to noncontrolling interests</link:label>
    <link:label id="lab_cik0001563922_NonCashTaxBenefitCreditAdjustmentDecreaseToDistributionsToNonControllingInterest_label_en-US" xlink:label="lab_cik0001563922_NonCashTaxBenefitCreditAdjustmentDecreaseToDistributionsToNonControllingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Non Cash Tax Benefit Credit Adjustment, Decrease to Distributions to Non-controlling Interest</link:label>
    <link:label id="lab_cik0001563922_NonCashTaxBenefitCreditAdjustmentDecreaseToDistributionsToNonControllingInterest_documentation_en-US" xlink:label="lab_cik0001563922_NonCashTaxBenefitCreditAdjustmentDecreaseToDistributionsToNonControllingInterest" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Non Cash Tax Benefit Credit Adjustment, Decrease to Distributions to Non-controlling Interest</link:label>
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    <link:label id="lab_cik0001563922_RedeemableCommonSharesMember_019f7115-c6fc-788a-bc82-66cf812e6099_terseLabel_en-US" xlink:label="lab_cik0001563922_RedeemableCommonSharesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Redeemable common shares</link:label>
    <link:label id="lab_cik0001563922_RedeemableCommonSharesMember_label_en-US" xlink:label="lab_cik0001563922_RedeemableCommonSharesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Redeemable Common Shares [Member]</link:label>
    <link:label id="lab_cik0001563922_RedeemableCommonSharesMember_documentation_en-US" xlink:label="lab_cik0001563922_RedeemableCommonSharesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Redeemable Common Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RedeemableCommonSharesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RedeemableCommonSharesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RedeemableCommonSharesMember" xlink:to="lab_cik0001563922_RedeemableCommonSharesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseAndFinancingCosts_019f7115-c671-77a8-afd9-01f270018815_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseAndFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest on sale-leasebacks</link:label>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseAndFinancingCosts_label_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseAndFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale And Leaseback Transaction, Interest Expense And Financing Costs</link:label>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseAndFinancingCosts_documentation_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseAndFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale And Leaseback Transaction, Interest Expense And Financing Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleAndLeasebackTransactionInterestExpenseAndFinancingCosts" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleAndLeasebackTransactionInterestExpenseAndFinancingCosts"/>
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    <link:label id="lab_us-gaap_EquityMethodInvestmentsTextBlock_019f7115-c6fc-7c29-b350-cba8ca00db15_terseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Equity Method Investments</link:label>
    <link:label id="lab_us-gaap_EquityMethodInvestmentsTextBlock_label_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Method Investments [Table Text Block]</link:label>
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    <link:label id="lab_cik0001563922_TurquoiseManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_TurquoiseManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Turquoise Manager LLC</link:label>
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    <link:label id="lab_us-gaap_InvestmentsMember_019f7115-c554-71ac-bf67-6dcfc7ded905_terseLabel_en-US" xlink:label="lab_us-gaap_InvestmentsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investments at fair value</link:label>
    <link:label id="lab_us-gaap_InvestmentsMember_label_en-US" xlink:label="lab_us-gaap_InvestmentsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investments [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InvestmentsMember" xlink:to="lab_us-gaap_InvestmentsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RestructuringCharges_019f7115-c6fc-751a-8e90-e95f037128ef_terseLabel_en-US" xlink:label="lab_us-gaap_RestructuringCharges" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Restructuring charges</link:label>
    <link:label id="lab_us-gaap_RestructuringCharges_label_en-US" xlink:label="lab_us-gaap_RestructuringCharges" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restructuring Charges</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestructuringCharges"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestructuringCharges" xlink:to="lab_us-gaap_RestructuringCharges" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsOfCapitalDistribution_019f7115-c5e8-784b-b3dc-921015c2dac5_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsOfCapitalDistribution" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Shareholder distributions</link:label>
    <link:label id="lab_us-gaap_PaymentsOfCapitalDistribution_label_en-US" xlink:label="lab_us-gaap_PaymentsOfCapitalDistribution" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments of Capital Distribution</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfCapitalDistribution" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfCapitalDistribution"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsOfCapitalDistribution" xlink:to="lab_us-gaap_PaymentsOfCapitalDistribution" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncreaseDecreaseInAccountsReceivable_019f7115-c5e8-75f5-bc97-bfb204bebe6d_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Accounts receivable</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInAccountsReceivable_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Accounts Receivable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="lab_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConstructionLoansMember_019f7115-c5e8-7096-8e79-7df6905200c1_terseLabel_en-US" xlink:label="lab_us-gaap_ConstructionLoansMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Construction Loan</link:label>
    <link:label id="lab_us-gaap_ConstructionLoansMember_label_en-US" xlink:label="lab_us-gaap_ConstructionLoansMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Construction Loans [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionLoansMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionLoansMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConstructionLoansMember" xlink:to="lab_us-gaap_ConstructionLoansMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ReceivablesAbstract_label_en-US" xlink:label="lab_us-gaap_ReceivablesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Receivables [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReceivablesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ReceivablesAbstract" xlink:to="lab_us-gaap_ReceivablesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeLineItems_019f7115-c671-7ffa-ad32-d7a73c22991c_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative [Line Items]</link:label>
    <link:label id="lab_us-gaap_DerivativeLineItems_label_en-US" xlink:label="lab_us-gaap_DerivativeLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeLineItems" xlink:to="lab_us-gaap_DerivativeLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIILPAndGreenbackerDevelopmentOpportunitiesFundIILPBGDEVIIMember_019f7115-c671-7d20-8da4-3c67e5cc6eb2_terseLabel_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIILPAndGreenbackerDevelopmentOpportunitiesFundIILPBGDEVIIMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GDEV II</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIILPAndGreenbackerDevelopmentOpportunitiesFundIILPBGDEVIIMember_label_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIILPAndGreenbackerDevelopmentOpportunitiesFundIILPBGDEVIIMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities Fund II, LP and Greenbacker Development Opportunities Fund II, LP (B) ("GDEV II") [Member]</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIILPAndGreenbackerDevelopmentOpportunitiesFundIILPBGDEVIIMember_documentation_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIILPAndGreenbackerDevelopmentOpportunitiesFundIILPBGDEVIIMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities Fund II, LP and Greenbacker Development Opportunities Fund II, LP (B)</link:label>
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    <link:label id="lab_srt_ConsolidatedEntitiesDomain_019f7115-c6fc-7567-82e3-91bcd60e8acc_terseLabel_en-US" xlink:label="lab_srt_ConsolidatedEntitiesDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Consolidated Entities [Domain]</link:label>
    <link:label id="lab_srt_ConsolidatedEntitiesDomain_label_en-US" xlink:label="lab_srt_ConsolidatedEntitiesDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidated Entities [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ConsolidatedEntitiesDomain" xlink:to="lab_srt_ConsolidatedEntitiesDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LossOnContractTermination_019f7115-c5e8-7137-b6e9-c7cf05cf64fe_terseLabel_en-US" xlink:label="lab_us-gaap_LossOnContractTermination" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Loss on contract termination</link:label>
    <link:label id="lab_us-gaap_LossOnContractTermination_label_en-US" xlink:label="lab_us-gaap_LossOnContractTermination" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loss on Contract Termination</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossOnContractTermination" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossOnContractTermination"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossOnContractTermination" xlink:to="lab_us-gaap_LossOnContractTermination" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_019f7115-c6fc-7233-9e49-3cba26366130_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tax (benefit) at statutory U.S. federal income tax rate</link:label>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_label_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate"/>
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    <link:label id="lab_cik0001563922_WindRepowerProjectsAcceleratedDepreciation_019f7115-c671-75c7-a67a-16148849e0db_terseLabel_en-US" xlink:label="lab_cik0001563922_WindRepowerProjectsAcceleratedDepreciation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accelerated depreciation</link:label>
    <link:label id="lab_cik0001563922_WindRepowerProjectsAcceleratedDepreciation_label_en-US" xlink:label="lab_cik0001563922_WindRepowerProjectsAcceleratedDepreciation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Wind Repower Projects, Accelerated Depreciation</link:label>
    <link:label id="lab_cik0001563922_WindRepowerProjectsAcceleratedDepreciation_documentation_en-US" xlink:label="lab_cik0001563922_WindRepowerProjectsAcceleratedDepreciation" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Wind Repower Projects, Accelerated Depreciation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_WindRepowerProjectsAcceleratedDepreciation" xlink:href="cik0001563922-20260810.xsd#cik0001563922_WindRepowerProjectsAcceleratedDepreciation"/>
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    <link:label id="lab_us-gaap_FinancialInstrumentAxis_019f7115-c554-7d50-a356-7be7b0bf93b1_terseLabel_en-US" xlink:label="lab_us-gaap_FinancialInstrumentAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Financial Instrument [Axis]</link:label>
    <link:label id="lab_us-gaap_FinancialInstrumentAxis_label_en-US" xlink:label="lab_us-gaap_FinancialInstrumentAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Financial Instrument [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
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    <link:label id="lab_us-gaap_StatementOfFinancialPositionAbstract_019f7115-c5e8-76c6-bb50-0e8c70d5a6c6_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement of Financial Position [Abstract]</link:label>
    <link:label id="lab_us-gaap_StatementOfFinancialPositionAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Financial Position [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
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    <link:label id="lab_cik0001563922_GainLossForAssignmentRelatedToBenefitOfCreditors_documentation_en-US" xlink:label="lab_cik0001563922_GainLossForAssignmentRelatedToBenefitOfCreditors" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Gain (Loss) For Assignment Related To Benefit Of Creditors</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GainLossForAssignmentRelatedToBenefitOfCreditors" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GainLossForAssignmentRelatedToBenefitOfCreditors"/>
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    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_019f7115-c671-765f-8d70-001902f69c2c_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">State income taxes, net of federal benefit</link:label>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
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    <link:label id="lab_us-gaap_FinanceLeaseLiabilityCurrent_019f7115-c5e8-76e7-b526-1a0a2164d2aa_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityCurrent" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Other current liabilities</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityCurrent_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityCurrent" xlink:to="lab_us-gaap_FinanceLeaseLiabilityCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019f7115-c671-764b-9494-fe3c43b8bd0d_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from borrowings</link:label>
    <link:label id="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebt_label_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from Issuance of Long-Term Debt</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:to="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f7115-c5e8-795d-a985-06ebbcb1dd46_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets, Major Class Name [Domain]</link:label>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets, Major Class Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NumberOfSolarProjects_019f7115-c6fc-7cbd-90b1-c15a03df9bbb_terseLabel_en-US" xlink:label="lab_cik0001563922_NumberOfSolarProjects" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of solar projects</link:label>
    <link:label id="lab_cik0001563922_NumberOfSolarProjects_label_en-US" xlink:label="lab_cik0001563922_NumberOfSolarProjects" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number Of Solar Projects</link:label>
    <link:label id="lab_cik0001563922_NumberOfSolarProjects_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfSolarProjects" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number Of Solar Projects</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NumberOfSolarProjects" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NumberOfSolarProjects"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NumberOfSolarProjects" xlink:to="lab_cik0001563922_NumberOfSolarProjects" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearTwo_019f7115-c76d-7bac-b2ec-268c39a01bc1_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2027-2028</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearTwo_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, Rolling Year Two</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearTwo_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, Rolling Year Two</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearTwo" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearTwo"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearTwo" xlink:to="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearTwo" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_019f7115-c671-78f2-b952-3fcdce26737a_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Shares available for future grants (in shares)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProfessionalFees_019f7115-c6fc-76ac-b3a4-1d2d2044fb70_terseLabel_en-US" xlink:label="lab_us-gaap_ProfessionalFees" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Professional fees</link:label>
    <link:label id="lab_us-gaap_ProfessionalFees_label_en-US" xlink:label="lab_us-gaap_ProfessionalFees" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Professional Fees</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfessionalFees"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProfessionalFees" xlink:to="lab_us-gaap_ProfessionalFees" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019f7115-c6fc-766b-8425-9c74332a0073_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Weighted Average Fair Value</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeLiabilities_019f7115-c6fc-757a-83cb-cdcab20e6c22_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DerivativeLiabilities" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Derivative liabilities</link:label>
    <link:label id="lab_us-gaap_DerivativeLiabilities_019f7115-c6fc-759a-8aa0-d9f15e4c2dc7_negatedNetLabel_en-US" xlink:label="lab_us-gaap_DerivativeLiabilities" xlink:role="http://www.xbrl.org/2009/role/negatedNetLabel" xlink:type="resource" xml:lang="en-US">Fair Value - (Liabilities)</link:label>
    <link:label id="lab_us-gaap_DerivativeLiabilities_label_en-US" xlink:label="lab_us-gaap_DerivativeLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeLiabilities" xlink:to="lab_us-gaap_DerivativeLiabilities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive_019f7115-c5e8-7b15-8525-377fe79fb365_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2030-2031</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, to be Paid, Rolling Year Five</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MinorityInterestDisclosureTextBlock_019f7115-c671-7768-ac27-d27dafce7b29_terseLabel_en-US" xlink:label="lab_us-gaap_MinorityInterestDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Noncontrolling Interests and Redeemable Noncontrolling Interests</link:label>
    <link:label id="lab_us-gaap_MinorityInterestDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_MinorityInterestDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MinorityInterestDisclosureTextBlock" xlink:to="lab_us-gaap_MinorityInterestDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_OneCustomerMember_019f7115-c671-7635-9320-a9a40125dc5e_terseLabel_en-US" xlink:label="lab_cik0001563922_OneCustomerMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">One Customer</link:label>
    <link:label id="lab_cik0001563922_OneCustomerMember_label_en-US" xlink:label="lab_cik0001563922_OneCustomerMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">One Customer [Member]</link:label>
    <link:label id="lab_cik0001563922_OneCustomerMember_documentation_en-US" xlink:label="lab_cik0001563922_OneCustomerMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">One Customer</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OneCustomerMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OneCustomerMember"/>
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    <link:label id="lab_cik0001563922_BaseManagementFeePayableMonthlyRate_019f7115-c671-764f-b18d-dfc04e7464ce_terseLabel_en-US" xlink:label="lab_cik0001563922_BaseManagementFeePayableMonthlyRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Base management fee payable, monthly rate (percent)</link:label>
    <link:label id="lab_cik0001563922_BaseManagementFeePayableMonthlyRate_label_en-US" xlink:label="lab_cik0001563922_BaseManagementFeePayableMonthlyRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Base Management Fee Payable, Monthly Rate</link:label>
    <link:label id="lab_cik0001563922_BaseManagementFeePayableMonthlyRate_documentation_en-US" xlink:label="lab_cik0001563922_BaseManagementFeePayableMonthlyRate" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Base management fees payable to GCM, monthly rate, calculated at a percentage of gross assets (including amounts borrowed).</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_BaseManagementFeePayableMonthlyRate" xlink:to="lab_cik0001563922_BaseManagementFeePayableMonthlyRate" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_019f7115-c5e8-7e81-9ff9-fea66b088516_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Return of capital on investments</link:label>
    <link:label id="lab_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_label_en-US" xlink:label="lab_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from Sale and Maturity of Marketable Securities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities"/>
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    <link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019f7115-c671-753d-9eef-b384877008e0_terseLabel_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Anti-dilutive shares excluded from calculation of diluted earnings per share (in shares)</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
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    <link:label id="lab_cik0001563922_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuanceSyndicationCosts_019f7115-c5e8-7363-b23c-0dd7af84a491_terseLabel_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuanceSyndicationCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Less: Syndication costs</link:label>
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    <link:label id="lab_us-gaap_FairValueByBalanceSheetGroupingTable_019f7115-c6fc-7577-b363-4f43b09fa988_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByBalanceSheetGroupingTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value, by Balance Sheet Grouping [Table]</link:label>
    <link:label id="lab_us-gaap_FairValueByBalanceSheetGroupingTable_label_en-US" xlink:label="lab_us-gaap_FairValueByBalanceSheetGroupingTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, by Balance Sheet Grouping [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable" xlink:to="lab_us-gaap_FairValueByBalanceSheetGroupingTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_019f7115-c5e8-797a-9ba3-d3105efc0777_verboseLabel_en-US" xlink:label="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Accounts payable and accrued expenses</link:label>
    <link:label id="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_label_en-US" xlink:label="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts Payable and Accrued Liabilities, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:to="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherCommitmentsTable_019f7115-c554-7672-9b73-dec35918e7b4_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCommitmentsTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other Commitments [Table]</link:label>
    <link:label id="lab_us-gaap_OtherCommitmentsTable_label_en-US" xlink:label="lab_us-gaap_OtherCommitmentsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Commitments [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCommitmentsTable" xlink:to="lab_us-gaap_OtherCommitmentsTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LesseeOperatingLeasesTextBlock_019f7115-c6fc-7101-a72c-f808f7cbdc3a_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeasesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Leases</link:label>
    <link:label id="lab_us-gaap_LesseeOperatingLeasesTextBlock_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeasesTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Leases [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeasesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeasesTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeasesTextBlock" xlink:to="lab_us-gaap_LesseeOperatingLeasesTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities_019f7115-c6fc-753f-a729-c6e8889cb8bc_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash provided by financing activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash Provided by (Used in) Financing Activity, Including Discontinued Operation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
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    <link:label id="lab_us-gaap_ProvisionForLoanLossesExpensed_019f7115-c6fc-7c58-b84a-5a29fdc7ab70_terseLabel_en-US" xlink:label="lab_us-gaap_ProvisionForLoanLossesExpensed" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Notes receivable loss reserves</link:label>
    <link:label id="lab_us-gaap_ProvisionForLoanLossesExpensed_label_en-US" xlink:label="lab_us-gaap_ProvisionForLoanLossesExpensed" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Financing Receivable, Credit Loss, Expense (Reversal)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProvisionForLoanLossesExpensed" xlink:to="lab_us-gaap_ProvisionForLoanLossesExpensed" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PonderosaManagerLLCMember_019f7115-c555-7f07-9634-2c923bb429b3_terseLabel_en-US" xlink:label="lab_cik0001563922_PonderosaManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Ponderosa Manager LLC</link:label>
    <link:label id="lab_cik0001563922_PonderosaManagerLLCMember_label_en-US" xlink:label="lab_cik0001563922_PonderosaManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Ponderosa Manager LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_PonderosaManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_PonderosaManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Ponderosa Manager LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PonderosaManagerLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PonderosaManagerLLCMember"/>
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    <link:label id="lab_us-gaap_ContractWithCustomerReceivableAfterAllowanceForCreditLossCurrent_019f7115-c5e8-7c8d-81f8-ffb62dcb861b_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerReceivableAfterAllowanceForCreditLossCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Receivable related to contracts with customers</link:label>
    <link:label id="lab_us-gaap_ContractWithCustomerReceivableAfterAllowanceForCreditLossCurrent_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerReceivableAfterAllowanceForCreditLossCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract with Customer, Receivable, after Allowance for Credit Loss, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerReceivableAfterAllowanceForCreditLossCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerReceivableAfterAllowanceForCreditLossCurrent"/>
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    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionInterestExpenseAndDeferredInvestmentTaxCreditGain_019f7115-c555-7670-b1a5-52331b6198e4_terseLabel_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionInterestExpenseAndDeferredInvestmentTaxCreditGain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest expense on failed sale-leaseback financing and deferred ITC gain</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionInterestExpenseAndDeferredInvestmentTaxCreditGain_label_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionInterestExpenseAndDeferredInvestmentTaxCreditGain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Interest Expense And Deferred Investment Tax Credit Gain</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionInterestExpenseAndDeferredInvestmentTaxCreditGain_documentation_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionInterestExpenseAndDeferredInvestmentTaxCreditGain" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Interest Expense And Deferred Investment Tax Credit Gain</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FailedSaleLeasebackTransactionInterestExpenseAndDeferredInvestmentTaxCreditGain" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FailedSaleLeasebackTransactionInterestExpenseAndDeferredInvestmentTaxCreditGain"/>
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    <link:label id="lab_cik0001563922_ServiceBasedRestrictedStockUnitsMember_019f7115-c6fc-7c1e-8edb-aea28d85bf0c_terseLabel_en-US" xlink:label="lab_cik0001563922_ServiceBasedRestrictedStockUnitsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Service Based Restricted Stock Units</link:label>
    <link:label id="lab_cik0001563922_ServiceBasedRestrictedStockUnitsMember_label_en-US" xlink:label="lab_cik0001563922_ServiceBasedRestrictedStockUnitsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Service Based Restricted Stock Units [Member]</link:label>
    <link:label id="lab_cik0001563922_ServiceBasedRestrictedStockUnitsMember_documentation_en-US" xlink:label="lab_cik0001563922_ServiceBasedRestrictedStockUnitsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Service Based Restricted Stock Units</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ServiceBasedRestrictedStockUnitsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ServiceBasedRestrictedStockUnitsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ServiceBasedRestrictedStockUnitsMember" xlink:to="lab_cik0001563922_ServiceBasedRestrictedStockUnitsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f7115-c671-731a-9832-95b08b56ddbf_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-Lived Tangible Asset [Domain]</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Lived Tangible Asset [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisposalGroupClassificationDomain_019f7115-c671-730b-9442-d924bf75cdfb_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupClassificationDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Disposal Group Classification [Domain]</link:label>
    <link:label id="lab_us-gaap_DisposalGroupClassificationDomain_label_en-US" xlink:label="lab_us-gaap_DisposalGroupClassificationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group Classification [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisposalGroupClassificationDomain"/>
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    <link:label id="lab_cik0001563922_VariableRateSecondTimeframeMember_019f7115-c5e8-7613-8e51-0cf4fec06ac3_terseLabel_en-US" xlink:label="lab_cik0001563922_VariableRateSecondTimeframeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Rate, Second Timeframe</link:label>
    <link:label id="lab_cik0001563922_VariableRateSecondTimeframeMember_label_en-US" xlink:label="lab_cik0001563922_VariableRateSecondTimeframeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Rate, Second Timeframe [Member]</link:label>
    <link:label id="lab_cik0001563922_VariableRateSecondTimeframeMember_documentation_en-US" xlink:label="lab_cik0001563922_VariableRateSecondTimeframeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Variable Rate, Second Timeframe</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_VariableRateSecondTimeframeMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_VariableRateSecondTimeframeMember"/>
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    <link:label id="lab_us-gaap_LossContingencyReceivable_019f7115-c554-7a71-9308-00750f1277cd_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingencyReceivable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Insurance recovery receivable</link:label>
    <link:label id="lab_us-gaap_LossContingencyReceivable_label_en-US" xlink:label="lab_us-gaap_LossContingencyReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loss Contingency, Receivable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyReceivable"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DiscontinuedOperationsDisposedOfByMeansOtherThanSaleMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DiscontinuedOperationsDisposedOfByMeansOtherThanSaleMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DiscontinuedOperationsDisposedOfByMeansOtherThanSaleMember" xlink:to="lab_us-gaap_DiscontinuedOperationsDisposedOfByMeansOtherThanSaleMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_KaneWarehouseLoanMember_019f7115-c671-7a92-bb12-1dd9d5e00678_terseLabel_en-US" xlink:label="lab_cik0001563922_KaneWarehouseLoanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Kane Warehouse</link:label>
    <link:label id="lab_cik0001563922_KaneWarehouseLoanMember_label_en-US" xlink:label="lab_cik0001563922_KaneWarehouseLoanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Kane Warehouse Loan [Member]</link:label>
    <link:label id="lab_cik0001563922_KaneWarehouseLoanMember_documentation_en-US" xlink:label="lab_cik0001563922_KaneWarehouseLoanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Kane Warehouse Loan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_KaneWarehouseLoanMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_KaneWarehouseLoanMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_KaneWarehouseLoanMember" xlink:to="lab_cik0001563922_KaneWarehouseLoanMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019f7115-c5e8-74b1-a418-96a395b3fdc7_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Risk-free interest rate</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits_019f7115-c5e8-7834-b6e1-6bceb291005c_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Federal tax credits</link:label>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Tax Credit, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits" xlink:to="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetAcquisitionAxis_019f7115-c671-76a6-8121-e6d93fdedf1e_terseLabel_en-US" xlink:label="lab_us-gaap_AssetAcquisitionAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset Acquisition [Axis]</link:label>
    <link:label id="lab_us-gaap_AssetAcquisitionAxis_label_en-US" xlink:label="lab_us-gaap_AssetAcquisitionAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Acquisition [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetAcquisitionAxis" xlink:to="lab_us-gaap_AssetAcquisitionAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RenewableEnergyCreditRECMember_019f7115-c6fc-7a69-a17d-bb48fab6a94c_terseLabel_en-US" xlink:label="lab_cik0001563922_RenewableEnergyCreditRECMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">REC contracts</link:label>
    <link:label id="lab_cik0001563922_RenewableEnergyCreditRECMember_label_en-US" xlink:label="lab_cik0001563922_RenewableEnergyCreditRECMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Renewable Energy Credit ("REC") [Member]</link:label>
    <link:label id="lab_cik0001563922_RenewableEnergyCreditRECMember_documentation_en-US" xlink:label="lab_cik0001563922_RenewableEnergyCreditRECMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Renewable Energy Credit ("REC")</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RenewableEnergyCreditRECMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RenewableEnergyCreditRECMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RenewableEnergyCreditRECMember" xlink:to="lab_cik0001563922_RenewableEnergyCreditRECMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommonStockSharesIssued_019f7115-c76d-7cce-b2e2-56314bb2f643_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common shares, shares issued (in shares)</link:label>
    <link:label id="lab_us-gaap_CommonStockSharesIssued_label_en-US" xlink:label="lab_us-gaap_CommonStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock, Shares, Issued</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesIssued" xlink:to="lab_us-gaap_CommonStockSharesIssued" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration_019f7115-c671-7e04-864d-f6d57ad9f133_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative Asset, Statement of Financial Position [Extensible Enumeration]</link:label>
    <link:label id="lab_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration_label_en-US" xlink:label="lab_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Asset, Statement of Financial Position [Extensible Enumeration]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration" xlink:to="lab_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_019f7115-c5e8-752c-ac4a-01cade67968a_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Weighted-average remaining lease term - operating leases (in years)</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Weighted Average Remaining Lease Term</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RedeemableNoncontrollingInterestTableTextBlock_019f7115-c5e8-789d-900a-2203e9b96f16_terseLabel_en-US" xlink:label="lab_us-gaap_RedeemableNoncontrollingInterestTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Redeemable Noncontrolling Interest Attributable to Tax Equity Investors</link:label>
    <link:label id="lab_us-gaap_RedeemableNoncontrollingInterestTableTextBlock_label_en-US" xlink:label="lab_us-gaap_RedeemableNoncontrollingInterestTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Redeemable Noncontrolling Interest [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableNoncontrollingInterestTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RedeemableNoncontrollingInterestTableTextBlock" xlink:to="lab_us-gaap_RedeemableNoncontrollingInterestTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivable_019f7115-c555-7e9c-97f8-269fb898f123_terseLabel_en-US" xlink:label="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Construction loan receivable</link:label>
    <link:label id="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivable_label_en-US" xlink:label="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Divestiture Of Interest In Consolidated Subsidiaries, Construction Loan Receivable</link:label>
    <link:label id="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivable_documentation_en-US" xlink:label="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Divestiture Of Interest In Consolidated Subsidiaries, Construction Loan Receivable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivable" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivable" xlink:to="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesConstructionLoanReceivable" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_InvestmentMeasurementInput_019f7115-c6fc-7e91-ba3d-828abb10c665_terseLabel_en-US" xlink:label="lab_cik0001563922_InvestmentMeasurementInput" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investment, measurement input</link:label>
    <link:label id="lab_cik0001563922_InvestmentMeasurementInput_label_en-US" xlink:label="lab_cik0001563922_InvestmentMeasurementInput" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investment, Measurement Input</link:label>
    <link:label id="lab_cik0001563922_InvestmentMeasurementInput_documentation_en-US" xlink:label="lab_cik0001563922_InvestmentMeasurementInput" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Investment, Measurement Input</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_InvestmentMeasurementInput" xlink:href="cik0001563922-20260810.xsd#cik0001563922_InvestmentMeasurementInput"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_InvestmentMeasurementInput" xlink:to="lab_cik0001563922_InvestmentMeasurementInput" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DividendsPayableCurrent_019f7115-c554-7966-a6ef-dba06f6f1437_terseLabel_en-US" xlink:label="lab_us-gaap_DividendsPayableCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Shareholder distributions payable</link:label>
    <link:label id="lab_us-gaap_DividendsPayableCurrent_label_en-US" xlink:label="lab_us-gaap_DividendsPayableCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dividends Payable, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsPayableCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DividendsPayableCurrent" xlink:to="lab_us-gaap_DividendsPayableCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeAssetsCurrent_019f7115-c671-7205-b512-c50946ef1477_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative assets, current</link:label>
    <link:label id="lab_us-gaap_DerivativeAssetsCurrent_label_en-US" xlink:label="lab_us-gaap_DerivativeAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Asset, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetsCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeAssetsCurrent" xlink:to="lab_us-gaap_DerivativeAssetsCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseLeaseIncome_019f7115-c5e8-7ef7-9c94-ba7cc8d3cde8_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLeaseIncome" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Less: Lease revenue</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLeaseIncome_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLeaseIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Lease Income</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLeaseIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLeaseIncome"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLeaseIncome" xlink:to="lab_us-gaap_OperatingLeaseLeaseIncome" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019f7115-c6fc-7353-9c23-f1d49a35fd0a_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Change in contingent consideration</link:label>
    <link:label id="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_label_en-US" xlink:label="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:to="lab_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CorporateNonSegmentMember_019f7115-c555-7c28-b21e-76a53f5f6ffb_terseLabel_en-US" xlink:label="lab_us-gaap_CorporateNonSegmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">All Other</link:label>
    <link:label id="lab_us-gaap_CorporateNonSegmentMember_label_en-US" xlink:label="lab_us-gaap_CorporateNonSegmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CorporateNonSegmentMember" xlink:to="lab_us-gaap_CorporateNonSegmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesClassOfPIMember_019f7115-c6fc-7b68-a4ac-a9eeba94a298_terseLabel_en-US" xlink:label="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesClassOfPIMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Additional Paid-In-Capital, Redeemable Common Shares, Class of P-I</link:label>
    <link:label id="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesClassOfPIMember_label_en-US" xlink:label="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesClassOfPIMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Additional Paid-In-Capital, Redeemable Common Shares, Class Of P-I [Member]</link:label>
    <link:label id="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesClassOfPIMember_documentation_en-US" xlink:label="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesClassOfPIMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Additional Paid-In-Capital, Redeemable Common Shares, Class Of P-I</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesClassOfPIMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesClassOfPIMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesClassOfPIMember" xlink:to="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesClassOfPIMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesNoncurrent_019f7115-c5e8-753b-bcbe-7dd61a5e7068_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total noncurrent liabilities</link:label>
    <link:label id="lab_us-gaap_LiabilitiesNoncurrent_label_en-US" xlink:label="lab_us-gaap_LiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Liabilities, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesNoncurrent" xlink:to="lab_us-gaap_LiabilitiesNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NumberOfSoldSolarAsset_019f7115-c554-7b63-8647-837e212ce088_terseLabel_en-US" xlink:label="lab_cik0001563922_NumberOfSoldSolarAsset" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of sold solar asset</link:label>
    <link:label id="lab_cik0001563922_NumberOfSoldSolarAsset_label_en-US" xlink:label="lab_cik0001563922_NumberOfSoldSolarAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number Of Sold Solar Asset</link:label>
    <link:label id="lab_cik0001563922_NumberOfSoldSolarAsset_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfSoldSolarAsset" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number Of Sold Solar Asset</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NumberOfSoldSolarAsset" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NumberOfSoldSolarAsset"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NumberOfSoldSolarAsset" xlink:to="lab_cik0001563922_NumberOfSoldSolarAsset" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinancingReceivablesTextBlock_019f7115-c671-710d-b1fa-d82dc966223a_terseLabel_en-US" xlink:label="lab_us-gaap_FinancingReceivablesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Notes Receivable</link:label>
    <link:label id="lab_us-gaap_FinancingReceivablesTextBlock_label_en-US" xlink:label="lab_us-gaap_FinancingReceivablesTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Financing Receivables [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablesTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinancingReceivablesTextBlock" xlink:to="lab_us-gaap_FinancingReceivablesTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid_019f7115-c671-7cbc-ad2b-03a6ec5ef475_terseLabel_en-US" xlink:label="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Capital expenditures incurred but not paid</link:label>
    <link:label id="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid_label_en-US" xlink:label="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Capital Expenditures Incurred but Not yet Paid</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:to="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CommonStockSharesOtherCapitalActivity_019f7115-c671-7cd0-8091-a904b15dbdf4_terseLabel_en-US" xlink:label="lab_cik0001563922_CommonStockSharesOtherCapitalActivity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other capital activity (in shares)</link:label>
    <link:label id="lab_cik0001563922_CommonStockSharesOtherCapitalActivity_label_en-US" xlink:label="lab_cik0001563922_CommonStockSharesOtherCapitalActivity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock, Shares, Other Capital Activity</link:label>
    <link:label id="lab_cik0001563922_CommonStockSharesOtherCapitalActivity_documentation_en-US" xlink:label="lab_cik0001563922_CommonStockSharesOtherCapitalActivity" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Common Stock, Shares, Other Capital Activity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CommonStockSharesOtherCapitalActivity" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CommonStockSharesOtherCapitalActivity"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CommonStockSharesOtherCapitalActivity" xlink:to="lab_cik0001563922_CommonStockSharesOtherCapitalActivity" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f7115-c6fc-76f6-99cf-2f5c1eca453d_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Maximum borrowing capacity</link:label>
    <link:label id="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Maximum Borrowing Capacity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_OYARosewoodHoldingsLLCPreviouslyOYASolarB1IntermediateHoldcoLLCOYAMember_019f7115-c671-78ee-9ac4-ca09d485ab93_terseLabel_en-US" xlink:label="lab_cik0001563922_OYARosewoodHoldingsLLCPreviouslyOYASolarB1IntermediateHoldcoLLCOYAMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">OYA</link:label>
    <link:label id="lab_cik0001563922_OYARosewoodHoldingsLLCPreviouslyOYASolarB1IntermediateHoldcoLLCOYAMember_label_en-US" xlink:label="lab_cik0001563922_OYARosewoodHoldingsLLCPreviouslyOYASolarB1IntermediateHoldcoLLCOYAMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">OYA-Rosewood Holdings LLC, previously OYA Solar B1 Intermediate Holdco LLC ("OYA") [Member]</link:label>
    <link:label id="lab_cik0001563922_OYARosewoodHoldingsLLCPreviouslyOYASolarB1IntermediateHoldcoLLCOYAMember_documentation_en-US" xlink:label="lab_cik0001563922_OYARosewoodHoldingsLLCPreviouslyOYASolarB1IntermediateHoldcoLLCOYAMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">OYA-Rosewood Holdings LLC, previously OYA Solar B1 Intermediate Holdco LLC ("OYA")</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OYARosewoodHoldingsLLCPreviouslyOYASolarB1IntermediateHoldcoLLCOYAMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OYARosewoodHoldingsLLCPreviouslyOYASolarB1IntermediateHoldcoLLCOYAMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_OYARosewoodHoldingsLLCPreviouslyOYASolarB1IntermediateHoldcoLLCOYAMember" xlink:to="lab_cik0001563922_OYARosewoodHoldingsLLCPreviouslyOYASolarB1IntermediateHoldcoLLCOYAMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_EagleValleyCleanEnergyEVCELLCMember_019f7115-c76d-7a3a-b3f8-db73d1eefbd0_terseLabel_en-US" xlink:label="lab_cik0001563922_EagleValleyCleanEnergyEVCELLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Eagle Valley Clean Energy LLC</link:label>
    <link:label id="lab_cik0001563922_EagleValleyCleanEnergyEVCELLCMember_label_en-US" xlink:label="lab_cik0001563922_EagleValleyCleanEnergyEVCELLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Eagle Valley Clean Energy ("EVCE") LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_EagleValleyCleanEnergyEVCELLCMember_documentation_en-US" xlink:label="lab_cik0001563922_EagleValleyCleanEnergyEVCELLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Eagle Valley Clean Energy ("EVCE") LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_EagleValleyCleanEnergyEVCELLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_EagleValleyCleanEnergyEVCELLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_EagleValleyCleanEnergyEVCELLCMember" xlink:to="lab_cik0001563922_EagleValleyCleanEnergyEVCELLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_019f7115-c5e8-7f7b-8084-1aeb98d0c336_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Issuance of common shares under distribution reinvestment plan (in shares)</link:label>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_019f7115-c5e8-746a-b777-08c348f8867c_verboseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Shares issued through reinvestment of distributions (in shares)</link:label>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Issued During Period, Shares, Dividend Reinvestment Plan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StockRepurchasedDuringPeriodShares_019f7115-c6fc-72a1-94fb-0a0f6dac4770_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_StockRepurchasedDuringPeriodShares" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Repurchases of common shares (in shares)</link:label>
    <link:label id="lab_us-gaap_StockRepurchasedDuringPeriodShares_019f7115-c6fc-70dd-8c71-ff553700c596_negatedLabel_en-US" xlink:label="lab_us-gaap_StockRepurchasedDuringPeriodShares" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Shares repurchased (in shares)</link:label>
    <link:label id="lab_us-gaap_StockRepurchasedDuringPeriodShares_label_en-US" xlink:label="lab_us-gaap_StockRepurchasedDuringPeriodShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Repurchased During Period, Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockRepurchasedDuringPeriodShares" xlink:to="lab_us-gaap_StockRepurchasedDuringPeriodShares" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SolarAndWindGeneratingPlantsMember_019f7115-c76d-74eb-bb66-67ac474864e2_terseLabel_en-US" xlink:label="lab_cik0001563922_SolarAndWindGeneratingPlantsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Solar And Wind Generating Plants</link:label>
    <link:label id="lab_cik0001563922_SolarAndWindGeneratingPlantsMember_label_en-US" xlink:label="lab_cik0001563922_SolarAndWindGeneratingPlantsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Solar And Wind Generating Plants [Member]</link:label>
    <link:label id="lab_cik0001563922_SolarAndWindGeneratingPlantsMember_documentation_en-US" xlink:label="lab_cik0001563922_SolarAndWindGeneratingPlantsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Solar And Wind Generating Plants</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SolarAndWindGeneratingPlantsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SolarAndWindGeneratingPlantsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SolarAndWindGeneratingPlantsMember" xlink:to="lab_cik0001563922_SolarAndWindGeneratingPlantsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingExpensesAbstract_019f7115-c555-7996-8833-f32f95740d69_verboseLabel_en-US" xlink:label="lab_us-gaap_OperatingExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Operating expenses</link:label>
    <link:label id="lab_us-gaap_OperatingExpensesAbstract_019f7115-c555-7c57-8c44-a7e2700d2119_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating expenses</link:label>
    <link:label id="lab_us-gaap_OperatingExpensesAbstract_label_en-US" xlink:label="lab_us-gaap_OperatingExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Expenses [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingExpensesAbstract" xlink:to="lab_us-gaap_OperatingExpensesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PrepaidExpenseCurrent_019f7115-c554-7f58-8144-659f8090b989_terseLabel_en-US" xlink:label="lab_us-gaap_PrepaidExpenseCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Prepaid expenses</link:label>
    <link:label id="lab_us-gaap_PrepaidExpenseCurrent_label_en-US" xlink:label="lab_us-gaap_PrepaidExpenseCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Prepaid Expense, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PrepaidExpenseCurrent" xlink:to="lab_us-gaap_PrepaidExpenseCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherLiabilitiesCurrent_019f7115-c76d-7439-9042-60ea2adbdb11_terseLabel_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other current liabilities</link:label>
    <link:label id="lab_us-gaap_OtherLiabilitiesCurrent_label_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Liabilities, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherLiabilitiesCurrent" xlink:to="lab_us-gaap_OtherLiabilitiesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ChannelPartnerRelationshipsAndTrademarksMember_019f7115-c555-7b65-9d73-51f6af32e724_terseLabel_en-US" xlink:label="lab_cik0001563922_ChannelPartnerRelationshipsAndTrademarksMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Channel Partner Relationships and Trademarks</link:label>
    <link:label id="lab_cik0001563922_ChannelPartnerRelationshipsAndTrademarksMember_label_en-US" xlink:label="lab_cik0001563922_ChannelPartnerRelationshipsAndTrademarksMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Channel Partner Relationships And Trademarks [Member]</link:label>
    <link:label id="lab_cik0001563922_ChannelPartnerRelationshipsAndTrademarksMember_documentation_en-US" xlink:label="lab_cik0001563922_ChannelPartnerRelationshipsAndTrademarksMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Channel Partner Relationships And Trademarks</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ChannelPartnerRelationshipsAndTrademarksMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ChannelPartnerRelationshipsAndTrademarksMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ChannelPartnerRelationshipsAndTrademarksMember" xlink:to="lab_cik0001563922_ChannelPartnerRelationshipsAndTrademarksMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RedeemableCommonSharesClassOfPIMember_019f7115-c555-745a-9dfd-b878dde19858_terseLabel_en-US" xlink:label="lab_cik0001563922_RedeemableCommonSharesClassOfPIMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Redeemable Common Shares, Common Class of P-I</link:label>
    <link:label id="lab_cik0001563922_RedeemableCommonSharesClassOfPIMember_label_en-US" xlink:label="lab_cik0001563922_RedeemableCommonSharesClassOfPIMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Redeemable Common Shares, Class Of P-I [Member]</link:label>
    <link:label id="lab_cik0001563922_RedeemableCommonSharesClassOfPIMember_documentation_en-US" xlink:label="lab_cik0001563922_RedeemableCommonSharesClassOfPIMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Redeemable Common Shares, Class Of P-I</link:label>
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    <link:label id="lab_us-gaap_StatementLineItems_label_en-US" xlink:label="lab_us-gaap_StatementLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement [Line Items]</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsNoncurrent" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FailedSaleLeasebackTransactionOriginationCostsNoncurrent"/>
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    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
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    <link:label id="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue_019f7115-c671-74f5-a635-72b95b216ba7_terseLabel_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash and cash equivalents</link:label>
    <link:label id="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue_label_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash and Cash Equivalent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
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    <link:label id="lab_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_label_en-US" xlink:label="lab_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Measurement Inputs and Valuation Techniques [Table]</link:label>
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    <link:label id="lab_us-gaap_SubsequentEventLineItems_label_en-US" xlink:label="lab_us-gaap_SubsequentEventLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems"/>
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    <link:label id="lab_cik0001563922_DebtInstrumentPrepaymentPremiumDiscountPercentage_documentation_en-US" xlink:label="lab_cik0001563922_DebtInstrumentPrepaymentPremiumDiscountPercentage" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Prepayment Premium (Discount), Percentage</link:label>
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    <link:label id="lab_cik0001563922_ECCAMember_019f7115-c554-7da3-bcf7-7e2baa64bf04_terseLabel_en-US" xlink:label="lab_cik0001563922_ECCAMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">ECCA</link:label>
    <link:label id="lab_cik0001563922_ECCAMember_label_en-US" xlink:label="lab_cik0001563922_ECCAMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">ECCA [Member]</link:label>
    <link:label id="lab_cik0001563922_ECCAMember_documentation_en-US" xlink:label="lab_cik0001563922_ECCAMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">ECCA</link:label>
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    <link:label id="lab_us-gaap_CommonStockMember_019f7115-c671-779d-8386-c57fd7d20a63_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common Stock</link:label>
    <link:label id="lab_us-gaap_CommonStockMember_label_en-US" xlink:label="lab_us-gaap_CommonStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock [Member]</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f7115-c554-74b3-89d3-6c41637a20d6_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Vested (in shares)</link:label>
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    <link:label id="lab_cik0001563922_OperatingLeaseAssetsAndLiabilitiesLesseeAbstract_019f7115-c76d-7a7a-9875-198df9553ba3_terseLabel_en-US" xlink:label="lab_cik0001563922_OperatingLeaseAssetsAndLiabilitiesLesseeAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating leases</link:label>
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    <link:label id="lab_cik0001563922_OperatingLeaseAssetsAndLiabilitiesLesseeAbstract_documentation_en-US" xlink:label="lab_cik0001563922_OperatingLeaseAssetsAndLiabilitiesLesseeAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Operating Lease, Assets And Liabilities, Lessee</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OperatingLeaseAssetsAndLiabilitiesLesseeAbstract" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OperatingLeaseAssetsAndLiabilitiesLesseeAbstract"/>
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    <link:label id="lab_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_019f7115-c671-7b00-998d-0e04c80f7fd7_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Finance Leases</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
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    <link:label id="lab_us-gaap_UnrealizedGainLossOnInvestments_019f7115-c555-7a92-86b3-917bc7c7ba2f_netLabel_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnInvestments" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xml:lang="en-US">Change in fair value of investments, net</link:label>
    <link:label id="lab_us-gaap_UnrealizedGainLossOnInvestments_019f7115-c555-7370-bdcb-bc1c77d090cc_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnInvestments" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Change in fair value of investments, net</link:label>
    <link:label id="lab_us-gaap_UnrealizedGainLossOnInvestments_019f7115-c555-7f84-8e2e-72d879acc760_terseLabel_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnInvestments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total Change in fair value of investments, net</link:label>
    <link:label id="lab_us-gaap_UnrealizedGainLossOnInvestments_019f7115-c555-74c7-a92b-725fdd5eebcc_verboseLabel_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnInvestments" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Change in fair value of investments, net</link:label>
    <link:label id="lab_us-gaap_UnrealizedGainLossOnInvestments_label_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnInvestments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Unrealized Gain (Loss) on Investments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UnrealizedGainLossOnInvestments" xlink:to="lab_us-gaap_UnrealizedGainLossOnInvestments" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SignificantAccountingPoliciesTextBlock_019f7115-c5e8-7e3a-80ae-0ad94255b136_terseLabel_en-US" xlink:label="lab_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Significant Accounting Policies</link:label>
    <link:label id="lab_us-gaap_SignificantAccountingPoliciesTextBlock_label_en-US" xlink:label="lab_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Significant Accounting Policies [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SignificantAccountingPoliciesTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="lab_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_RangeMember_019f7115-c5e8-7735-9c0d-e1a894519d7e_terseLabel_en-US" xlink:label="lab_srt_RangeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statistical Measurement [Domain]</link:label>
    <link:label id="lab_srt_RangeMember_label_en-US" xlink:label="lab_srt_RangeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statistical Measurement [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RangeMember" xlink:to="lab_srt_RangeMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NoncontrollingInterestDecreaseFromSubsidiaryEquityIssuanceSyndicationCosts_019f7115-c76d-7889-876b-13c08b8bcb4c_negatedLabel_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestDecreaseFromSubsidiaryEquityIssuanceSyndicationCosts" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Syndication costs</link:label>
    <link:label id="lab_cik0001563922_NoncontrollingInterestDecreaseFromSubsidiaryEquityIssuanceSyndicationCosts_label_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestDecreaseFromSubsidiaryEquityIssuanceSyndicationCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Decrease From Subsidiary Equity Issuance, Syndication Costs</link:label>
    <link:label id="lab_cik0001563922_NoncontrollingInterestDecreaseFromSubsidiaryEquityIssuanceSyndicationCosts_documentation_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestDecreaseFromSubsidiaryEquityIssuanceSyndicationCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Decrease From Subsidiary Equity Issuance, Syndication Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NoncontrollingInterestDecreaseFromSubsidiaryEquityIssuanceSyndicationCosts" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NoncontrollingInterestDecreaseFromSubsidiaryEquityIssuanceSyndicationCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NoncontrollingInterestDecreaseFromSubsidiaryEquityIssuanceSyndicationCosts" xlink:to="lab_cik0001563922_NoncontrollingInterestDecreaseFromSubsidiaryEquityIssuanceSyndicationCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherCurrentAssetsMember_019f7115-c5e8-7642-aa61-e782d89b1571_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCurrentAssetsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other Current Assets</link:label>
    <link:label id="lab_us-gaap_OtherCurrentAssetsMember_label_en-US" xlink:label="lab_us-gaap_OtherCurrentAssetsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Current Assets [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentAssetsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCurrentAssetsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCurrentAssetsMember" xlink:to="lab_us-gaap_OtherCurrentAssetsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesContractRetirements_019f7115-c554-7d70-a9a7-8a30915239da_terseLabel_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesContractRetirements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Out-of-market contracts, intangible liabilities, contract retirements</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesContractRetirements_label_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesContractRetirements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Out-Of-Market Contracts, Intangible Liabilities, Contract Retirements</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesContractRetirements_documentation_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesContractRetirements" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Out-Of-Market Contracts, Intangible Liabilities, Contract Retirements</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesContractRetirements" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OutOfMarketContractsIntangibleLiabilitiesContractRetirements"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesContractRetirements" xlink:to="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesContractRetirements" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList_019f7115-c554-7756-96b7-d62d70318b07_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList" xlink:to="lab_us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FinanceLeaseCost_019f7115-c5e8-7956-b1cb-f8b2f5757554_totalLabel_en-US" xlink:label="lab_cik0001563922_FinanceLeaseCost" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total finance lease cost</link:label>
    <link:label id="lab_cik0001563922_FinanceLeaseCost_label_en-US" xlink:label="lab_cik0001563922_FinanceLeaseCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Cost</link:label>
    <link:label id="lab_cik0001563922_FinanceLeaseCost_documentation_en-US" xlink:label="lab_cik0001563922_FinanceLeaseCost" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Finance Lease, Cost</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FinanceLeaseCost" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FinanceLeaseCost"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FinanceLeaseCost" xlink:to="lab_cik0001563922_FinanceLeaseCost" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RestrictedCashCurrent_019f7115-c6fc-7e97-9241-37a62985c49a_terseLabel_en-US" xlink:label="lab_us-gaap_RestrictedCashCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Restricted cash, current</link:label>
    <link:label id="lab_us-gaap_RestrictedCashCurrent_label_en-US" xlink:label="lab_us-gaap_RestrictedCashCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restricted Cash, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestrictedCashCurrent" xlink:to="lab_us-gaap_RestrictedCashCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses_019f7115-c671-7eca-bea0-ff0494f1a9b4_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impairment of goodwill</link:label>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" xlink:to="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaim_019f7115-c5e8-714a-83ed-985964ab4cc4_periodStartLabel_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaim" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Beginning balance</link:label>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaim_019f7115-c5e8-70a3-83db-29ad359613a6_periodEndLabel_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaim" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Ending balance</link:label>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaim_label_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaim" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Bankruptcy Claim</link:label>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaim_documentation_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaim" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Bankruptcy Claim</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaim" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisBankruptcyClaim"/>
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    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019f7115-c555-755f-a85d-2b7b75024269_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]</link:label>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
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    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsPPAUnfavorableContractMember_019f7115-c671-7045-b5a6-a266608d1121_terseLabel_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsPPAUnfavorableContractMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">PPA contracts</link:label>
    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsPPAUnfavorableContractMember_label_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsPPAUnfavorableContractMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Power Purchase Agreements ("PPA"), Unfavorable Contract [Member]</link:label>
    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsPPAUnfavorableContractMember_documentation_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsPPAUnfavorableContractMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Power Purchase Agreements ("PPA"), Unfavorable Contract</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PowerPurchaseAgreementsPPAUnfavorableContractMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PowerPurchaseAgreementsPPAUnfavorableContractMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PowerPurchaseAgreementsPPAUnfavorableContractMember" xlink:to="lab_cik0001563922_PowerPurchaseAgreementsPPAUnfavorableContractMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueByAssetClassAxis_019f7115-c6fc-7470-a170-455543d07c97_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByAssetClassAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset Class [Axis]</link:label>
    <link:label id="lab_us-gaap_FairValueByAssetClassAxis_label_en-US" xlink:label="lab_us-gaap_FairValueByAssetClassAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Class [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueByAssetClassAxis" xlink:to="lab_us-gaap_FairValueByAssetClassAxis" xlink:type="arc" order="1"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock"/>
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    <link:label id="lab_us-gaap_LeasesAbstract_label_en-US" xlink:label="lab_us-gaap_LeasesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Leases [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeasesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeasesAbstract"/>
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    <link:label id="lab_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_019f7115-c6fc-7771-bf1a-701657ecc7fc_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Equity consideration (in shares)</link:label>
    <link:label id="lab_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
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    <link:label id="lab_us-gaap_DividendsDeclaredTableTextBlock_019f7115-c671-7a62-8e46-862a361eda8b_terseLabel_en-US" xlink:label="lab_us-gaap_DividendsDeclaredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Distributions Declared</link:label>
    <link:label id="lab_us-gaap_DividendsDeclaredTableTextBlock_label_en-US" xlink:label="lab_us-gaap_DividendsDeclaredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dividends Declared [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDeclaredTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsDeclaredTableTextBlock"/>
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    <link:label id="lab_cik0001563922_CeladonManagerLLCMember_019f7115-c6fc-739f-b872-f1374a48ae4d_terseLabel_en-US" xlink:label="lab_cik0001563922_CeladonManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Celadon Manager LLC</link:label>
    <link:label id="lab_cik0001563922_CeladonManagerLLCMember_label_en-US" xlink:label="lab_cik0001563922_CeladonManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Celadon Manager LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_CeladonManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_CeladonManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Celadon Manager LLC</link:label>
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    <link:label id="lab_cik0001563922_MidwayIIIManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_MidwayIIIManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Midway III Manager LLC</link:label>
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    <link:label id="lab_cik0001563922_NumberOfPurchaseAgreements_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfPurchaseAgreements" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number Of Purchase Agreements</link:label>
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    <link:label id="lab_us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis_019f7115-c5e8-7478-9737-16de031d0255_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Category of Item Purchased [Axis]</link:label>
    <link:label id="lab_us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis_label_en-US" xlink:label="lab_us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Category of Item Purchased [Axis]</link:label>
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    <link:label id="lab_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_019f7115-c6fc-707e-a73e-92c4e52cf1c7_terseLabel_en-US" xlink:label="lab_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Primary Beneficiary</link:label>
    <link:label id="lab_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_label_en-US" xlink:label="lab_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Primary Beneficiary [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember"/>
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    <link:label id="lab_us-gaap_LitigationSettlementAmountAwardedFromOtherParty_label_en-US" xlink:label="lab_us-gaap_LitigationSettlementAmountAwardedFromOtherParty" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Litigation Settlement, Amount Awarded from Other Party</link:label>
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    <link:label id="lab_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts and Financing Receivables [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
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    <link:label id="lab_cik0001563922_StockTransferredDuringPeriodShares_label_en-US" xlink:label="lab_cik0001563922_StockTransferredDuringPeriodShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Transferred During Period, Shares</link:label>
    <link:label id="lab_cik0001563922_StockTransferredDuringPeriodShares_documentation_en-US" xlink:label="lab_cik0001563922_StockTransferredDuringPeriodShares" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Stock Transferred During Period, Shares</link:label>
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    <link:label id="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfCommonSharesIssuedAndOutstandingForIssuanceToEmployeesAndNonEmployeeDirectors_label_en-US" xlink:label="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfCommonSharesIssuedAndOutstandingForIssuanceToEmployeesAndNonEmployeeDirectors" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Percentage Of Common Shares Issued And Outstanding For Issuance To Employees And Non-Employee Directors</link:label>
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    <link:label id="lab_us-gaap_PaymentsToAcquireEquityMethodInvestments_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments to Acquire Equity Method Investments</link:label>
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    <link:label id="lab_us-gaap_AllocatedShareBasedCompensationExpense_019f7115-c554-7652-9b77-688b24f7b4bc_terseLabel_en-US" xlink:label="lab_us-gaap_AllocatedShareBasedCompensationExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based compensation expense</link:label>
    <link:label id="lab_us-gaap_AllocatedShareBasedCompensationExpense_label_en-US" xlink:label="lab_us-gaap_AllocatedShareBasedCompensationExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement, Expense</link:label>
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    <link:label id="lab_us-gaap_HedgingDesignationDomain_label_en-US" xlink:label="lab_us-gaap_HedgingDesignationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Hedging Designation [Domain]</link:label>
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    <link:label id="lab_us-gaap_ConcentrationRiskByBenchmarkAxis_019f7115-c671-73a9-932b-3113c785506b_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Concentration Risk Benchmark [Axis]</link:label>
    <link:label id="lab_us-gaap_ConcentrationRiskByBenchmarkAxis_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk Benchmark [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="lab_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrentAbstract_019f7115-c6fc-7d0b-835e-43602771332c_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Noncurrent liabilities:</link:label>
    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrentAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrentAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrentAbstract" xlink:to="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_TemporaryEquityNetIncome_019f7115-c671-7ded-bff4-8969d64b0038_terseLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquityNetIncome" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net income (loss)</link:label>
    <link:label id="lab_us-gaap_TemporaryEquityNetIncome_label_en-US" xlink:label="lab_us-gaap_TemporaryEquityNetIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Net Income</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityNetIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityNetIncome"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquityNetIncome" xlink:to="lab_us-gaap_TemporaryEquityNetIncome" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredTaxAssetsOther_019f7115-c5e8-7036-8e36-3852a74c7837_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:label id="lab_us-gaap_DeferredTaxAssetsOther_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Other</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOther" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOther"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxAssetsOther" xlink:to="lab_us-gaap_DeferredTaxAssetsOther" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentInterestRateIncreaseDecrease_019f7115-c671-7321-b78d-7098c1b2661f_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateIncreaseDecrease" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Increase to interest rate</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentInterestRateIncreaseDecrease_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateIncreaseDecrease" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Interest Rate, Increase (Decrease)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateIncreaseDecrease" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateIncreaseDecrease"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentInterestRateIncreaseDecrease" xlink:to="lab_us-gaap_DebtInstrumentInterestRateIncreaseDecrease" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccountingPoliciesAbstract_019f7115-c5e8-79cc-9648-c134ab314f1c_terseLabel_en-US" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounting Policies [Abstract]</link:label>
    <link:label id="lab_us-gaap_AccountingPoliciesAbstract_label_en-US" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounting Policies [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountingPoliciesAbstract" xlink:to="lab_us-gaap_AccountingPoliciesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ParticipatingEarnoutSharesMember_019f7115-c5e8-74cc-8e43-5c7c652bd44b_terseLabel_en-US" xlink:label="lab_cik0001563922_ParticipatingEarnoutSharesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earnout Share reclassification to permanent equity</link:label>
    <link:label id="lab_cik0001563922_ParticipatingEarnoutSharesMember_label_en-US" xlink:label="lab_cik0001563922_ParticipatingEarnoutSharesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Participating Earnout Shares [Member]</link:label>
    <link:label id="lab_cik0001563922_ParticipatingEarnoutSharesMember_documentation_en-US" xlink:label="lab_cik0001563922_ParticipatingEarnoutSharesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Participating Earnout Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ParticipatingEarnoutSharesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ParticipatingEarnoutSharesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ParticipatingEarnoutSharesMember" xlink:to="lab_cik0001563922_ParticipatingEarnoutSharesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SegoLilyManagerLLCMember_019f7115-c555-7b54-98b0-ff7be92a44a7_terseLabel_en-US" xlink:label="lab_cik0001563922_SegoLilyManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Sego Lily Solar Manager LLC</link:label>
    <link:label id="lab_cik0001563922_SegoLilyManagerLLCMember_label_en-US" xlink:label="lab_cik0001563922_SegoLilyManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sego Lily Manager LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_SegoLilyManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_SegoLilyManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sego Lily Manager LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SegoLilyManagerLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SegoLilyManagerLLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SegoLilyManagerLLCMember" xlink:to="lab_cik0001563922_SegoLilyManagerLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_019f7115-c555-7538-8645-4be49f5cb3e0_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Maturity of Operating Lease</link:label>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetAcquisitionTextBlock_019f7115-c5e8-7bcc-b3da-e4737f7e92d8_terseLabel_en-US" xlink:label="lab_us-gaap_AssetAcquisitionTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Acquisitions and Divestitures</link:label>
    <link:label id="lab_us-gaap_AssetAcquisitionTextBlock_label_en-US" xlink:label="lab_us-gaap_AssetAcquisitionTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Acquisition [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetAcquisitionTextBlock" xlink:to="lab_us-gaap_AssetAcquisitionTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConcentrationRiskTypeDomain_019f7115-c671-7d01-a267-b46e16290026_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Concentration Risk Type [Domain]</link:label>
    <link:label id="lab_us-gaap_ConcentrationRiskTypeDomain_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk Type [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain" xlink:to="lab_us-gaap_ConcentrationRiskTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FederalTaxCreditCarryforwardsMember_019f7115-c555-73d8-b2e4-3a717be00f45_terseLabel_en-US" xlink:label="lab_cik0001563922_FederalTaxCreditCarryforwardsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Federal Tax Credit Carryforwards</link:label>
    <link:label id="lab_cik0001563922_FederalTaxCreditCarryforwardsMember_label_en-US" xlink:label="lab_cik0001563922_FederalTaxCreditCarryforwardsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Federal Tax Credit Carryforwards [Member]</link:label>
    <link:label id="lab_cik0001563922_FederalTaxCreditCarryforwardsMember_documentation_en-US" xlink:label="lab_cik0001563922_FederalTaxCreditCarryforwardsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Federal Tax Credit Carryforwards</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FederalTaxCreditCarryforwardsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FederalTaxCreditCarryforwardsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FederalTaxCreditCarryforwardsMember" xlink:to="lab_cik0001563922_FederalTaxCreditCarryforwardsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PurchaseObligationPowerOfSolarPanel_019f7115-c6fc-7ff4-ba01-c45e3f7da42b_terseLabel_en-US" xlink:label="lab_cik0001563922_PurchaseObligationPowerOfSolarPanel" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Power of solar panel (in megawatts)</link:label>
    <link:label id="lab_cik0001563922_PurchaseObligationPowerOfSolarPanel_label_en-US" xlink:label="lab_cik0001563922_PurchaseObligationPowerOfSolarPanel" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Purchase Obligation, Power Of Solar Panel</link:label>
    <link:label id="lab_cik0001563922_PurchaseObligationPowerOfSolarPanel_documentation_en-US" xlink:label="lab_cik0001563922_PurchaseObligationPowerOfSolarPanel" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Purchase Obligation, Power Of Solar Panel</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PurchaseObligationPowerOfSolarPanel" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PurchaseObligationPowerOfSolarPanel"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PurchaseObligationPowerOfSolarPanel" xlink:to="lab_cik0001563922_PurchaseObligationPowerOfSolarPanel" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiabilityReturnOfCapital_019f7115-c76d-79a0-aa0d-c3b52c5da1a7_terseLabel_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiabilityReturnOfCapital" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Return of capital</link:label>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiabilityReturnOfCapital_label_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiabilityReturnOfCapital" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Net Asset (Liability), Return Of Capital</link:label>
    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiabilityReturnOfCapital_documentation_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiabilityReturnOfCapital" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Net Asset (Liability), Return Of Capital</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiabilityReturnOfCapital" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiabilityReturnOfCapital"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiabilityReturnOfCapital" xlink:to="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisNetAssetLiabilityReturnOfCapital" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseLiability_019f7115-c5e8-7a33-89d7-fff0291d6490_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Present value of lease liabilities</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLiability_019f7115-c5e8-7b39-829d-c42d5a51bfdc_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Total operating lease liabilities</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLiability_019f7115-c5e8-79eb-8a59-27ab3fe5014d_verboseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Present value of lease liabilities</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLiability_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiability" xlink:to="lab_us-gaap_OperatingLeaseLiability" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_StockholdersEquityDeferredShareholderServicingFees_019f7115-c671-7cd6-9eae-6a68c7848f6a_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_StockholdersEquityDeferredShareholderServicingFees" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Deferred shareholder servicing fees</link:label>
    <link:label id="lab_cik0001563922_StockholdersEquityDeferredShareholderServicingFees_label_en-US" xlink:label="lab_cik0001563922_StockholdersEquityDeferredShareholderServicingFees" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stockholders Equity, Deferred Shareholder Servicing Fees</link:label>
    <link:label id="lab_cik0001563922_StockholdersEquityDeferredShareholderServicingFees_documentation_en-US" xlink:label="lab_cik0001563922_StockholdersEquityDeferredShareholderServicingFees" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Stockholders Equity, Deferred Shareholder Servicing Fees</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_StockholdersEquityDeferredShareholderServicingFees" xlink:href="cik0001563922-20260810.xsd#cik0001563922_StockholdersEquityDeferredShareholderServicingFees"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_StockholdersEquityDeferredShareholderServicingFees" xlink:to="lab_cik0001563922_StockholdersEquityDeferredShareholderServicingFees" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LineOfCreditFacilityLenderDomain_019f7115-c76d-7f30-a4f8-744ac0240b2a_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityLenderDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Lender [Domain]</link:label>
    <link:label id="lab_us-gaap_LineOfCreditFacilityLenderDomain_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityLenderDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Lender [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain" xlink:to="lab_us-gaap_LineOfCreditFacilityLenderDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive_019f7115-c555-7532-8e25-9ac6269f8b87_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Thereafter</link:label>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, after Rolling Year Five</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessCombinationDisclosureTextBlock_019f7115-c5e8-7d95-ba9c-f58a866e8c05_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Acquisitions and Divestitures</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Combination [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:to="lab_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DepreciationAndAmortization_019f7115-c671-75bd-b45d-a5a0dac55db9_terseLabel_en-US" xlink:label="lab_us-gaap_DepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Depreciation, amortization and accretion</link:label>
    <link:label id="lab_us-gaap_DepreciationAndAmortization_019f7115-c671-720a-ba08-b732163e32ee_verboseLabel_en-US" xlink:label="lab_us-gaap_DepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Depreciation, amortization and accretion</link:label>
    <link:label id="lab_us-gaap_DepreciationAndAmortization_label_en-US" xlink:label="lab_us-gaap_DepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Depreciation, Depletion and Amortization, Nonproduction</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DepreciationAndAmortization" xlink:to="lab_us-gaap_DepreciationAndAmortization" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseRightOfUseAssetAmortization_019f7115-c6fc-7057-9e50-dbe1c2d5411b_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amortization of right-of-use assets</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseRightOfUseAssetAmortization_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Right-of-Use Asset, Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetAmortization"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:to="lab_us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherLiabilitiesNoncurrent_019f7115-c671-7d9f-a31b-b356d9dbd0d6_terseLabel_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other noncurrent liabilities</link:label>
    <link:label id="lab_us-gaap_OtherLiabilitiesNoncurrent_label_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Liabilities, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherLiabilitiesNoncurrent" xlink:to="lab_us-gaap_OtherLiabilitiesNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackFinancingAndDeferredInvestmentTaxCreditGainCurrentPortionAbstract_019f7115-c5e8-7773-91ce-14366d7da8f5_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackFinancingAndDeferredInvestmentTaxCreditGainCurrentPortionAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Sale Leaseback Financing and Deferred Investment Tax Credit Gain, Current Portion [Abstract]</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackFinancingAndDeferredInvestmentTaxCreditGainCurrentPortionAbstract_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackFinancingAndDeferredInvestmentTaxCreditGainCurrentPortionAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Financing and Deferred Investment Tax Credit Gain, Current Portion [Abstract]</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackFinancingAndDeferredInvestmentTaxCreditGainCurrentPortionAbstract_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackFinancingAndDeferredInvestmentTaxCreditGainCurrentPortionAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Financing and Deferred Investment Tax Credit Gain, Current Portion</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackFinancingAndDeferredInvestmentTaxCreditGainCurrentPortionAbstract" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackFinancingAndDeferredInvestmentTaxCreditGainCurrentPortionAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackFinancingAndDeferredInvestmentTaxCreditGainCurrentPortionAbstract" xlink:to="lab_cik0001563922_SaleLeasebackFinancingAndDeferredInvestmentTaxCreditGainCurrentPortionAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ParentCompanyGuaranteesMember_019f7115-c5e8-77ce-9b5b-a5d697653bb0_terseLabel_en-US" xlink:label="lab_cik0001563922_ParentCompanyGuaranteesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Parent Company Guarantees</link:label>
    <link:label id="lab_cik0001563922_ParentCompanyGuaranteesMember_label_en-US" xlink:label="lab_cik0001563922_ParentCompanyGuaranteesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Parent Company Guarantees [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ParentCompanyGuaranteesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ParentCompanyGuaranteesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ParentCompanyGuaranteesMember" xlink:to="lab_cik0001563922_ParentCompanyGuaranteesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019f7115-c6fc-7115-b847-71b71edfb2b7_verboseLabel_en-US" xlink:label="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Investments at fair value</link:label>
    <link:label id="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_label_en-US" xlink:label="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
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    <link:label id="lab_cik0001563922_NoncontrollingInterestDecreaseFromSaleOfParentEquityInterest_019f7115-c554-7960-95c5-b0d893dfd8d9_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestDecreaseFromSaleOfParentEquityInterest" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Noncontrolling interests transferred due to sale of projects</link:label>
    <link:label id="lab_cik0001563922_NoncontrollingInterestDecreaseFromSaleOfParentEquityInterest_label_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestDecreaseFromSaleOfParentEquityInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest Decrease From Sale Of Parent Equity Interest</link:label>
    <link:label id="lab_cik0001563922_NoncontrollingInterestDecreaseFromSaleOfParentEquityInterest_documentation_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestDecreaseFromSaleOfParentEquityInterest" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest Decrease From Sale Of Parent Equity Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NoncontrollingInterestDecreaseFromSaleOfParentEquityInterest" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NoncontrollingInterestDecreaseFromSaleOfParentEquityInterest"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NoncontrollingInterestDecreaseFromSaleOfParentEquityInterest" xlink:to="lab_cik0001563922_NoncontrollingInterestDecreaseFromSaleOfParentEquityInterest" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity_019f7115-c76d-743d-a56e-44fbc2b0d792_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Difference between carrying amount and consideration paid</link:label>
    <link:label id="lab_us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity_label_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Method Investment, Difference Between Carrying Amount and Underlying Equity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity" xlink:to="lab_us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_GoodwillImpairmentLoss_019f7115-c5e8-7e15-a958-7570589245e0_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impairment of goodwill</link:label>
    <link:label id="lab_us-gaap_GoodwillImpairmentLoss_label_en-US" xlink:label="lab_us-gaap_GoodwillImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Goodwill, Impairment Loss</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GoodwillImpairmentLoss" xlink:to="lab_us-gaap_GoodwillImpairmentLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfVariableInterestEntitiesTable_019f7115-c5e8-7f93-a16a-022c8c63c3ea_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfVariableInterestEntitiesTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Interest Entity [Table]</link:label>
    <link:label id="lab_us-gaap_ScheduleOfVariableInterestEntitiesTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfVariableInterestEntitiesTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entity [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable" xlink:to="lab_us-gaap_ScheduleOfVariableInterestEntitiesTable" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromBuyoutOfNoncontrollingInterest_019f7115-c554-7d4a-9b7d-f876d4e99308_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromBuyoutOfNoncontrollingInterest" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Buyout of noncontrolling interests</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromBuyoutOfNoncontrollingInterest_label_en-US" xlink:label="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromBuyoutOfNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Noncontrolling Interest, Decrease From Buyout Of Noncontrolling Interest</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromBuyoutOfNoncontrollingInterest_documentation_en-US" xlink:label="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromBuyoutOfNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Temporary Equity, Noncontrolling Interest, Decrease From Buyout Of Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromBuyoutOfNoncontrollingInterest" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromBuyoutOfNoncontrollingInterest"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromBuyoutOfNoncontrollingInterest" xlink:to="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromBuyoutOfNoncontrollingInterest" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_VariableInterestEntityNameDomain_019f7115-c555-79ff-94d0-9ff2a48ff502_terseLabel_en-US" xlink:label="lab_cik0001563922_VariableInterestEntityNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Name [Domain]</link:label>
    <link:label id="lab_cik0001563922_VariableInterestEntityNameDomain_label_en-US" xlink:label="lab_cik0001563922_VariableInterestEntityNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Name [Domain]</link:label>
    <link:label id="lab_cik0001563922_VariableInterestEntityNameDomain_documentation_en-US" xlink:label="lab_cik0001563922_VariableInterestEntityNameDomain" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_VariableInterestEntityNameDomain" xlink:href="cik0001563922-20260810.xsd#cik0001563922_VariableInterestEntityNameDomain"/>
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    <link:label id="lab_us-gaap_StatementOfCashFlowsAbstract_019f7115-c6fc-715e-a58a-0305f0c3a0bf_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement of Cash Flows [Abstract]</link:label>
    <link:label id="lab_us-gaap_StatementOfCashFlowsAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Cash Flows [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfCashFlowsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfCashFlowsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract" xlink:to="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermDebtCurrent_019f7115-c671-7160-9686-2c424b13ca4d_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Current portion of long-term debt</link:label>
    <link:label id="lab_us-gaap_LongTermDebtCurrent_019f7115-c671-758b-83ab-c087a9661459_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtCurrent" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Less: Current portion of long-term debt</link:label>
    <link:label id="lab_us-gaap_LongTermDebtCurrent_label_en-US" xlink:label="lab_us-gaap_LongTermDebtCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Current Maturities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtCurrent" xlink:to="lab_us-gaap_LongTermDebtCurrent" xlink:type="arc" order="1"/>
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    <link:label id="lab_cik0001563922_SecuredDebtTrancheBMember_label_en-US" xlink:label="lab_cik0001563922_SecuredDebtTrancheBMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Secured Debt Tranche B [Member]</link:label>
    <link:label id="lab_cik0001563922_SecuredDebtTrancheBMember_documentation_en-US" xlink:label="lab_cik0001563922_SecuredDebtTrancheBMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Secured Debt Tranche B</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SecuredDebtTrancheBMember" xlink:to="lab_cik0001563922_SecuredDebtTrancheBMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueRecurringBasisUnobservableInputReconciliationAssetGainLossStatementOfIncomeExtensibleList_019f7115-c6fc-74c7-a305-ac3d37209b35_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueRecurringBasisUnobservableInputReconciliationAssetGainLossStatementOfIncomeExtensibleList" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]</link:label>
    <link:label id="lab_us-gaap_FairValueRecurringBasisUnobservableInputReconciliationAssetGainLossStatementOfIncomeExtensibleList_label_en-US" xlink:label="lab_us-gaap_FairValueRecurringBasisUnobservableInputReconciliationAssetGainLossStatementOfIncomeExtensibleList" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueRecurringBasisUnobservableInputReconciliationAssetGainLossStatementOfIncomeExtensibleList" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueRecurringBasisUnobservableInputReconciliationAssetGainLossStatementOfIncomeExtensibleList"/>
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    <link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTax_019f7115-c671-7824-a3e6-2e9bb8d17a18_totalLabel_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTax" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Comprehensive income (loss) attributable to Greenbacker Renewable Energy Company LLC</link:label>
    <link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTax_label_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Comprehensive Income (Loss), Net of Tax, Attributable to Parent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="lab_us-gaap_ComprehensiveIncomeNetOfTax" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MeasurementInputTypeAxis_019f7115-c555-7b09-ace8-5784e2a63681_terseLabel_en-US" xlink:label="lab_us-gaap_MeasurementInputTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Measurement Input Type [Axis]</link:label>
    <link:label id="lab_us-gaap_MeasurementInputTypeAxis_label_en-US" xlink:label="lab_us-gaap_MeasurementInputTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MeasurementInputTypeAxis" xlink:to="lab_us-gaap_MeasurementInputTypeAxis" xlink:type="arc" order="1"/>
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    <link:label id="lab_cik0001563922_VariableRateTimeframeAxis_label_en-US" xlink:label="lab_cik0001563922_VariableRateTimeframeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Rate, Timeframe [Axis]</link:label>
    <link:label id="lab_cik0001563922_VariableRateTimeframeAxis_documentation_en-US" xlink:label="lab_cik0001563922_VariableRateTimeframeAxis" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Variable Rate, Timeframe</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_VariableRateTimeframeAxis" xlink:href="cik0001563922-20260810.xsd#cik0001563922_VariableRateTimeframeAxis"/>
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    <link:label id="lab_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_019f7115-c5e8-7f1d-9c8b-a87cfa88b57d_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Disposal Group Name [Domain]</link:label>
    <link:label id="lab_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_label_en-US" xlink:label="lab_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:to="lab_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SecuredDebtMember_019f7115-c6fc-75af-bff3-aecd4af7de54_terseLabel_en-US" xlink:label="lab_us-gaap_SecuredDebtMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Secured Debt</link:label>
    <link:label id="lab_us-gaap_SecuredDebtMember_label_en-US" xlink:label="lab_us-gaap_SecuredDebtMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Secured Debt [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SecuredDebtMember" xlink:to="lab_us-gaap_SecuredDebtMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_019f7115-c6fc-73fd-adde-533d51c9c3b9_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Change in Fair Value of Contingent Consideration</link:label>
    <link:label id="lab_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_label_en-US" xlink:label="lab_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:to="lab_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent_019f7115-c6fc-7942-ad32-6bf811983b75_terseLabel_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Current portion of failed sale-leaseback financing and deferred ITC gain</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent_019f7115-c6fc-770f-b368-f63928c4fcf1_totalLabel_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Current portion of failed sale-leaseback financing and deferred ITC gain</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent_label_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Financing Obligation And Investment Tax Credit, Current</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent_documentation_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Financing Obligation And Investment Tax Credit, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent" xlink:to="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndInvestmentTaxCreditCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsForPostemploymentBenefits_019f7115-c6fc-7a9c-90b4-6b1381c5f775_terseLabel_en-US" xlink:label="lab_us-gaap_PaymentsForPostemploymentBenefits" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash severance</link:label>
    <link:label id="lab_us-gaap_PaymentsForPostemploymentBenefits_label_en-US" xlink:label="lab_us-gaap_PaymentsForPostemploymentBenefits" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments for Postemployment Benefits</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForPostemploymentBenefits" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForPostemploymentBenefits"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsForPostemploymentBenefits" xlink:to="lab_us-gaap_PaymentsForPostemploymentBenefits" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ClassOfStockLineItems_019f7115-c554-7a71-aaef-57a112f0f1e4_terseLabel_en-US" xlink:label="lab_us-gaap_ClassOfStockLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Stock [Line Items]</link:label>
    <link:label id="lab_us-gaap_ClassOfStockLineItems_label_en-US" xlink:label="lab_us-gaap_ClassOfStockLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Stock [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockLineItems"/>
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    <link:label id="lab_us-gaap_DeferredIncomeTaxLiabilitiesNet_019f7115-c5e8-7355-8424-f5e210669228_verboseLabel_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Deferred tax liabilities, net</link:label>
    <link:label id="lab_us-gaap_DeferredIncomeTaxLiabilitiesNet_label_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Income Tax Liabilities, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
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    <link:label id="lab_cik0001563922_BusinessCombinationContingentConsiderationShares_019f7115-c555-73a5-8d5e-dfed4385d9a6_terseLabel_en-US" xlink:label="lab_cik0001563922_BusinessCombinationContingentConsiderationShares" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earnout shares (in shares)</link:label>
    <link:label id="lab_cik0001563922_BusinessCombinationContingentConsiderationShares_label_en-US" xlink:label="lab_cik0001563922_BusinessCombinationContingentConsiderationShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Combination, Contingent Consideration, Shares</link:label>
    <link:label id="lab_cik0001563922_BusinessCombinationContingentConsiderationShares_documentation_en-US" xlink:label="lab_cik0001563922_BusinessCombinationContingentConsiderationShares" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Business Combination, Contingent Consideration, Shares</link:label>
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    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo_019f7115-c554-7cb0-a9ff-1544eed75272_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2027-2028</link:label>
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    <link:label id="lab_cik0001563922_TaxEquityInvestorsMember_label_en-US" xlink:label="lab_cik0001563922_TaxEquityInvestorsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Tax Equity Investors [Member]</link:label>
    <link:label id="lab_cik0001563922_TaxEquityInvestorsMember_documentation_en-US" xlink:label="lab_cik0001563922_TaxEquityInvestorsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tax Equity Investors</link:label>
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    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsNoncontrollingInterest_019f7115-c554-7805-8f53-07c181dbb8e1_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsNoncontrollingInterest" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Less: NCI transferred</link:label>
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    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsNoncontrollingInterest_documentation_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operations, Noncontrolling Interest</link:label>
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    <link:label id="lab_us-gaap_UnrealizedGainLossOnInvestmentsTableTextBlock_019f7115-c6fc-745e-bb47-deebbc9f4e64_terseLabel_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnInvestmentsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Change in Fair Value of Investments, Net</link:label>
    <link:label id="lab_us-gaap_UnrealizedGainLossOnInvestmentsTableTextBlock_label_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnInvestmentsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Unrealized Gain (Loss) on Investments [Table Text Block]</link:label>
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    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrentAbstract_019f7115-c6fc-71a8-9fa2-e8524436575d_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Current liabilities:</link:label>
    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrentAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]</link:label>
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    <link:label id="lab_us-gaap_LongTermDebt_019f7115-c5e8-792f-a523-aad26f0bfed9_totalLabel_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:label id="lab_us-gaap_LongTermDebt_label_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebt" xlink:to="lab_us-gaap_LongTermDebt" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_LegalEntityAxis_019f7115-c5e8-74f3-bba0-34d9826883ee_terseLabel_en-US" xlink:label="lab_dei_LegalEntityAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Legal Entity [Axis]</link:label>
    <link:label id="lab_dei_LegalEntityAxis_label_en-US" xlink:label="lab_dei_LegalEntityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Legal Entity [Axis]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_LegalEntityAxis" xlink:to="lab_dei_LegalEntityAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NonredeemableNoncontrollingInterest_019f7115-c6fc-76a8-ad69-5c170f04c926_terseLabel_en-US" xlink:label="lab_us-gaap_NonredeemableNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">NCI attributable to Tax Equity Investors</link:label>
    <link:label id="lab_us-gaap_NonredeemableNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_NonredeemableNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Nonredeemable Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonredeemableNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonredeemableNoncontrollingInterest"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NonredeemableNoncontrollingInterest" xlink:to="lab_us-gaap_NonredeemableNoncontrollingInterest" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_Assets_019f7115-c671-7ebf-b67e-8cbb5519ecab_totalLabel_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total assets</link:label>
    <link:label id="lab_us-gaap_Assets_019f7115-c671-7b63-8884-554184231611_terseLabel_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Assets</link:label>
    <link:label id="lab_us-gaap_Assets_label_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Assets</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Assets" xlink:to="lab_us-gaap_Assets" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAmortizationContraExpense_019f7115-c6fc-7160-91df-5cad91a5ca68_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAmortizationContraExpense" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Out-of-market contract amortization</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAmortizationContraExpense_label_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAmortizationContraExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Out-Of-Market Contracts, Intangible Liabilities, Amortization Contra-Expense</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAmortizationContraExpense_documentation_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAmortizationContraExpense" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Out-Of-Market Contracts, Intangible Liabilities, Amortization Contra-Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAmortizationContraExpense" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAmortizationContraExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAmortizationContraExpense" xlink:to="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAmortizationContraExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019f7115-c671-7f1c-9ab8-b70cb772ac86_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Vested, Weighted Average Fair Value (in dollars per share)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_019f7115-c555-7bc9-b4c7-2b9de02a53d7_terseLabel_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash and Cash Equivalents and Restricted Cash</link:label>
    <link:label id="lab_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_label_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:to="lab_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxPolicyTextBlock_019f7115-c6fc-7fd0-83cb-1877f378c749_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income Taxes and Tax Credit Transfers</link:label>
    <link:label id="lab_us-gaap_IncomeTaxPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_IncomeTaxPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxPolicyTextBlock" xlink:to="lab_us-gaap_IncomeTaxPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CiderSolarConstructionOwnerLLCFacilityMember_019f7115-c6fc-7bbd-a229-699ed4b1eb61_verboseLabel_en-US" xlink:label="lab_cik0001563922_CiderSolarConstructionOwnerLLCFacilityMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Cider Solar Manager LLC</link:label>
    <link:label id="lab_cik0001563922_CiderSolarConstructionOwnerLLCFacilityMember_label_en-US" xlink:label="lab_cik0001563922_CiderSolarConstructionOwnerLLCFacilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cider Solar Construction Owner LLC Facility [Member]</link:label>
    <link:label id="lab_cik0001563922_CiderSolarConstructionOwnerLLCFacilityMember_documentation_en-US" xlink:label="lab_cik0001563922_CiderSolarConstructionOwnerLLCFacilityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cider Solar Construction Owner LLC Facility</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CiderSolarConstructionOwnerLLCFacilityMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CiderSolarConstructionOwnerLLCFacilityMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CiderSolarConstructionOwnerLLCFacilityMember" xlink:to="lab_cik0001563922_CiderSolarConstructionOwnerLLCFacilityMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ZeroCustomerMember_019f7115-c554-7a12-8f3c-08d9c3d932bd_terseLabel_en-US" xlink:label="lab_cik0001563922_ZeroCustomerMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Zero Customer</link:label>
    <link:label id="lab_cik0001563922_ZeroCustomerMember_label_en-US" xlink:label="lab_cik0001563922_ZeroCustomerMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Zero Customer [Member]</link:label>
    <link:label id="lab_cik0001563922_ZeroCustomerMember_documentation_en-US" xlink:label="lab_cik0001563922_ZeroCustomerMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Zero Customer</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ZeroCustomerMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ZeroCustomerMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ZeroCustomerMember" xlink:to="lab_cik0001563922_ZeroCustomerMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetRetirementObligationCostsMember_019f7115-c6fc-7b65-9343-01ef0da04e29_terseLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationCostsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset retirement cost</link:label>
    <link:label id="lab_us-gaap_AssetRetirementObligationCostsMember_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationCostsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Retirement Obligation Costs [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationCostsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetRetirementObligationCostsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetRetirementObligationCostsMember" xlink:to="lab_us-gaap_AssetRetirementObligationCostsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019f7115-c6fc-76f6-9344-e6afac598626_verboseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Cash Flows from Operating Activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
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    <link:label id="lab_cik0001563922_NumberOfSubsidiaries_019f7115-c6fc-7bec-8b1d-dda63829bcdf_terseLabel_en-US" xlink:label="lab_cik0001563922_NumberOfSubsidiaries" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of subsidiaries</link:label>
    <link:label id="lab_cik0001563922_NumberOfSubsidiaries_label_en-US" xlink:label="lab_cik0001563922_NumberOfSubsidiaries" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number Of Subsidiaries</link:label>
    <link:label id="lab_cik0001563922_NumberOfSubsidiaries_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfSubsidiaries" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number Of Subsidiaries</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NumberOfSubsidiaries" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NumberOfSubsidiaries"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NumberOfSubsidiaries" xlink:to="lab_cik0001563922_NumberOfSubsidiaries" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MembersEquityAbstract_019f7115-c555-7f24-a613-a19675c9ce39_terseLabel_en-US" xlink:label="lab_us-gaap_MembersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Equity:</link:label>
    <link:label id="lab_us-gaap_MembersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_MembersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Members' Equity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MembersEquityAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MembersEquityAbstract" xlink:to="lab_us-gaap_MembersEquityAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019f7115-c671-786a-9235-d85ef89144c1_terseLabel_en-US" xlink:label="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Weighted-average amortization period (years) - favorable</link:label>
    <link:label id="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_label_en-US" xlink:label="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
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    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsCurrent_019f7115-c5e8-716b-90ec-6f9fe9b9b57e_terseLabel_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Less: origination costs, current</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsCurrent_label_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Origination Costs, Current</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsCurrent_documentation_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Origination Costs, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsCurrent" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FailedSaleLeasebackTransactionOriginationCostsCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsCurrent" xlink:to="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConcentrationRiskByTypeAxis_019f7115-c6fc-7c91-a2e2-58f03f93010d_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Concentration Risk Type [Axis]</link:label>
    <link:label id="lab_us-gaap_ConcentrationRiskByTypeAxis_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis" xlink:to="lab_us-gaap_ConcentrationRiskByTypeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation_019f7115-c554-70d0-aabb-0d1d1c1ca35d_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Decrease from deconsolidation</link:label>
    <link:label id="lab_us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation_label_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Decrease from Deconsolidation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation" xlink:to="lab_us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NumberOfFunds_019f7115-c554-7886-9ed7-0cff6eccf10d_terseLabel_en-US" xlink:label="lab_cik0001563922_NumberOfFunds" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of funds in renewable energy industry</link:label>
    <link:label id="lab_cik0001563922_NumberOfFunds_label_en-US" xlink:label="lab_cik0001563922_NumberOfFunds" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number Of Funds</link:label>
    <link:label id="lab_cik0001563922_NumberOfFunds_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfFunds" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number Of Funds</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NumberOfFunds" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NumberOfFunds"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NumberOfFunds" xlink:to="lab_cik0001563922_NumberOfFunds" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_VariableInterestEntityLineItems_019f7115-c5e8-79a0-a1d1-bf9d1fd76507_terseLabel_en-US" xlink:label="lab_us-gaap_VariableInterestEntityLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Interest Entity [Line Items]</link:label>
    <link:label id="lab_us-gaap_VariableInterestEntityLineItems_label_en-US" xlink:label="lab_us-gaap_VariableInterestEntityLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entity [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VariableInterestEntityLineItems" xlink:to="lab_us-gaap_VariableInterestEntityLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019f7115-c671-7693-bb9f-71c4860e0f31_terseLabel_en-US" xlink:label="lab_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impairment of long-lived assets, net and termination costs</link:label>
    <link:label id="lab_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_label_en-US" xlink:label="lab_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Impairment, Long-Lived Asset, Held-for-Use</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:to="lab_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConsolidationVariableInterestEntityPolicy_019f7115-c671-7388-be97-9e9440e31395_terseLabel_en-US" xlink:label="lab_us-gaap_ConsolidationVariableInterestEntityPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Interest Entities</link:label>
    <link:label id="lab_us-gaap_ConsolidationVariableInterestEntityPolicy_label_en-US" xlink:label="lab_us-gaap_ConsolidationVariableInterestEntityPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidation, Variable Interest Entity, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsolidationVariableInterestEntityPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConsolidationVariableInterestEntityPolicy"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConsolidationVariableInterestEntityPolicy" xlink:to="lab_us-gaap_ConsolidationVariableInterestEntityPolicy" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CapitalizedContractCostNet_019f7115-c5e8-723c-9d3f-f4cf87c75bca_terseLabel_en-US" xlink:label="lab_us-gaap_CapitalizedContractCostNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Capitalized costs to obtain a contract</link:label>
    <link:label id="lab_us-gaap_CapitalizedContractCostNet_label_en-US" xlink:label="lab_us-gaap_CapitalizedContractCostNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Capitalized Contract Cost, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNet" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedContractCostNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CapitalizedContractCostNet" xlink:to="lab_us-gaap_CapitalizedContractCostNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_019f7115-c6fc-7984-9157-7ff3d1a9969d_terseLabel_en-US" xlink:label="lab_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">ROU assets obtained in exchange for new and modified operating lease liabilities</link:label>
    <link:label id="lab_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_label_en-US" xlink:label="lab_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Right-of-Use Asset Obtained in Exchange for Operating Lease Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:to="lab_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LeaseCostAbstract_019f7115-c671-71cd-977b-74512e9dba34_terseLabel_en-US" xlink:label="lab_us-gaap_LeaseCostAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Lease cost</link:label>
    <link:label id="lab_us-gaap_LeaseCostAbstract_label_en-US" xlink:label="lab_us-gaap_LeaseCostAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease, Cost [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCostAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCostAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LeaseCostAbstract" xlink:to="lab_us-gaap_LeaseCostAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FairValueNetAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019f7115-c671-7e5c-8eec-fd5a42aa143b_terseLabel_en-US" xlink:label="lab_cik0001563922_FairValueNetAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:label id="lab_cik0001563922_FairValueNetAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_label_en-US" xlink:label="lab_cik0001563922_FairValueNetAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Net Assets (Liabilities) Measured On Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]</link:label>
    <link:label id="lab_cik0001563922_FairValueNetAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_documentation_en-US" xlink:label="lab_cik0001563922_FairValueNetAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fair Value, Net Assets (Liabilities) Measured On Recurring Basis, Unobservable Input Reconciliation, Calculation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FairValueNetAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FairValueNetAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FairValueNetAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:to="lab_cik0001563922_FairValueNetAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_HecateEnergyCiderSolarLLCMember_019f7115-c555-7da1-b899-8160ebd30c5b_terseLabel_en-US" xlink:label="lab_cik0001563922_HecateEnergyCiderSolarLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Hecate Energy Cider Solar LLC</link:label>
    <link:label id="lab_cik0001563922_HecateEnergyCiderSolarLLCMember_label_en-US" xlink:label="lab_cik0001563922_HecateEnergyCiderSolarLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Hecate Energy Cider Solar LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_HecateEnergyCiderSolarLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_HecateEnergyCiderSolarLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Hecate Energy Cider Solar LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_HecateEnergyCiderSolarLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_HecateEnergyCiderSolarLLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_HecateEnergyCiderSolarLLCMember" xlink:to="lab_cik0001563922_HecateEnergyCiderSolarLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueInputsLevel2Member_019f7115-c6fc-79c0-ba90-bea6474195ab_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Level 2</link:label>
    <link:label id="lab_us-gaap_FairValueInputsLevel2Member_label_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel2Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Inputs, Level 2 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel2Member" xlink:to="lab_us-gaap_FairValueInputsLevel2Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_019f7115-c671-70ee-9af6-92f0d07e257b_verboseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">State income taxes, net of federal benefit</link:label>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_label_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:to="lab_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DistributionMadeToLimitedLiabilityCompanyLLCMemberPreferredReturnAmount_019f7115-c554-7cbc-b5bf-557ed28bed08_terseLabel_en-US" xlink:label="lab_cik0001563922_DistributionMadeToLimitedLiabilityCompanyLLCMemberPreferredReturnAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Preferred return amount</link:label>
    <link:label id="lab_cik0001563922_DistributionMadeToLimitedLiabilityCompanyLLCMemberPreferredReturnAmount_label_en-US" xlink:label="lab_cik0001563922_DistributionMadeToLimitedLiabilityCompanyLLCMemberPreferredReturnAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distribution Made to Limited Liability Company (LLC) Member, Preferred Return Amount</link:label>
    <link:label id="lab_cik0001563922_DistributionMadeToLimitedLiabilityCompanyLLCMemberPreferredReturnAmount_documentation_en-US" xlink:label="lab_cik0001563922_DistributionMadeToLimitedLiabilityCompanyLLCMemberPreferredReturnAmount" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Distribution Made to Limited Liability Company (LLC) Member, Preferred Return Receivable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DistributionMadeToLimitedLiabilityCompanyLLCMemberPreferredReturnAmount" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DistributionMadeToLimitedLiabilityCompanyLLCMemberPreferredReturnAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DistributionMadeToLimitedLiabilityCompanyLLCMemberPreferredReturnAmount" xlink:to="lab_cik0001563922_DistributionMadeToLimitedLiabilityCompanyLLCMemberPreferredReturnAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ECAFincoILLCMember_019f7115-c6fc-7fdb-9e91-50e95ed5f25d_terseLabel_en-US" xlink:label="lab_cik0001563922_ECAFincoILLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">ECA Finco I, LLC</link:label>
    <link:label id="lab_cik0001563922_ECAFincoILLCMember_label_en-US" xlink:label="lab_cik0001563922_ECAFincoILLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">ECA Finco I, LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_ECAFincoILLCMember_documentation_en-US" xlink:label="lab_cik0001563922_ECAFincoILLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">ECA Finco I, LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ECAFincoILLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ECAFincoILLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ECAFincoILLCMember" xlink:to="lab_cik0001563922_ECAFincoILLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentPeriodIncreaseDecrease_019f7115-c554-75fe-9903-2489ac63f1ce_negatedLabel_en-US" xlink:label="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentPeriodIncreaseDecrease" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Decrease in accumulated amortization</link:label>
    <link:label id="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentPeriodIncreaseDecrease_label_en-US" xlink:label="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentPeriodIncreaseDecrease" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accumulated Depreciation, Depletion and Amortization, Property, Plant and Equipment, Period Increase (Decrease)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentPeriodIncreaseDecrease" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentPeriodIncreaseDecrease"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentPeriodIncreaseDecrease" xlink:to="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipmentPeriodIncreaseDecrease" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_TemporaryEquityNoncontrollingInterestChangeInRedemptionValue_019f7115-c5e8-75df-9242-54774048f4b9_terseLabel_en-US" xlink:label="lab_cik0001563922_TemporaryEquityNoncontrollingInterestChangeInRedemptionValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Redemption value adjustment for redeemable noncontrolling interest</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityNoncontrollingInterestChangeInRedemptionValue_label_en-US" xlink:label="lab_cik0001563922_TemporaryEquityNoncontrollingInterestChangeInRedemptionValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Noncontrolling Interest, Change In Redemption Value</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityNoncontrollingInterestChangeInRedemptionValue_documentation_en-US" xlink:label="lab_cik0001563922_TemporaryEquityNoncontrollingInterestChangeInRedemptionValue" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Temporary Equity, Noncontrolling Interest, Change In Redemption Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TemporaryEquityNoncontrollingInterestChangeInRedemptionValue" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TemporaryEquityNoncontrollingInterestChangeInRedemptionValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_TemporaryEquityNoncontrollingInterestChangeInRedemptionValue" xlink:to="lab_cik0001563922_TemporaryEquityNoncontrollingInterestChangeInRedemptionValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessAcquisitionAcquireeDomain_019f7115-c6fc-702a-a050-1816243df627_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Business Combination [Domain]</link:label>
    <link:label id="lab_us-gaap_BusinessAcquisitionAcquireeDomain_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Combination [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="lab_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentFeeAmount_019f7115-c554-700e-9abc-3579acec267b_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentFeeAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, fee amount</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentFeeAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentFeeAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Fee Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFeeAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFeeAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentFeeAmount" xlink:to="lab_us-gaap_DebtInstrumentFeeAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_019f7115-c5e8-783d-bfa0-4b62b377a8d3_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Leases</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RelatedPartyMember_019f7115-c671-7c15-b44a-a3b83804a72f_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Related Party</link:label>
    <link:label id="lab_us-gaap_RelatedPartyMember_label_en-US" xlink:label="lab_us-gaap_RelatedPartyMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyMember" xlink:to="lab_us-gaap_RelatedPartyMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DiscontinuedOperationsPolicyTextBlock_019f7115-c554-7602-b8eb-5e754bbe3532_terseLabel_en-US" xlink:label="lab_us-gaap_DiscontinuedOperationsPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Divestitures</link:label>
    <link:label id="lab_us-gaap_DiscontinuedOperationsPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_DiscontinuedOperationsPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Discontinued Operations, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DiscontinuedOperationsPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DiscontinuedOperationsPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DiscontinuedOperationsPolicyTextBlock" xlink:to="lab_us-gaap_DiscontinuedOperationsPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_019f7115-c6fc-7c0d-96e6-688282b8da33_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Consolidated Income Tax Benefit (Expense)</link:label>
    <link:label id="lab_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PlanNameAxis_019f7115-c6fb-7f0f-86ca-fc90784a0477_terseLabel_en-US" xlink:label="lab_us-gaap_PlanNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Plan Name [Axis]</link:label>
    <link:label id="lab_us-gaap_PlanNameAxis_label_en-US" xlink:label="lab_us-gaap_PlanNameAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Plan Name [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PlanNameAxis" xlink:to="lab_us-gaap_PlanNameAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_019f7115-c555-79d9-9ea2-ba05f6a4e140_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment, net</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ReimbursementOfConstructionCosts_019f7115-c5e8-76d5-8a27-0272aeb7ff44_terseLabel_en-US" xlink:label="lab_cik0001563922_ReimbursementOfConstructionCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Reimbursement of construction costs</link:label>
    <link:label id="lab_cik0001563922_ReimbursementOfConstructionCosts_label_en-US" xlink:label="lab_cik0001563922_ReimbursementOfConstructionCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reimbursement Of Construction Costs</link:label>
    <link:label id="lab_cik0001563922_ReimbursementOfConstructionCosts_documentation_en-US" xlink:label="lab_cik0001563922_ReimbursementOfConstructionCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Reimbursement Of Construction Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ReimbursementOfConstructionCosts" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ReimbursementOfConstructionCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ReimbursementOfConstructionCosts" xlink:to="lab_cik0001563922_ReimbursementOfConstructionCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearThree_019f7115-c554-7070-b53d-6d7a3de6b0e2_verboseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">2028-2029</link:label>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearThree_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Maturities, Repayments of Principal in Rolling Year Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearThree"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearThree" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearThree" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_019f7115-c555-7cfc-8148-c41687946cdd_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Intangibles</link:label>
    <link:label id="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Liabilities, Intangible Assets</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:to="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationUndiscountedExcessAmount_019f7115-c6fc-70e4-a352-2df8321a7843_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Less: Imputed interest</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationUndiscountedExcessAmount_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, Undiscounted Excess Amount</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationUndiscountedExcessAmount_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, Undiscounted Excess Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationUndiscountedExcessAmount" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionFinancingObligationUndiscountedExcessAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationUndiscountedExcessAmount" xlink:to="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationUndiscountedExcessAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NumberOfAssetsAcquired_019f7115-c6fc-7d68-ae81-737a77e7e136_terseLabel_en-US" xlink:label="lab_cik0001563922_NumberOfAssetsAcquired" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of assets acquired (in projects)</link:label>
    <link:label id="lab_cik0001563922_NumberOfAssetsAcquired_label_en-US" xlink:label="lab_cik0001563922_NumberOfAssetsAcquired" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number of Assets Acquired</link:label>
    <link:label id="lab_cik0001563922_NumberOfAssetsAcquired_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfAssetsAcquired" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number of Assets Acquired</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NumberOfAssetsAcquired" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NumberOfAssetsAcquired"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NumberOfAssetsAcquired" xlink:to="lab_cik0001563922_NumberOfAssetsAcquired" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019f7115-c5e8-7a5a-a641-37168e970810_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Changes in operating assets and liabilities:</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseFinancingObligation_019f7115-c76d-7876-91a3-9434d4724792_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseFinancingObligation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Financing interest</link:label>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseFinancingObligation_label_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseFinancingObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale And Leaseback Transaction, Interest Expense, Financing Obligation</link:label>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseFinancingObligation_documentation_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseFinancingObligation" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale And Leaseback Transaction, Interest Expense, Financing Obligation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleAndLeasebackTransactionInterestExpenseFinancingObligation" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleAndLeasebackTransactionInterestExpenseFinancingObligation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleAndLeasebackTransactionInterestExpenseFinancingObligation" xlink:to="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpenseFinancingObligation" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_019f7115-c6fc-762b-abdf-17633d8a7a68_verboseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Change in valuation allowance</link:label>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_label_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:to="lab_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrentAbstract_019f7115-c6fc-7ebe-bd00-4720f9ac374e_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Current assets:</link:label>
    <link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrentAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrentAbstract" xlink:to="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_019f7115-c6fc-7c32-b21e-2e3d1b0e3f01_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Property, plant, and equipment</link:label>
    <link:label id="lab_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Liabilities, Property, Plant and Equipment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:to="lab_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTaxRecognitionOfInitialFairValue_019f7115-c5e8-763e-93f9-2db47180d1aa_terseLabel_en-US" xlink:label="lab_cik0001563922_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTaxRecognitionOfInitialFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amortization of derivatives</link:label>
    <link:label id="lab_cik0001563922_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTaxRecognitionOfInitialFairValue_label_en-US" xlink:label="lab_cik0001563922_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTaxRecognitionOfInitialFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, After Tax, Recognition Of Initial Fair Value</link:label>
    <link:label id="lab_cik0001563922_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTaxRecognitionOfInitialFairValue_documentation_en-US" xlink:label="lab_cik0001563922_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTaxRecognitionOfInitialFairValue" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, After Tax, Recognition Of Initial Fair Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTaxRecognitionOfInitialFairValue" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTaxRecognitionOfInitialFairValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTaxRecognitionOfInitialFairValue" xlink:to="lab_cik0001563922_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTaxRecognitionOfInitialFairValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RetainedEarningsMember_019f7115-c6fc-7418-9af9-9eacaddf6533_terseLabel_en-US" xlink:label="lab_us-gaap_RetainedEarningsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accumulated deficit</link:label>
    <link:label id="lab_us-gaap_RetainedEarningsMember_label_en-US" xlink:label="lab_us-gaap_RetainedEarningsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Retained Earnings [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RetainedEarningsMember" xlink:to="lab_us-gaap_RetainedEarningsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxAuthorityAxis_019f7115-c671-7d82-84c0-0b8fd06fb300_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income Tax Authority [Axis]</link:label>
    <link:label id="lab_us-gaap_IncomeTaxAuthorityAxis_label_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax Jurisdiction [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis" xlink:to="lab_us-gaap_IncomeTaxAuthorityAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_label_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019f7115-c5e8-740e-90ca-46df26493bd8_periodStartLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Cash, cash equivalents and Restricted cash at beginning of period</link:label>
    <link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019f7115-c5e8-7ba3-95ab-0057aab2640b_periodEndLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Cash, cash equivalents and Restricted cash at end of period</link:label>
    <link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019f7115-c5e8-7298-a7d3-c30fceeaa9d7_totalLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total cash and cash equivalents and restricted cash</link:label>
    <link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_label_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeStatementAbstract_019f7115-c6fc-749d-bc0c-24ab9ccc8c40_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income Statement [Abstract]</link:label>
    <link:label id="lab_us-gaap_IncomeStatementAbstract_label_en-US" xlink:label="lab_us-gaap_IncomeStatementAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Statement [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementAbstract" xlink:to="lab_us-gaap_IncomeStatementAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeAssets_019f7115-c5e8-7ae6-8c8f-61890e471388_verboseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssets" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Derivative assets</link:label>
    <link:label id="lab_us-gaap_DerivativeAssets_019f7115-c5e8-73b6-a4b7-6c9cb2c36e89_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value - Assets</link:label>
    <link:label id="lab_us-gaap_DerivativeAssets_label_en-US" xlink:label="lab_us-gaap_DerivativeAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Asset</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssets"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeAssets" xlink:to="lab_us-gaap_DerivativeAssets" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MembersEquityAttributableToNoncontrollingInterest_019f7115-c5e8-76de-bbcd-1ca3ccc768c3_terseLabel_en-US" xlink:label="lab_us-gaap_MembersEquityAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Noncontrolling interests</link:label>
    <link:label id="lab_us-gaap_MembersEquityAttributableToNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_MembersEquityAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Members' Equity Attributable to Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquityAttributableToNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MembersEquityAttributableToNoncontrollingInterest"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MembersEquityAttributableToNoncontrollingInterest" xlink:to="lab_us-gaap_MembersEquityAttributableToNoncontrollingInterest" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GreenbackerAdministrationMember_019f7115-c6fc-79c1-b78f-ff992211d7ff_terseLabel_en-US" xlink:label="lab_cik0001563922_GreenbackerAdministrationMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Greenbacker Administration</link:label>
    <link:label id="lab_cik0001563922_GreenbackerAdministrationMember_label_en-US" xlink:label="lab_cik0001563922_GreenbackerAdministrationMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Greenbacker Administration [Member]</link:label>
    <link:label id="lab_cik0001563922_GreenbackerAdministrationMember_documentation_en-US" xlink:label="lab_cik0001563922_GreenbackerAdministrationMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Greenbacker Administration</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GreenbackerAdministrationMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GreenbackerAdministrationMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GreenbackerAdministrationMember" xlink:to="lab_cik0001563922_GreenbackerAdministrationMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InvestmentsFairValueDisclosure_019f7115-c6fc-7a6f-b63f-74aff4a43a79_verboseLabel_en-US" xlink:label="lab_us-gaap_InvestmentsFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Investments, at fair value</link:label>
    <link:label id="lab_us-gaap_InvestmentsFairValueDisclosure_019f7115-c6fc-7e52-8666-86eaa3dec3be_terseLabel_en-US" xlink:label="lab_us-gaap_InvestmentsFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investments at fair value</link:label>
    <link:label id="lab_us-gaap_InvestmentsFairValueDisclosure_label_en-US" xlink:label="lab_us-gaap_InvestmentsFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investments, Fair Value Disclosure</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsFairValueDisclosure" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentsFairValueDisclosure"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InvestmentsFairValueDisclosure" xlink:to="lab_us-gaap_InvestmentsFairValueDisclosure" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_InterestIncomeExpenseDebt_019f7115-c5e8-74c4-922c-064e037adc54_negatedTotalLabel_en-US" xlink:label="lab_cik0001563922_InterestIncomeExpenseDebt" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:label id="lab_cik0001563922_InterestIncomeExpenseDebt_label_en-US" xlink:label="lab_cik0001563922_InterestIncomeExpenseDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Income (Expense), Debt</link:label>
    <link:label id="lab_cik0001563922_InterestIncomeExpenseDebt_documentation_en-US" xlink:label="lab_cik0001563922_InterestIncomeExpenseDebt" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Interest Income (Expense), Debt</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_InterestIncomeExpenseDebt" xlink:href="cik0001563922-20260810.xsd#cik0001563922_InterestIncomeExpenseDebt"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_InterestIncomeExpenseDebt" xlink:to="lab_cik0001563922_InterestIncomeExpenseDebt" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill_019f7115-c5e8-790c-89fe-d2873908ffde_terseLabel_en-US" xlink:label="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Intangible assets, net</link:label>
    <link:label id="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill_label_en-US" xlink:label="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Intangible Assets, Net (Excluding Goodwill)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:to="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_ProductsAndServicesDomain_019f7115-c555-7040-8823-b79d40048b59_terseLabel_en-US" xlink:label="lab_srt_ProductsAndServicesDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Product and Service [Domain]</link:label>
    <link:label id="lab_srt_ProductsAndServicesDomain_label_en-US" xlink:label="lab_srt_ProductsAndServicesDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Product and Service [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ProductsAndServicesDomain" xlink:to="lab_srt_ProductsAndServicesDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CustomerConcentrationRiskMember_019f7115-c6fc-7ec5-8ef5-3c07cdb677d4_terseLabel_en-US" xlink:label="lab_us-gaap_CustomerConcentrationRiskMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Customer Concentration Risk</link:label>
    <link:label id="lab_us-gaap_CustomerConcentrationRiskMember_label_en-US" xlink:label="lab_us-gaap_CustomerConcentrationRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Customer Concentration Risk [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CustomerConcentrationRiskMember" xlink:to="lab_us-gaap_CustomerConcentrationRiskMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InterestExpenseDebtExcludingAmortization_019f7115-c671-777b-aa0e-23374f72c783_terseLabel_en-US" xlink:label="lab_us-gaap_InterestExpenseDebtExcludingAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Loan interest</link:label>
    <link:label id="lab_us-gaap_InterestExpenseDebtExcludingAmortization_label_en-US" xlink:label="lab_us-gaap_InterestExpenseDebtExcludingAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Expense, Debt, Excluding Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebtExcludingAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseDebtExcludingAmortization"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestExpenseDebtExcludingAmortization" xlink:to="lab_us-gaap_InterestExpenseDebtExcludingAmortization" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetRetirementObligationDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Retirement Obligation Disclosure [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetRetirementObligationDisclosureAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetRetirementObligationDisclosureAbstract" xlink:to="lab_us-gaap_AssetRetirementObligationDisclosureAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndDeferredInvestmentTaxCreditGainNoncurrent_019f7115-c6fc-74f1-bf80-3f653dec50d1_terseLabel_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndDeferredInvestmentTaxCreditGainNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Failed sale-leaseback financing and deferred ITC gain, net of current portion</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndDeferredInvestmentTaxCreditGainNoncurrent_019f7115-c6fc-7958-9d6b-d09552cfcc13_totalLabel_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndDeferredInvestmentTaxCreditGainNoncurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Failed sale-leaseback financing and deferred ITC gain, net of current portion</link:label>
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    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndDeferredInvestmentTaxCreditGainNoncurrent_documentation_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationAndDeferredInvestmentTaxCreditGainNoncurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Financing Obligation And Deferred Investment Tax Credit Gain, Noncurrent</link:label>
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    <link:label id="lab_us-gaap_ProfitLoss_019f7115-c555-73fd-86ea-b639b012d120_totalLabel_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net loss</link:label>
    <link:label id="lab_us-gaap_ProfitLoss_019f7115-c555-7c60-aed7-1070f74ee4e6_netLabel_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xml:lang="en-US">Net loss</link:label>
    <link:label id="lab_us-gaap_ProfitLoss_019f7115-c555-7d17-9f44-5836186197a6_terseLabel_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net loss</link:label>
    <link:label id="lab_us-gaap_ProfitLoss_label_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProfitLoss" xlink:to="lab_us-gaap_ProfitLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred_019f7115-c671-79bb-a9c5-29ec01a535e5_terseLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset retirement obligation incurred during current period</link:label>
    <link:label id="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Retirement Obligation, Liabilities Incurred</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetRetirementObligationLiabilitiesIncurred"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:to="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeNotionalAmount_019f7115-c554-74a4-afe4-10df6d77ce91_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeNotionalAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Initial notional amount</link:label>
    <link:label id="lab_us-gaap_DerivativeNotionalAmount_label_en-US" xlink:label="lab_us-gaap_DerivativeNotionalAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative, Notional Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeNotionalAmount" xlink:to="lab_us-gaap_DerivativeNotionalAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_019f7115-c6fc-768d-8af4-ce16c6f4ab28_terseLabel_en-US" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Organization, Consolidation and Presentation of Financial Statements [Abstract]</link:label>
    <link:label id="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_label_en-US" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Organization, Consolidation and Presentation of Financial Statements [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DirectorFeesMember_019f7115-c5e8-7ba7-85a6-87f68d240ec6_terseLabel_en-US" xlink:label="lab_cik0001563922_DirectorFeesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Director's fees</link:label>
    <link:label id="lab_cik0001563922_DirectorFeesMember_label_en-US" xlink:label="lab_cik0001563922_DirectorFeesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Director Fees [Member]</link:label>
    <link:label id="lab_cik0001563922_DirectorFeesMember_documentation_en-US" xlink:label="lab_cik0001563922_DirectorFeesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Director Fees</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DirectorFeesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DirectorFeesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DirectorFeesMember" xlink:to="lab_cik0001563922_DirectorFeesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_InvestmentTaxCreditPurchasePriceNetOfFeesAndExpenses_019f7115-c5e8-794c-adcd-57cd0b8fac4e_terseLabel_en-US" xlink:label="lab_cik0001563922_InvestmentTaxCreditPurchasePriceNetOfFeesAndExpenses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">ITC, purchase price</link:label>
    <link:label id="lab_cik0001563922_InvestmentTaxCreditPurchasePriceNetOfFeesAndExpenses_label_en-US" xlink:label="lab_cik0001563922_InvestmentTaxCreditPurchasePriceNetOfFeesAndExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investment Tax Credit, Purchase Price, Net Of Fees And Expenses</link:label>
    <link:label id="lab_cik0001563922_InvestmentTaxCreditPurchasePriceNetOfFeesAndExpenses_documentation_en-US" xlink:label="lab_cik0001563922_InvestmentTaxCreditPurchasePriceNetOfFeesAndExpenses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Investment Tax Credit, Purchase Price, Net Of Fees And Expenses</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_InvestmentTaxCreditPurchasePriceNetOfFeesAndExpenses" xlink:href="cik0001563922-20260810.xsd#cik0001563922_InvestmentTaxCreditPurchasePriceNetOfFeesAndExpenses"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_InvestmentTaxCreditPurchasePriceNetOfFeesAndExpenses" xlink:to="lab_cik0001563922_InvestmentTaxCreditPurchasePriceNetOfFeesAndExpenses" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditAfterRollingYearFive_019f7115-c671-778b-9bdb-9f0224af3128_terseLabel_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Thereafter</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditAfterRollingYearFive_label_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, After Rolling Year Five</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditAfterRollingYearFive_documentation_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, After Rolling Year Five</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditAfterRollingYearFive" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CommitmentToSellRenewableEnergyCreditAfterRollingYearFive"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditAfterRollingYearFive" xlink:to="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditAfterRollingYearFive" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ChannelPartnerRelationshipsMember_019f7115-c554-79b0-88c5-f10df6c301d4_terseLabel_en-US" xlink:label="lab_cik0001563922_ChannelPartnerRelationshipsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Channel partner relationships</link:label>
    <link:label id="lab_cik0001563922_ChannelPartnerRelationshipsMember_label_en-US" xlink:label="lab_cik0001563922_ChannelPartnerRelationshipsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Channel Partner Relationships [Member]</link:label>
    <link:label id="lab_cik0001563922_ChannelPartnerRelationshipsMember_documentation_en-US" xlink:label="lab_cik0001563922_ChannelPartnerRelationshipsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Channel Partner Relationships</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ChannelPartnerRelationshipsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ChannelPartnerRelationshipsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ChannelPartnerRelationshipsMember" xlink:to="lab_cik0001563922_ChannelPartnerRelationshipsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageIncreaseOnEachAnniversaryOfCommonSharesIssuedAndOutstandingForIssuanceToEmployeesAndNonEmployeeDirectors_019f7115-c6fc-711f-bf0e-34dce98f7c4f_terseLabel_en-US" xlink:label="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageIncreaseOnEachAnniversaryOfCommonSharesIssuedAndOutstandingForIssuanceToEmployeesAndNonEmployeeDirectors" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Percentage increase on each anniversary to authorized percentage of common shares that are issued and outstanding for issuance to employee and non-employee directors</link:label>
    <link:label id="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageIncreaseOnEachAnniversaryOfCommonSharesIssuedAndOutstandingForIssuanceToEmployeesAndNonEmployeeDirectors_label_en-US" xlink:label="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageIncreaseOnEachAnniversaryOfCommonSharesIssuedAndOutstandingForIssuanceToEmployeesAndNonEmployeeDirectors" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Percentage Increase On Each Anniversary Of Common Shares Issued And Outstanding For Issuance To Employees And Non-Employee Directors</link:label>
    <link:label id="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageIncreaseOnEachAnniversaryOfCommonSharesIssuedAndOutstandingForIssuanceToEmployeesAndNonEmployeeDirectors_documentation_en-US" xlink:label="lab_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageIncreaseOnEachAnniversaryOfCommonSharesIssuedAndOutstandingForIssuanceToEmployeesAndNonEmployeeDirectors" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Percentage Increase On Each Anniversary Of Common Shares Issued And Outstanding For Issuance To Employees And Non-Employee Directors</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageIncreaseOnEachAnniversaryOfCommonSharesIssuedAndOutstandingForIssuanceToEmployeesAndNonEmployeeDirectors" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageIncreaseOnEachAnniversaryOfCommonSharesIssuedAndOutstandingForIssuanceToEmployeesAndNonEmployeeDirectors"/>
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    <link:label id="lab_cik0001563922_ContractAmortizationExpense_019f7115-c555-7ce1-97d9-d9e1e7d55650_verboseLabel_en-US" xlink:label="lab_cik0001563922_ContractAmortizationExpense" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Add back: Contract amortization, net</link:label>
    <link:label id="lab_cik0001563922_ContractAmortizationExpense_019f7115-c555-7829-9993-daecb0d57049_terseLabel_en-US" xlink:label="lab_cik0001563922_ContractAmortizationExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contract amortization on PPA and REC contracts, intangible assets and out-of-market contracts, net</link:label>
    <link:label id="lab_cik0001563922_ContractAmortizationExpense_label_en-US" xlink:label="lab_cik0001563922_ContractAmortizationExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract Amortization Expense</link:label>
    <link:label id="lab_cik0001563922_ContractAmortizationExpense_documentation_en-US" xlink:label="lab_cik0001563922_ContractAmortizationExpense" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Contract Amortization Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ContractAmortizationExpense" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ContractAmortizationExpense"/>
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    <link:label id="lab_cik0001563922_UnderConstructionCostsOfSolarProject_019f7115-c554-7bf1-8bc0-7be1348ec173_terseLabel_en-US" xlink:label="lab_cik0001563922_UnderConstructionCostsOfSolarProject" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Under construction costs of solar project</link:label>
    <link:label id="lab_cik0001563922_UnderConstructionCostsOfSolarProject_label_en-US" xlink:label="lab_cik0001563922_UnderConstructionCostsOfSolarProject" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Under Construction Costs Of Solar Project</link:label>
    <link:label id="lab_cik0001563922_UnderConstructionCostsOfSolarProject_documentation_en-US" xlink:label="lab_cik0001563922_UnderConstructionCostsOfSolarProject" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Under Construction Costs Of Solar Project</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_UnderConstructionCostsOfSolarProject" xlink:href="cik0001563922-20260810.xsd#cik0001563922_UnderConstructionCostsOfSolarProject"/>
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    <link:label id="lab_us-gaap_DeferredTaxLiabilities_019f7115-c6fc-7b0d-ace6-888719b45504_negatedTotalLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilities" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xml:lang="en-US">Deferred tax liabilities, net</link:label>
    <link:label id="lab_us-gaap_DeferredTaxLiabilities_019f7115-c6fc-7eb5-9ae4-f8b7ebffab1f_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net deferred tax liability</link:label>
    <link:label id="lab_us-gaap_DeferredTaxLiabilities_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Liabilities, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxLiabilities" xlink:to="lab_us-gaap_DeferredTaxLiabilities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019f7115-c5e8-7d21-b892-d08de8ffacd7_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash Flows from Investing Activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
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    <link:label id="lab_us-gaap_GeneralAndAdministrativeExpense_019f7115-c5e8-77b1-8160-8b72b10e0d52_terseLabel_en-US" xlink:label="lab_us-gaap_GeneralAndAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">General and administrative</link:label>
    <link:label id="lab_us-gaap_GeneralAndAdministrativeExpense_label_en-US" xlink:label="lab_us-gaap_GeneralAndAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">General and Administrative Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GeneralAndAdministrativeExpense" xlink:to="lab_us-gaap_GeneralAndAdministrativeExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationOriginationCosts_019f7115-c5e8-729f-b122-231863688304_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationOriginationCosts" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Less: Origination costs</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationOriginationCosts_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationOriginationCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, Origination Costs</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationOriginationCosts_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationOriginationCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, Origination Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationOriginationCosts" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionFinancingObligationOriginationCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationOriginationCosts" xlink:to="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationOriginationCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_019f7115-c554-78a3-8f62-80b82c36ab30_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Disposal Group, Disposed of by Sale, Not Discontinued Operations</link:label>
    <link:label id="lab_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_label_en-US" xlink:label="lab_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:to="lab_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RelatedPartyTransactionsAbstract_019f7115-c5e8-79df-ae46-7b2d98bb55e5_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Related Party Transactions [Abstract]</link:label>
    <link:label id="lab_us-gaap_RelatedPartyTransactionsAbstract_label_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party Transactions [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyTransactionsAbstract" xlink:to="lab_us-gaap_RelatedPartyTransactionsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LeaseCost_019f7115-c671-71e6-abee-9fd8e12242d2_totalLabel_en-US" xlink:label="lab_us-gaap_LeaseCost" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total lease cost</link:label>
    <link:label id="lab_us-gaap_LeaseCost_label_en-US" xlink:label="lab_us-gaap_LeaseCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease, Cost</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCost" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCost"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LeaseCost" xlink:to="lab_us-gaap_LeaseCost" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LeaseCostTableTextBlock_019f7115-c555-78f6-9bf5-c86870ff4c6f_terseLabel_en-US" xlink:label="lab_us-gaap_LeaseCostTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Components of Lease Expense and Supplemental Cash Flow Information</link:label>
    <link:label id="lab_us-gaap_LeaseCostTableTextBlock_label_en-US" xlink:label="lab_us-gaap_LeaseCostTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease, Cost [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCostTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCostTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LeaseCostTableTextBlock" xlink:to="lab_us-gaap_LeaseCostTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_InterestRateSwapEffectiveMember_019f7115-c555-7791-ac09-fddd5760cf3d_terseLabel_en-US" xlink:label="lab_cik0001563922_InterestRateSwapEffectiveMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest Rate Swap, Effective</link:label>
    <link:label id="lab_cik0001563922_InterestRateSwapEffectiveMember_label_en-US" xlink:label="lab_cik0001563922_InterestRateSwapEffectiveMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Rate Swap, Effective [Member]</link:label>
    <link:label id="lab_cik0001563922_InterestRateSwapEffectiveMember_documentation_en-US" xlink:label="lab_cik0001563922_InterestRateSwapEffectiveMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Interest Rate Swap, Effective</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_InterestRateSwapEffectiveMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_InterestRateSwapEffectiveMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_InterestRateSwapEffectiveMember" xlink:to="lab_cik0001563922_InterestRateSwapEffectiveMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_019f7115-c671-72ba-a047-0223c05628c8_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Federal</link:label>
    <link:label id="lab_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Federal Income Tax Expense (Benefit)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:to="lab_us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConcentrationRiskTable_019f7115-c6fc-74b4-9a32-7df5ae61e9bf_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Concentration Risk [Table]</link:label>
    <link:label id="lab_us-gaap_ConcentrationRiskTable_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskTable" xlink:to="lab_us-gaap_ConcentrationRiskTable" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AdvisorMember_019f7115-c5e8-7e9b-85f5-5b466e88b0ee_terseLabel_en-US" xlink:label="lab_cik0001563922_AdvisorMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Greenbacker Capital Management LLC</link:label>
    <link:label id="lab_cik0001563922_AdvisorMember_label_en-US" xlink:label="lab_cik0001563922_AdvisorMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Greenbacker Capital Management LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_AdvisorMember_documentation_en-US" xlink:label="lab_cik0001563922_AdvisorMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">It refers to the related party.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AdvisorMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AdvisorMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_AdvisorMember" xlink:to="lab_cik0001563922_AdvisorMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DogwoodAndCeladonMember_019f7115-c554-7e46-b0f0-eee66e9edc77_terseLabel_en-US" xlink:label="lab_cik0001563922_DogwoodAndCeladonMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Dogwood and Celadon</link:label>
    <link:label id="lab_cik0001563922_DogwoodAndCeladonMember_label_en-US" xlink:label="lab_cik0001563922_DogwoodAndCeladonMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dogwood and Celadon [Member]</link:label>
    <link:label id="lab_cik0001563922_DogwoodAndCeladonMember_documentation_en-US" xlink:label="lab_cik0001563922_DogwoodAndCeladonMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Dogwood and Celadon</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DogwoodAndCeladonMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DogwoodAndCeladonMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DogwoodAndCeladonMember" xlink:to="lab_cik0001563922_DogwoodAndCeladonMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EnergyCommoditiesAndServiceMember_019f7115-c5e8-7454-a3ac-5a7e9caae103_terseLabel_en-US" xlink:label="lab_us-gaap_EnergyCommoditiesAndServiceMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Energy revenue</link:label>
    <link:label id="lab_us-gaap_EnergyCommoditiesAndServiceMember_019f7115-c5e8-78ea-91e7-edfded6ea3e8_verboseLabel_en-US" xlink:label="lab_us-gaap_EnergyCommoditiesAndServiceMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Energy revenue</link:label>
    <link:label id="lab_us-gaap_EnergyCommoditiesAndServiceMember_label_en-US" xlink:label="lab_us-gaap_EnergyCommoditiesAndServiceMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Energy Commodities and Service [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnergyCommoditiesAndServiceMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EnergyCommoditiesAndServiceMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EnergyCommoditiesAndServiceMember" xlink:to="lab_us-gaap_EnergyCommoditiesAndServiceMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SupplementalCashFlowInformationAbstract_019f7115-c555-7328-adba-7118d449a4fd_netLabel_en-US" xlink:label="lab_us-gaap_SupplementalCashFlowInformationAbstract" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xml:lang="en-US">Cash paid for</link:label>
    <link:label id="lab_us-gaap_SupplementalCashFlowInformationAbstract_label_en-US" xlink:label="lab_us-gaap_SupplementalCashFlowInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Supplemental Cash Flow Information [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SupplementalCashFlowInformationAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="lab_us-gaap_SupplementalCashFlowInformationAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ContingentConsiderationClassifiedAsEquityNotAchievedParticipatingStatusFairValueDisclosure_019f7115-c555-782f-827e-a535a16b0c6f_terseLabel_en-US" xlink:label="lab_cik0001563922_ContingentConsiderationClassifiedAsEquityNotAchievedParticipatingStatusFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair value of shares not yet achieved status of participating</link:label>
    <link:label id="lab_cik0001563922_ContingentConsiderationClassifiedAsEquityNotAchievedParticipatingStatusFairValueDisclosure_label_en-US" xlink:label="lab_cik0001563922_ContingentConsiderationClassifiedAsEquityNotAchievedParticipatingStatusFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contingent Consideration Classified As Equity, Not Achieved Participating Status, Fair Value Disclosure</link:label>
    <link:label id="lab_cik0001563922_ContingentConsiderationClassifiedAsEquityNotAchievedParticipatingStatusFairValueDisclosure_documentation_en-US" xlink:label="lab_cik0001563922_ContingentConsiderationClassifiedAsEquityNotAchievedParticipatingStatusFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Contingent Consideration Classified As Equity, Not Achieved Participating Status, Fair Value Disclosure</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ContingentConsiderationClassifiedAsEquityNotAchievedParticipatingStatusFairValueDisclosure" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ContingentConsiderationClassifiedAsEquityNotAchievedParticipatingStatusFairValueDisclosure"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ContingentConsiderationClassifiedAsEquityNotAchievedParticipatingStatusFairValueDisclosure" xlink:to="lab_cik0001563922_ContingentConsiderationClassifiedAsEquityNotAchievedParticipatingStatusFairValueDisclosure" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidAfterRollingYearFive_019f7115-c5e8-7f5e-aa92-d4a4f97321ed_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Thereafter</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidAfterRollingYearFive_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, After Rolling Year Five</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidAfterRollingYearFive_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidAfterRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, After Rolling Year Five</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidAfterRollingYearFive" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidAfterRollingYearFive"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidAfterRollingYearFive" xlink:to="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidAfterRollingYearFive" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ScheduleOfNoncontrollingInterestTableTextBlock_019f7115-c555-73df-bf07-f5c8aea2082f_terseLabel_en-US" xlink:label="lab_cik0001563922_ScheduleOfNoncontrollingInterestTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Net Income (Loss) to Noncontrolling Interest for Tax Equity Investors</link:label>
    <link:label id="lab_cik0001563922_ScheduleOfNoncontrollingInterestTableTextBlock_label_en-US" xlink:label="lab_cik0001563922_ScheduleOfNoncontrollingInterestTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule Of Noncontrolling Interest [Table Text Block]</link:label>
    <link:label id="lab_cik0001563922_ScheduleOfNoncontrollingInterestTableTextBlock_documentation_en-US" xlink:label="lab_cik0001563922_ScheduleOfNoncontrollingInterestTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Schedule Of Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ScheduleOfNoncontrollingInterestTableTextBlock" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ScheduleOfNoncontrollingInterestTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ScheduleOfNoncontrollingInterestTableTextBlock" xlink:to="lab_cik0001563922_ScheduleOfNoncontrollingInterestTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock_019f7115-c671-77c4-845b-4297e8cc2f03_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Measurements</link:label>
    <link:label id="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Measurement, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:to="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_Dividends_019f7115-c671-7117-8303-0671ed93e10c_terseLabel_en-US" xlink:label="lab_us-gaap_Dividends" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:label id="lab_us-gaap_Dividends_label_en-US" xlink:label="lab_us-gaap_Dividends" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dividends</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Dividends" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Dividends"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Dividends" xlink:to="lab_us-gaap_Dividends" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredTaxAssetDomain_019f7115-c554-7268-bc89-b1e1e422c941_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred Tax Asset [Domain]</link:label>
    <link:label id="lab_us-gaap_DeferredTaxAssetDomain_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Asset [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxAssetDomain" xlink:to="lab_us-gaap_DeferredTaxAssetDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RelatedPartyDomain_019f7115-c5e8-703c-a22b-f991b1018fc8_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Related Party [Domain]</link:label>
    <link:label id="lab_us-gaap_RelatedPartyDomain_label_en-US" xlink:label="lab_us-gaap_RelatedPartyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related and Nonrelated Parties [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyDomain" xlink:to="lab_us-gaap_RelatedPartyDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_019f7115-c671-7962-910b-6237b76c7f09_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amount</link:label>
    <link:label id="lab_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_label_en-US" xlink:label="lab_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract" xlink:to="lab_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_VariableRateTimeframeDomain_019f7115-c5e8-716f-bbde-275522b75672_terseLabel_en-US" xlink:label="lab_cik0001563922_VariableRateTimeframeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Rate, Timeframe [Domain]</link:label>
    <link:label id="lab_cik0001563922_VariableRateTimeframeDomain_label_en-US" xlink:label="lab_cik0001563922_VariableRateTimeframeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Rate, Timeframe [Domain]</link:label>
    <link:label id="lab_cik0001563922_VariableRateTimeframeDomain_documentation_en-US" xlink:label="lab_cik0001563922_VariableRateTimeframeDomain" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Variable Rate, Timeframe [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_VariableRateTimeframeDomain" xlink:href="cik0001563922-20260810.xsd#cik0001563922_VariableRateTimeframeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_VariableRateTimeframeDomain" xlink:to="lab_cik0001563922_VariableRateTimeframeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InterestCostsCapitalizedAdjustment_019f7115-c5e8-7300-8d28-ed016c5630e9_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_InterestCostsCapitalizedAdjustment" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Interest capitalized</link:label>
    <link:label id="lab_us-gaap_InterestCostsCapitalizedAdjustment_label_en-US" xlink:label="lab_us-gaap_InterestCostsCapitalizedAdjustment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Costs Capitalized Adjustment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestCostsCapitalizedAdjustment" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestCostsCapitalizedAdjustment"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestCostsCapitalizedAdjustment" xlink:to="lab_us-gaap_InterestCostsCapitalizedAdjustment" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeInstrumentRiskAxis_019f7115-c76d-7327-911b-5d8120628451_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative Instrument [Axis]</link:label>
    <link:label id="lab_us-gaap_DerivativeInstrumentRiskAxis_label_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Instrument [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis" xlink:to="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_BaseManagementFeePayableAnnualRateAmountReduced_019f7115-c555-7eee-8a37-d5a18a8834c2_terseLabel_en-US" xlink:label="lab_cik0001563922_BaseManagementFeePayableAnnualRateAmountReduced" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Base management fee payable, annual rate, amount reduced</link:label>
    <link:label id="lab_cik0001563922_BaseManagementFeePayableAnnualRateAmountReduced_label_en-US" xlink:label="lab_cik0001563922_BaseManagementFeePayableAnnualRateAmountReduced" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Base Management Fee Payable, Annual Rate, Amount Reduced</link:label>
    <link:label id="lab_cik0001563922_BaseManagementFeePayableAnnualRateAmountReduced_documentation_en-US" xlink:label="lab_cik0001563922_BaseManagementFeePayableAnnualRateAmountReduced" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Base Management Fee Payable, Annual Rate, Amount Reduced</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_BaseManagementFeePayableAnnualRateAmountReduced" xlink:href="cik0001563922-20260810.xsd#cik0001563922_BaseManagementFeePayableAnnualRateAmountReduced"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_BaseManagementFeePayableAnnualRateAmountReduced" xlink:to="lab_cik0001563922_BaseManagementFeePayableAnnualRateAmountReduced" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_VestingAxis_019f7115-c5e8-72f2-bd89-d4556f5c670a_terseLabel_en-US" xlink:label="lab_us-gaap_VestingAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Vesting [Axis]</link:label>
    <link:label id="lab_us-gaap_VestingAxis_label_en-US" xlink:label="lab_us-gaap_VestingAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Vesting [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VestingAxis" xlink:to="lab_us-gaap_VestingAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LesseeFinanceLeasesTextBlock_019f7115-c5e8-7a0a-8ab8-5fa2b2edb453_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeFinanceLeasesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Leases</link:label>
    <link:label id="lab_us-gaap_LesseeFinanceLeasesTextBlock_label_en-US" xlink:label="lab_us-gaap_LesseeFinanceLeasesTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Finance Leases [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeFinanceLeasesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeFinanceLeasesTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeFinanceLeasesTextBlock" xlink:to="lab_us-gaap_LesseeFinanceLeasesTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherAssetsCurrent_019f7115-c671-7a67-bcfc-ea87fba0af37_verboseLabel_en-US" xlink:label="lab_us-gaap_OtherAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Other current assets</link:label>
    <link:label id="lab_us-gaap_OtherAssetsCurrent_label_en-US" xlink:label="lab_us-gaap_OtherAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Assets, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherAssetsCurrent" xlink:to="lab_us-gaap_OtherAssetsCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_LongLivedAssetsImpairmentLoss_019f7115-c671-73fd-a449-9c0491bb81cc_terseLabel_en-US" xlink:label="lab_cik0001563922_LongLivedAssetsImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-lived assets, impairment loss</link:label>
    <link:label id="lab_cik0001563922_LongLivedAssetsImpairmentLoss_label_en-US" xlink:label="lab_cik0001563922_LongLivedAssetsImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Lived Assets, Impairment Loss</link:label>
    <link:label id="lab_cik0001563922_LongLivedAssetsImpairmentLoss_documentation_en-US" xlink:label="lab_cik0001563922_LongLivedAssetsImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Long-Lived Assets, Impairment Loss</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_LongLivedAssetsImpairmentLoss" xlink:href="cik0001563922-20260810.xsd#cik0001563922_LongLivedAssetsImpairmentLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_LongLivedAssetsImpairmentLoss" xlink:to="lab_cik0001563922_LongLivedAssetsImpairmentLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityDomain_019f7115-c555-7e25-93ea-874157b09271_terseLabel_en-US" xlink:label="lab_dei_EntityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity [Domain]</link:label>
    <link:label id="lab_dei_EntityDomain_label_en-US" xlink:label="lab_dei_EntityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityDomain" xlink:to="lab_dei_EntityDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities_019f7115-c6fc-7ccf-876b-93779cab4f63_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash used in investing activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash Provided by (Used in) Investing Activity, Including Discontinued Operation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f7115-c5e8-73b0-a1f8-d2ab5a82a8c8_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Remaining performance obligations, period</link:label>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
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    <link:label id="lab_cik0001563922_GoodwillIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilitiesDisclosureTextBlock_019f7115-c555-7e75-8adc-5a0b2aa8c504_terseLabel_en-US" xlink:label="lab_cik0001563922_GoodwillIntangibleAssetsAndOutOfMarketContractsIntangibleLiabilitiesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Intangible Assets and Out-of-market Contracts</link:label>
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    <link:label id="lab_us-gaap_DerivativeAssetsNoncurrent_019f7115-c671-7b25-8987-575127f5f662_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative assets</link:label>
    <link:label id="lab_us-gaap_DerivativeAssetsNoncurrent_label_en-US" xlink:label="lab_us-gaap_DerivativeAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Asset, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetsNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeAssetsNoncurrent" xlink:to="lab_us-gaap_DerivativeAssetsNoncurrent" xlink:type="arc" order="1"/>
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    <link:label id="lab_us-gaap_LineOfCreditFacilityAxis_019f7115-c554-7c33-8981-88c0837fff74_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Lender Name [Axis]</link:label>
    <link:label id="lab_us-gaap_LineOfCreditFacilityAxis_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lender Name [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis" xlink:to="lab_us-gaap_LineOfCreditFacilityAxis" xlink:type="arc" order="1"/>
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    <link:label id="lab_us-gaap_OperatingLeaseRightOfUseAsset_019f7115-c671-766f-909a-36b5d154aa09_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseRightOfUseAsset" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating lease assets</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseRightOfUseAsset_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseRightOfUseAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Right-of-Use Asset</link:label>
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    <link:label id="lab_us-gaap_NotesAndLoansReceivableNetCurrent_label_en-US" xlink:label="lab_us-gaap_NotesAndLoansReceivableNetCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Financing Receivable, after Allowance for Credit Loss, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesAndLoansReceivableNetCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesAndLoansReceivableNetCurrent"/>
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    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019f7115-c671-7ac3-81bb-abacfdb20c12_totalLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Provision (benefit) for income taxes</link:label>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
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    <link:label id="lab_us-gaap_OperatingLeaseCost_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Cost</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseCost" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseCost"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseCost" xlink:to="lab_us-gaap_OperatingLeaseCost" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PlanNameDomain_019f7115-c5e8-7bf6-8eab-d16f941c0713_terseLabel_en-US" xlink:label="lab_us-gaap_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Plan Name [Domain]</link:label>
    <link:label id="lab_us-gaap_PlanNameDomain_label_en-US" xlink:label="lab_us-gaap_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Plan Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="lab_us-gaap_PlanNameDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019f7115-c6fc-70ed-9dc6-f8ddff6d790a_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Weighted-average period for recognition of unrecognized compensation cost (in years)</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
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    <link:label id="lab_us-gaap_DeferredTaxAssetsValuationAllowance_019f7115-c671-76a3-a57e-986767ba9ad8_negatedLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Less: Valuation allowance</link:label>
    <link:label id="lab_us-gaap_DeferredTaxAssetsValuationAllowance_019f7115-c671-72aa-84cd-4b221db0015b_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Valuation allowance</link:label>
    <link:label id="lab_us-gaap_DeferredTaxAssetsValuationAllowance_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Assets, Valuation Allowance</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsValuationAllowance"/>
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    <link:label id="lab_us-gaap_EquityAbstract_019f7115-c5e8-71b6-9e94-19aee726b0a3_terseLabel_en-US" xlink:label="lab_us-gaap_EquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Equity [Abstract]</link:label>
    <link:label id="lab_us-gaap_EquityAbstract_label_en-US" xlink:label="lab_us-gaap_EquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityAbstract"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet"/>
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    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsPPARenewableEnergyCreditRECContractAndOutOfMarketContractsIntangibleLiabilitiesMember_019f7115-c671-7770-bd2a-8fd702d40ac6_terseLabel_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsPPARenewableEnergyCreditRECContractAndOutOfMarketContractsIntangibleLiabilitiesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Power Purchase Agreements ("PPA"), Renewable Energy Credit ("REC") Contract and Out-of-market Contracts, Intangible Liabilities</link:label>
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    <link:label id="lab_us-gaap_PurchaseObligation_019f7115-c5e8-753c-b290-98ecaa333ec0_terseLabel_en-US" xlink:label="lab_us-gaap_PurchaseObligation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total purchase price</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PurchaseObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PurchaseObligation"/>
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    <link:label id="lab_us-gaap_TradeAndOtherAccountsReceivablePolicy_019f7115-c671-7103-9f26-dd65ad2301d4_terseLabel_en-US" xlink:label="lab_us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounts Receivable and Allowance for Credit Losses</link:label>
    <link:label id="lab_us-gaap_TradeAndOtherAccountsReceivablePolicy_label_en-US" xlink:label="lab_us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts Receivable [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeAndOtherAccountsReceivablePolicy"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:to="lab_us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseLiability_019f7115-c555-736a-a87c-f4197bdc2e6c_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Present value of lease liabilities</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiability_019f7115-c555-71f8-a598-916039c8228d_negatedTotalLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiability" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xml:lang="en-US">Total finance lease liabilities</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiability_019f7115-c555-7ffd-927c-d94ca8fde65a_verboseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Present value of lease liabilities</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiability_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiability"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiability" xlink:to="lab_us-gaap_FinanceLeaseLiability" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementBusinessSegmentsAxis_019f7115-c6fc-7360-b59e-37b112633d9e_terseLabel_en-US" xlink:label="lab_us-gaap_StatementBusinessSegmentsAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Segments [Axis]</link:label>
    <link:label id="lab_us-gaap_StatementBusinessSegmentsAxis_label_en-US" xlink:label="lab_us-gaap_StatementBusinessSegmentsAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segments [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis" xlink:to="lab_us-gaap_StatementBusinessSegmentsAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f7115-c5e8-7ee5-975b-7282962363f2_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value by Liability Class [Domain]</link:label>
    <link:label id="lab_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_label_en-US" xlink:label="lab_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value by Liability Class [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="lab_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SpecialUnitHolderMember_019f7115-c6fc-7712-926f-b7eb84495119_terseLabel_en-US" xlink:label="lab_cik0001563922_SpecialUnitHolderMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Special Unitholder</link:label>
    <link:label id="lab_cik0001563922_SpecialUnitHolderMember_label_en-US" xlink:label="lab_cik0001563922_SpecialUnitHolderMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Special Unitholder [Member]</link:label>
    <link:label id="lab_cik0001563922_SpecialUnitHolderMember_documentation_en-US" xlink:label="lab_cik0001563922_SpecialUnitHolderMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Special Unitholder</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SpecialUnitHolderMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SpecialUnitHolderMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SpecialUnitHolderMember" xlink:to="lab_cik0001563922_SpecialUnitHolderMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_019f7115-c6fc-7f38-8698-7b78c223a2d0_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Other investing activities</link:label>
    <link:label id="lab_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_label_en-US" xlink:label="lab_us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payment for (Proceeds from) Other Investing Activity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:to="lab_us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherOperatingActivitiesCashFlowStatement_019f7115-c5e8-7d60-bf12-092bb05668fa_terseLabel_en-US" xlink:label="lab_us-gaap_OtherOperatingActivitiesCashFlowStatement" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:label id="lab_us-gaap_OtherOperatingActivitiesCashFlowStatement_label_en-US" xlink:label="lab_us-gaap_OtherOperatingActivitiesCashFlowStatement" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Other Item</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherOperatingActivitiesCashFlowStatement"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement" xlink:to="lab_us-gaap_OtherOperatingActivitiesCashFlowStatement" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_019f7115-c5e8-7c8a-9cad-ebaf8b55959e_terseLabel_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation</link:label>
    <link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_label_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:to="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance_019f7115-c76d-746e-8189-7cd9cb38076e_terseLabel_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contributions from Tax Equity Investors, net</link:label>
    <link:label id="lab_cik0001563922_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance_label_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Increase (Decrease) From Subsidiary Equity Issuance</link:label>
    <link:label id="lab_cik0001563922_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance_documentation_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Increase (Decrease) From Subsidiary Equity Issuance</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance" xlink:to="lab_cik0001563922_NoncontrollingInterestIncreaseDecreaseFromSubsidiaryEquityIssuance" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfSaleLeasebackTransactionsTextBlock_019f7115-c6fc-78ff-9bd7-38c93731c8ee_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfSaleLeasebackTransactionsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Failed Sale Leaseback Transactions</link:label>
    <link:label id="lab_us-gaap_ScheduleOfSaleLeasebackTransactionsTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfSaleLeasebackTransactionsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transactions [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSaleLeasebackTransactionsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSaleLeasebackTransactionsTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfSaleLeasebackTransactionsTextBlock" xlink:to="lab_us-gaap_ScheduleOfSaleLeasebackTransactionsTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems_019f7115-c6fc-7eaf-b640-d77025c96abd_terseLabel_en-US" xlink:label="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule Of Finite-Lived Out-of-Market Contracts, Intangible Liabilities [Line Items]</link:label>
    <link:label id="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems_label_en-US" xlink:label="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule Of Finite-Lived Out-of-Market Contracts, Intangible Liabilities [Line Items]</link:label>
    <link:label id="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems_documentation_en-US" xlink:label="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Schedule Of Finite-Lived Out-of-Market Contracts, Intangible Liabilities [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems" xlink:to="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NumberOfOperationalWindProjectImpairments_019f7115-c671-710b-a27d-403a29c53c2f_terseLabel_en-US" xlink:label="lab_cik0001563922_NumberOfOperationalWindProjectImpairments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of operational wind project impairments</link:label>
    <link:label id="lab_cik0001563922_NumberOfOperationalWindProjectImpairments_label_en-US" xlink:label="lab_cik0001563922_NumberOfOperationalWindProjectImpairments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number of Operational Wind Project Impairments</link:label>
    <link:label id="lab_cik0001563922_NumberOfOperationalWindProjectImpairments_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfOperationalWindProjectImpairments" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number of Operational Wind Project Impairments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NumberOfOperationalWindProjectImpairments" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NumberOfOperationalWindProjectImpairments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NumberOfOperationalWindProjectImpairments" xlink:to="lab_cik0001563922_NumberOfOperationalWindProjectImpairments" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentAmount_019f7115-c6fc-739a-baf0-5ec912e1b4c1_terseLabel_en-US" xlink:label="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Nontaxable parent - GREC LLC treated as a partnership for U.S. tax purposes</link:label>
    <link:label id="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentAmount_label_en-US" xlink:label="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Nontaxable Parent, Amount</link:label>
    <link:label id="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentAmount_documentation_en-US" xlink:label="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentAmount" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Nontaxable Parent, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentAmount" xlink:href="cik0001563922-20260810.xsd#cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentAmount" xlink:to="lab_cik0001563922_EffectiveIncomeTaxRateReconciliationNontaxableParentAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour_019f7115-c6fc-7f9f-95dc-5b8e022bd2c2_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2029-2030</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, to be Paid, Rolling Year Four</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsAbstract_019f7115-c5e8-7885-a097-fb6945a38e8d_verboseLabel_en-US" xlink:label="lab_us-gaap_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Assets</link:label>
    <link:label id="lab_us-gaap_AssetsAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Assets [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsAbstract" xlink:to="lab_us-gaap_AssetsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CreditFacilityAxis_019f7115-c671-7cb6-ab37-51891a5c20e2_terseLabel_en-US" xlink:label="lab_us-gaap_CreditFacilityAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Credit Facility [Axis]</link:label>
    <link:label id="lab_us-gaap_CreditFacilityAxis_label_en-US" xlink:label="lab_us-gaap_CreditFacilityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Credit Facility [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CreditFacilityAxis" xlink:to="lab_us-gaap_CreditFacilityAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearTwo_019f7115-c6fc-7357-ae52-92e3eea9a961_terseLabel_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2027-2028</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearTwo_label_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, Rolling Year Two</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearTwo_documentation_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, Rolling Year Two</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearTwo" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearTwo"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearTwo" xlink:to="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearTwo" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentAxis_019f7115-c671-7190-b2d2-db721a144590_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument [Axis]</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentAxis_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentAxis" xlink:to="lab_us-gaap_DebtInstrumentAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019f7115-c671-7f29-9390-7c92b40edc29_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Forfeited (in dollars per share)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CreditFacilityDomain_019f7115-c6fc-7b27-b61a-2a1951e7cdd9_terseLabel_en-US" xlink:label="lab_us-gaap_CreditFacilityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Credit Facility [Domain]</link:label>
    <link:label id="lab_us-gaap_CreditFacilityDomain_label_en-US" xlink:label="lab_us-gaap_CreditFacilityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Credit Facility [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CreditFacilityDomain" xlink:to="lab_us-gaap_CreditFacilityDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DisposalGroupNotDiscontinuedOperationOfInterestInConsolidatedSubsidiariesOutstandingPrincipal_019f7115-c554-7346-a43e-115a7f19be8f_terseLabel_en-US" xlink:label="lab_cik0001563922_DisposalGroupNotDiscontinuedOperationOfInterestInConsolidatedSubsidiariesOutstandingPrincipal" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Disposal of interest in consolidated subsidiaries, outstanding principal</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupNotDiscontinuedOperationOfInterestInConsolidatedSubsidiariesOutstandingPrincipal_label_en-US" xlink:label="lab_cik0001563922_DisposalGroupNotDiscontinuedOperationOfInterestInConsolidatedSubsidiariesOutstandingPrincipal" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group Not Discontinued Operation Of Interest In Consolidated Subsidiaries, Outstanding Principal</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupNotDiscontinuedOperationOfInterestInConsolidatedSubsidiariesOutstandingPrincipal_documentation_en-US" xlink:label="lab_cik0001563922_DisposalGroupNotDiscontinuedOperationOfInterestInConsolidatedSubsidiariesOutstandingPrincipal" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disposal Group Not Discontinued Operation Of Interest In Consolidated Subsidiaries, Outstanding Principal</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DisposalGroupNotDiscontinuedOperationOfInterestInConsolidatedSubsidiariesOutstandingPrincipal" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DisposalGroupNotDiscontinuedOperationOfInterestInConsolidatedSubsidiariesOutstandingPrincipal"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DisposalGroupNotDiscontinuedOperationOfInterestInConsolidatedSubsidiariesOutstandingPrincipal" xlink:to="lab_cik0001563922_DisposalGroupNotDiscontinuedOperationOfInterestInConsolidatedSubsidiariesOutstandingPrincipal" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFour_019f7115-c5e8-7ebb-923b-1919428058b3_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2029-2030</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFour_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, Rolling Year Four</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFour_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFour" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, Rolling Year Four</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFour" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFour"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFour" xlink:to="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearFour" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CashFlowLesseeAbstract_019f7115-c671-7507-83a7-b2828446d819_terseLabel_en-US" xlink:label="lab_cik0001563922_CashFlowLesseeAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other information</link:label>
    <link:label id="lab_cik0001563922_CashFlowLesseeAbstract_label_en-US" xlink:label="lab_cik0001563922_CashFlowLesseeAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash Flow, Lessee [Abstract]</link:label>
    <link:label id="lab_cik0001563922_CashFlowLesseeAbstract_documentation_en-US" xlink:label="lab_cik0001563922_CashFlowLesseeAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cash Flow, Lessee</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CashFlowLesseeAbstract" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CashFlowLesseeAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CashFlowLesseeAbstract" xlink:to="lab_cik0001563922_CashFlowLesseeAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage_019f7115-c5e8-7e00-8825-10b0c8140318_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest rate</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Interest Rate, Stated Percentage</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019f7115-c554-7317-ad55-0b1d38882f05_terseLabel_en-US" xlink:label="lab_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investment, Name [Axis]</link:label>
    <link:label id="lab_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_label_en-US" xlink:label="lab_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investment, Name [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:to="lab_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ReclassificationsOfTemporaryEquityToPermanentShares_019f7115-c671-7bb5-9b9f-417997ae9d9d_terseLabel_en-US" xlink:label="lab_cik0001563922_ReclassificationsOfTemporaryEquityToPermanentShares" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Reclassifications of temporary equity to permanent (in shares)</link:label>
    <link:label id="lab_cik0001563922_ReclassificationsOfTemporaryEquityToPermanentShares_label_en-US" xlink:label="lab_cik0001563922_ReclassificationsOfTemporaryEquityToPermanentShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reclassifications Of Temporary Equity To Permanent, Shares</link:label>
    <link:label id="lab_cik0001563922_ReclassificationsOfTemporaryEquityToPermanentShares_documentation_en-US" xlink:label="lab_cik0001563922_ReclassificationsOfTemporaryEquityToPermanentShares" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Reclassifications Of Temporary Equity To Permanent, Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ReclassificationsOfTemporaryEquityToPermanentShares" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ReclassificationsOfTemporaryEquityToPermanentShares"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ReclassificationsOfTemporaryEquityToPermanentShares" xlink:to="lab_cik0001563922_ReclassificationsOfTemporaryEquityToPermanentShares" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesPriorFourFiscalQuarters_019f7115-c671-7485-ae35-bfdb097b1182_terseLabel_en-US" xlink:label="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesPriorFourFiscalQuarters" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock repurchase limit, percentage of weighted average number of Shares prior four fiscal quarters</link:label>
    <link:label id="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesPriorFourFiscalQuarters_label_en-US" xlink:label="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesPriorFourFiscalQuarters" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Repurchase Program, Stock Repurchase Limit, Percentage Of Weighted Average Number Of Shares Prior Four Fiscal Quarters</link:label>
    <link:label id="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesPriorFourFiscalQuarters_documentation_en-US" xlink:label="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesPriorFourFiscalQuarters" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Stock Repurchase Program, Stock Repurchase Limit, Percentage Of Weighted Average Number Of Shares Prior Four Fiscal Quarters</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesPriorFourFiscalQuarters" xlink:href="cik0001563922-20260810.xsd#cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesPriorFourFiscalQuarters"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesPriorFourFiscalQuarters" xlink:to="lab_cik0001563922_StockRepurchaseProgramStockRepurchaseLimitPercentageOfWeightedAverageNumberOfSharesPriorFourFiscalQuarters" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ManagementServiceIncentiveMember_019f7115-c671-7115-94f4-9314e4529da6_terseLabel_en-US" xlink:label="lab_us-gaap_ManagementServiceIncentiveMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Performance participation fee</link:label>
    <link:label id="lab_us-gaap_ManagementServiceIncentiveMember_label_en-US" xlink:label="lab_us-gaap_ManagementServiceIncentiveMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Management Service, Incentive [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementServiceIncentiveMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManagementServiceIncentiveMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ManagementServiceIncentiveMember" xlink:to="lab_us-gaap_ManagementServiceIncentiveMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseLiabilityNoncurrent_019f7115-c554-783b-bae2-4a5b53f2822d_verboseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Operating lease liabilities</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLiabilityNoncurrent_019f7115-c554-7965-af3a-56ebcc975cc2_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Operating lease liabilities, noncurrent</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLiabilityNoncurrent_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Liability, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="lab_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SettlementAgreementForfeitedPaymentsAmount_019f7115-c6fc-78ff-ba1e-615d69089a2e_terseLabel_en-US" xlink:label="lab_cik0001563922_SettlementAgreementForfeitedPaymentsAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Payment for obligations</link:label>
    <link:label id="lab_cik0001563922_SettlementAgreementForfeitedPaymentsAmount_label_en-US" xlink:label="lab_cik0001563922_SettlementAgreementForfeitedPaymentsAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Settlement Agreement, Forfeited Payments, Amount</link:label>
    <link:label id="lab_cik0001563922_SettlementAgreementForfeitedPaymentsAmount_documentation_en-US" xlink:label="lab_cik0001563922_SettlementAgreementForfeitedPaymentsAmount" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Settlement Agreement, Forfeited Payments, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SettlementAgreementForfeitedPaymentsAmount" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SettlementAgreementForfeitedPaymentsAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SettlementAgreementForfeitedPaymentsAmount" xlink:to="lab_cik0001563922_SettlementAgreementForfeitedPaymentsAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent_019f7115-c671-7b04-9dc3-e2e449ca09b3_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, plant and equipment, net</link:label>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent_label_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent" xlink:to="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree_019f7115-c671-7152-b327-b002c313c496_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2028-2029</link:label>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Rolling Year Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree"/>
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    <link:label id="lab_us-gaap_DepreciationAmortizationAndAccretionNet_019f7115-c76d-78d3-8512-05cdaaea9aa7_verboseLabel_en-US" xlink:label="lab_us-gaap_DepreciationAmortizationAndAccretionNet" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Depreciation, amortization and accretion</link:label>
    <link:label id="lab_us-gaap_DepreciationAmortizationAndAccretionNet_label_en-US" xlink:label="lab_us-gaap_DepreciationAmortizationAndAccretionNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Depreciation, Amortization and Accretion, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAmortizationAndAccretionNet" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationAmortizationAndAccretionNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DepreciationAmortizationAndAccretionNet" xlink:to="lab_us-gaap_DepreciationAmortizationAndAccretionNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentAbstract_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityRegistrantName_019f7115-c671-7b6b-b942-a6d2b07552dc_terseLabel_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:label id="lab_dei_EntityRegistrantName_label_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityRegistrantName" xlink:to="lab_dei_EntityRegistrantName" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTableTextBlock_019f7115-c5e8-7b99-bc7c-ade0c68fc05e_terseLabel_en-US" xlink:label="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Out-of-market Contracts</link:label>
    <link:label id="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTableTextBlock_label_en-US" xlink:label="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule Of Finite-Lived Out-of-Market Contracts, Intangible Liabilities [Table Text Block]</link:label>
    <link:label id="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTableTextBlock_documentation_en-US" xlink:label="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Schedule Of Finite-Lived Out-of-Market Contracts, Intangible Liabilities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTableTextBlock" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTableTextBlock" xlink:to="lab_cik0001563922_ScheduleOfFiniteLivedOutOfMarketContractsIntangibleLiabilitiesTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_TemporaryEquitySharesOutstanding_019f7115-c5e8-701e-9179-dc6bb550e792_periodStartLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Redeemable common shares, beginning balance (in shares)</link:label>
    <link:label id="lab_us-gaap_TemporaryEquitySharesOutstanding_019f7115-c5e8-7623-8ad9-4827dd7824b3_periodEndLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Redeemable common shares, ending balance (in shares)</link:label>
    <link:label id="lab_us-gaap_TemporaryEquitySharesOutstanding_label_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Shares Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesOutstanding"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquitySharesOutstanding" xlink:to="lab_us-gaap_TemporaryEquitySharesOutstanding" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths_019f7115-c671-7270-ad7f-d77ca7e3d306_verboseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">2026-2027</link:label>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths_019f7115-c671-7bc8-9178-c55f1566f074_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026</link:label>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Next Rolling 12 Months</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_A2023EquityIncentivePlanMember_019f7115-c76d-7a1d-ae1d-5a727fe8d761_terseLabel_en-US" xlink:label="lab_cik0001563922_A2023EquityIncentivePlanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2023 Equity Incentive Plan</link:label>
    <link:label id="lab_cik0001563922_A2023EquityIncentivePlanMember_label_en-US" xlink:label="lab_cik0001563922_A2023EquityIncentivePlanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">2023 Equity Incentive Plan [Member]</link:label>
    <link:label id="lab_cik0001563922_A2023EquityIncentivePlanMember_documentation_en-US" xlink:label="lab_cik0001563922_A2023EquityIncentivePlanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">2023 Equity Incentive Plan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_A2023EquityIncentivePlanMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_A2023EquityIncentivePlanMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_A2023EquityIncentivePlanMember" xlink:to="lab_cik0001563922_A2023EquityIncentivePlanMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_019f7115-c671-7304-99c2-fe2d89591113_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Disposal group, including discontinued operation, liabilities</link:label>
    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_019f7115-c671-7287-94a8-5a576c01944a_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total liabilities</link:label>
    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_label_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Liabilities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsFinancingObligation_019f7115-c5e8-74d8-b689-2f36562056ad_terseLabel_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsFinancingObligation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Origination costs</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsFinancingObligation_label_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsFinancingObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction Origination Costs, Financing Obligation</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsFinancingObligation_documentation_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsFinancingObligation" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction Origination Costs, Financing Obligation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsFinancingObligation" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FailedSaleLeasebackTransactionOriginationCostsFinancingObligation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsFinancingObligation" xlink:to="lab_cik0001563922_FailedSaleLeasebackTransactionOriginationCostsFinancingObligation" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearTwo_019f7115-c5e8-71db-81c6-91e6809743a3_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2027-2028</link:label>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearTwo_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Maturities, Repayments of Principal in Rolling Year Two</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearTwo"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearTwo" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearTwo" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_019f7115-c6fc-7744-818f-8eca28687d27_terseLabel_en-US" xlink:label="lab_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]</link:label>
    <link:label id="lab_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_label_en-US" xlink:label="lab_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:to="lab_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_019f7115-c671-71ef-92ee-21795bfe5a83_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Distributions to noncontrolling interests</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_label_en-US" xlink:label="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Noncontrolling Interest, Decrease From Distributions To Noncontrolling Interest Holders</link:label>
    <link:label id="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_documentation_en-US" xlink:label="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Temporary Equity, Noncontrolling Interest, Decrease From Distributions To Noncontrolling Interest Holders</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:to="lab_cik0001563922_TemporaryEquityNoncontrollingInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NumberOfOperatingSegments_019f7115-c76d-7af6-99cf-65d32045a93d_terseLabel_en-US" xlink:label="lab_us-gaap_NumberOfOperatingSegments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of operating segments</link:label>
    <link:label id="lab_us-gaap_NumberOfOperatingSegments_label_en-US" xlink:label="lab_us-gaap_NumberOfOperatingSegments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number of Operating Segments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NumberOfOperatingSegments" xlink:to="lab_us-gaap_NumberOfOperatingSegments" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_019f7115-c6fc-7faa-bb20-2948e5e0dc8c_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Finance right-of-use asset</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_019f7115-c6fc-7720-831a-9125bcdee092_verboseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Property, plant and equipment, at cost</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Right-of-Use Asset, before Accumulated Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization" xlink:to="lab_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeCostOfHedge_019f7115-c5e8-7564-9043-8151eba9b098_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeCostOfHedge" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative, cost of hedge</link:label>
    <link:label id="lab_us-gaap_DerivativeCostOfHedge_019f7115-c5e8-7b9d-adba-75b7a4974c78_verboseLabel_en-US" xlink:label="lab_us-gaap_DerivativeCostOfHedge" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Premium price</link:label>
    <link:label id="lab_us-gaap_DerivativeCostOfHedge_label_en-US" xlink:label="lab_us-gaap_DerivativeCostOfHedge" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative, Cost of Hedge</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCostOfHedge" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeCostOfHedge"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeCostOfHedge" xlink:to="lab_us-gaap_DerivativeCostOfHedge" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_EarnoutPeriodTrancheOneMember_019f7115-c6fc-7abd-b357-1ffb3a816ced_terseLabel_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodTrancheOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tranche 1 Earnout Shares</link:label>
    <link:label id="lab_cik0001563922_EarnoutPeriodTrancheOneMember_label_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodTrancheOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Earnout Period, Tranche One [Member]</link:label>
    <link:label id="lab_cik0001563922_EarnoutPeriodTrancheOneMember_documentation_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodTrancheOneMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Earnout Period, Tranche One</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_EarnoutPeriodTrancheOneMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_EarnoutPeriodTrancheOneMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_EarnoutPeriodTrancheOneMember" xlink:to="lab_cik0001563922_EarnoutPeriodTrancheOneMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019f7115-c5e8-7383-9cbd-e391aeccabee_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Granted, Weighted Average Fair Value (in dollars per share)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019f7115-c76d-7526-9686-3da33956537c_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Related Party [Axis]</link:label>
    <link:label id="lab_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_label_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related and Nonrelated Parties [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="lab_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidNextRolling12Months_019f7115-c555-724a-9012-458a89992083_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidNextRolling12Months" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026-2027</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidNextRolling12Months_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidNextRolling12Months" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, Next Rolling 12 Months</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidNextRolling12Months_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidNextRolling12Months" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, Next Rolling 12 Months</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidNextRolling12Months" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidNextRolling12Months"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidNextRolling12Months" xlink:to="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidNextRolling12Months" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ContractAmortizationMember_019f7115-c555-7c57-b28c-0d55a46aa3e3_terseLabel_en-US" xlink:label="lab_cik0001563922_ContractAmortizationMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contract amortization, net</link:label>
    <link:label id="lab_cik0001563922_ContractAmortizationMember_019f7115-c555-7ccc-9f08-8b859579555c_verboseLabel_en-US" xlink:label="lab_cik0001563922_ContractAmortizationMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Contract amortization, net</link:label>
    <link:label id="lab_cik0001563922_ContractAmortizationMember_019f7115-c555-78dd-bd75-db47a120f9f7_netLabel_en-US" xlink:label="lab_cik0001563922_ContractAmortizationMember" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xml:lang="en-US">Contract amortization, net</link:label>
    <link:label id="lab_cik0001563922_ContractAmortizationMember_label_en-US" xlink:label="lab_cik0001563922_ContractAmortizationMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract Amortization [Member]</link:label>
    <link:label id="lab_cik0001563922_ContractAmortizationMember_documentation_en-US" xlink:label="lab_cik0001563922_ContractAmortizationMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Contract Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ContractAmortizationMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ContractAmortizationMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ContractAmortizationMember" xlink:to="lab_cik0001563922_ContractAmortizationMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporary_019f7115-c671-7fe1-8ef7-6bece2235557_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporary" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Earnout Share participation reclassification to temporary equity</link:label>
    <link:label id="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporary_label_en-US" xlink:label="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporary" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reclassifications Of Permanent Equity To Temporary</link:label>
    <link:label id="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporary_documentation_en-US" xlink:label="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporary" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Reclassifications Of Permanent Equity To Temporary</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ReclassificationsOfPermanentEquityToTemporary" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ReclassificationsOfPermanentEquityToTemporary"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ReclassificationsOfPermanentEquityToTemporary" xlink:to="lab_cik0001563922_ReclassificationsOfPermanentEquityToTemporary" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_019f7115-c671-718d-abad-4e57de131b6d_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Intangible Assets</link:label>
    <link:label id="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Finite-Lived Intangible Assets [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DebtInstrumentInterestRateIfPrepaidPercentage_019f7115-c5e8-701b-9e6b-bd54976fc94b_terseLabel_en-US" xlink:label="lab_cik0001563922_DebtInstrumentInterestRateIfPrepaidPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest rate if prepaid, percentage</link:label>
    <link:label id="lab_cik0001563922_DebtInstrumentInterestRateIfPrepaidPercentage_label_en-US" xlink:label="lab_cik0001563922_DebtInstrumentInterestRateIfPrepaidPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Interest Rate If Prepaid, Percentage</link:label>
    <link:label id="lab_cik0001563922_DebtInstrumentInterestRateIfPrepaidPercentage_documentation_en-US" xlink:label="lab_cik0001563922_DebtInstrumentInterestRateIfPrepaidPercentage" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Interest Rate If Prepaid, Percentage</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DebtInstrumentInterestRateIfPrepaidPercentage" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DebtInstrumentInterestRateIfPrepaidPercentage"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DebtInstrumentInterestRateIfPrepaidPercentage" xlink:to="lab_cik0001563922_DebtInstrumentInterestRateIfPrepaidPercentage" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredForeignIncomeTaxExpenseBenefit_019f7115-c6fc-72d3-8923-252710950e93_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Foreign</link:label>
    <link:label id="lab_us-gaap_DeferredForeignIncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Foreign Income Tax Expense (Benefit)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:to="lab_us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccountsReceivableMember_019f7115-c671-7f68-aeff-6231d23bcae4_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsReceivableMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounts Receivable</link:label>
    <link:label id="lab_us-gaap_AccountsReceivableMember_label_en-US" xlink:label="lab_us-gaap_AccountsReceivableMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts Receivable [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsReceivableMember" xlink:to="lab_us-gaap_AccountsReceivableMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PaymentsforAssetAcquisitions_019f7115-c6fc-7e77-8c7b-9568f461a8ea_terseLabel_en-US" xlink:label="lab_cik0001563922_PaymentsforAssetAcquisitions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Payments for asset acquisitions</link:label>
    <link:label id="lab_cik0001563922_PaymentsforAssetAcquisitions_label_en-US" xlink:label="lab_cik0001563922_PaymentsforAssetAcquisitions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments for Asset Acquisitions</link:label>
    <link:label id="lab_cik0001563922_PaymentsforAssetAcquisitions_documentation_en-US" xlink:label="lab_cik0001563922_PaymentsforAssetAcquisitions" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Payments for Asset Acquisitions</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PaymentsforAssetAcquisitions" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PaymentsforAssetAcquisitions"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PaymentsforAssetAcquisitions" xlink:to="lab_cik0001563922_PaymentsforAssetAcquisitions" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance_019f7115-c6fc-7adc-b3d0-26f65c514e60_verboseLabel_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Contributions from noncontrolling interests, net</link:label>
    <link:label id="lab_us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance_label_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Increase from Subsidiary Equity Issuance</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance" xlink:to="lab_us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_019f7115-c5e8-75bd-96d3-6d460cb15de1_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other capital activity</link:label>
    <link:label id="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_label_en-US" xlink:label="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from (Payment for) Other Financing Activity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:to="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DerivativeInstrumentTerminationProceedsToRepayLoan_019f7115-c554-78c9-b2bf-8bc199eb9b86_terseLabel_en-US" xlink:label="lab_cik0001563922_DerivativeInstrumentTerminationProceedsToRepayLoan" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds to repay loan</link:label>
    <link:label id="lab_cik0001563922_DerivativeInstrumentTerminationProceedsToRepayLoan_label_en-US" xlink:label="lab_cik0001563922_DerivativeInstrumentTerminationProceedsToRepayLoan" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Instrument, Termination, Proceeds To Repay Loan</link:label>
    <link:label id="lab_cik0001563922_DerivativeInstrumentTerminationProceedsToRepayLoan_documentation_en-US" xlink:label="lab_cik0001563922_DerivativeInstrumentTerminationProceedsToRepayLoan" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Derivative Instrument, Termination, Proceeds To Repay Loan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DerivativeInstrumentTerminationProceedsToRepayLoan" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DerivativeInstrumentTerminationProceedsToRepayLoan"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DerivativeInstrumentTerminationProceedsToRepayLoan" xlink:to="lab_cik0001563922_DerivativeInstrumentTerminationProceedsToRepayLoan" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems_019f7115-c671-7c20-9b7a-b4b0013d6441_terseLabel_en-US" xlink:label="lab_cik0001563922_FiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Finite-Lived Out-of-Market Contracts, Intangible Liabilities [Line Items]</link:label>
    <link:label id="lab_cik0001563922_FiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems_label_en-US" xlink:label="lab_cik0001563922_FiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Out-of-Market Contracts, Intangible Liabilities [Line Items]</link:label>
    <link:label id="lab_cik0001563922_FiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems_documentation_en-US" xlink:label="lab_cik0001563922_FiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Schedule Of Finite-Lived Out-of-Market Contracts, Intangible Liabilities [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FiniteLivedOutOfMarketContractsIntangibleLiabilitiesLineItems"/>
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    <link:label id="lab_cik0001563922_NewMarketLoanMember_019f7115-c671-74f0-9cea-026c735a2226_terseLabel_en-US" xlink:label="lab_cik0001563922_NewMarketLoanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">New Market(1)</link:label>
    <link:label id="lab_cik0001563922_NewMarketLoanMember_label_en-US" xlink:label="lab_cik0001563922_NewMarketLoanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">New Market Loan [Member]</link:label>
    <link:label id="lab_cik0001563922_NewMarketLoanMember_documentation_en-US" xlink:label="lab_cik0001563922_NewMarketLoanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">New Market Loan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NewMarketLoanMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NewMarketLoanMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NewMarketLoanMember" xlink:to="lab_cik0001563922_NewMarketLoanMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SharesWithheldRelatedToNetShareSettlementOfEquityAwards_019f7115-c6fc-7018-aaf0-42a9d6dae210_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_SharesWithheldRelatedToNetShareSettlementOfEquityAwards" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Shares withheld related to net share settlement of equity awards</link:label>
    <link:label id="lab_cik0001563922_SharesWithheldRelatedToNetShareSettlementOfEquityAwards_label_en-US" xlink:label="lab_cik0001563922_SharesWithheldRelatedToNetShareSettlementOfEquityAwards" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares Withheld Related to Net Share Settlement of Equity Awards</link:label>
    <link:label id="lab_cik0001563922_SharesWithheldRelatedToNetShareSettlementOfEquityAwards_documentation_en-US" xlink:label="lab_cik0001563922_SharesWithheldRelatedToNetShareSettlementOfEquityAwards" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Shares Withheld Related to Net Share Settlement of Equity Awards</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SharesWithheldRelatedToNetShareSettlementOfEquityAwards" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SharesWithheldRelatedToNetShareSettlementOfEquityAwards"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SharesWithheldRelatedToNetShareSettlementOfEquityAwards" xlink:to="lab_cik0001563922_SharesWithheldRelatedToNetShareSettlementOfEquityAwards" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermPurchaseCommitmentAmount_019f7115-c5e8-7c18-af63-0ea237344e89_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermPurchaseCommitmentAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Funding commitment</link:label>
    <link:label id="lab_us-gaap_LongTermPurchaseCommitmentAmount_label_en-US" xlink:label="lab_us-gaap_LongTermPurchaseCommitmentAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Purchase Commitment, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermPurchaseCommitmentAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermPurchaseCommitmentAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermPurchaseCommitmentAmount" xlink:to="lab_us-gaap_LongTermPurchaseCommitmentAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MinorityInterestDecreaseFromRedemptions_019f7115-c671-7a6c-9c0f-186c0f3b8252_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_MinorityInterestDecreaseFromRedemptions" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Buyout of noncontrolling interests</link:label>
    <link:label id="lab_us-gaap_MinorityInterestDecreaseFromRedemptions_label_en-US" xlink:label="lab_us-gaap_MinorityInterestDecreaseFromRedemptions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromRedemptions" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestDecreaseFromRedemptions"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MinorityInterestDecreaseFromRedemptions" xlink:to="lab_us-gaap_MinorityInterestDecreaseFromRedemptions" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SecuredDebtTrancheAMember_019f7115-c671-7fcd-90ab-9ec871a77b67_terseLabel_en-US" xlink:label="lab_cik0001563922_SecuredDebtTrancheAMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Secured Debt Tranche A</link:label>
    <link:label id="lab_cik0001563922_SecuredDebtTrancheAMember_label_en-US" xlink:label="lab_cik0001563922_SecuredDebtTrancheAMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Secured Debt Tranche A [Member]</link:label>
    <link:label id="lab_cik0001563922_SecuredDebtTrancheAMember_documentation_en-US" xlink:label="lab_cik0001563922_SecuredDebtTrancheAMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Secured Debt Tranche A</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SecuredDebtTrancheAMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SecuredDebtTrancheAMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SecuredDebtTrancheAMember" xlink:to="lab_cik0001563922_SecuredDebtTrancheAMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentFaceAmount_019f7115-c671-7b83-9c41-b28077afcac2_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentFaceAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Face amount of debt</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentFaceAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentFaceAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Face Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentFaceAmount" xlink:to="lab_us-gaap_DebtInstrumentFaceAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RedeemableCommonSharesCommonClassEarnoutMember_019f7115-c671-72fa-80ae-2738f433f11e_terseLabel_en-US" xlink:label="lab_cik0001563922_RedeemableCommonSharesCommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Redeemable Common Shares, Common Class Earnout</link:label>
    <link:label id="lab_cik0001563922_RedeemableCommonSharesCommonClassEarnoutMember_label_en-US" xlink:label="lab_cik0001563922_RedeemableCommonSharesCommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Redeemable Common Shares, Common Class Earnout [Member]</link:label>
    <link:label id="lab_cik0001563922_RedeemableCommonSharesCommonClassEarnoutMember_documentation_en-US" xlink:label="lab_cik0001563922_RedeemableCommonSharesCommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Redeemable Common Shares, Common Class Earnout</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RedeemableCommonSharesCommonClassEarnoutMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RedeemableCommonSharesCommonClassEarnoutMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RedeemableCommonSharesCommonClassEarnoutMember" xlink:to="lab_cik0001563922_RedeemableCommonSharesCommonClassEarnoutMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Comprehensive Income [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FairValueAndInvestmentsDisclosureTextBlock_019f7115-c555-7b13-9d29-52dc1b4ddadd_terseLabel_en-US" xlink:label="lab_cik0001563922_FairValueAndInvestmentsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Measurements and Investments</link:label>
    <link:label id="lab_cik0001563922_FairValueAndInvestmentsDisclosureTextBlock_label_en-US" xlink:label="lab_cik0001563922_FairValueAndInvestmentsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value And Investments Disclosure [Text Block]</link:label>
    <link:label id="lab_cik0001563922_FairValueAndInvestmentsDisclosureTextBlock_documentation_en-US" xlink:label="lab_cik0001563922_FairValueAndInvestmentsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fair Value And Investments Disclosure</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FairValueAndInvestmentsDisclosureTextBlock" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FairValueAndInvestmentsDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FairValueAndInvestmentsDisclosureTextBlock" xlink:to="lab_cik0001563922_FairValueAndInvestmentsDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AssetAcquisitionLiabilityAssumed_019f7115-c6fc-7940-90e3-5f8f40f81a6a_terseLabel_en-US" xlink:label="lab_cik0001563922_AssetAcquisitionLiabilityAssumed" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Asset acquisition, liability assumed</link:label>
    <link:label id="lab_cik0001563922_AssetAcquisitionLiabilityAssumed_label_en-US" xlink:label="lab_cik0001563922_AssetAcquisitionLiabilityAssumed" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Acquisition, Liability Assumed</link:label>
    <link:label id="lab_cik0001563922_AssetAcquisitionLiabilityAssumed_documentation_en-US" xlink:label="lab_cik0001563922_AssetAcquisitionLiabilityAssumed" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Asset Acquisition, Liability Assumed</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AssetAcquisitionLiabilityAssumed" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AssetAcquisitionLiabilityAssumed"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_AssetAcquisitionLiabilityAssumed" xlink:to="lab_cik0001563922_AssetAcquisitionLiabilityAssumed" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NumberOfIncomeTaxJurisdictions_019f7115-c671-7522-9565-e3c17eec7217_terseLabel_en-US" xlink:label="lab_cik0001563922_NumberOfIncomeTaxJurisdictions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of jurisdictions in which the company operates</link:label>
    <link:label id="lab_cik0001563922_NumberOfIncomeTaxJurisdictions_label_en-US" xlink:label="lab_cik0001563922_NumberOfIncomeTaxJurisdictions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number Of Income Tax Jurisdictions</link:label>
    <link:label id="lab_cik0001563922_NumberOfIncomeTaxJurisdictions_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfIncomeTaxJurisdictions" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number Of Income Tax Jurisdictions</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NumberOfIncomeTaxJurisdictions" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NumberOfIncomeTaxJurisdictions"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NumberOfIncomeTaxJurisdictions" xlink:to="lab_cik0001563922_NumberOfIncomeTaxJurisdictions" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ValuationAllowanceTable_019f7115-c6fc-7ed9-b099-48d3809bea7d_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowanceTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred Tax Asset, Valuation Allowance [Table]</link:label>
    <link:label id="lab_us-gaap_ValuationAllowanceTable_label_en-US" xlink:label="lab_us-gaap_ValuationAllowanceTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Asset, Valuation Allowance [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationAllowanceTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ValuationAllowanceTable" xlink:to="lab_us-gaap_ValuationAllowanceTable" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ContingentConsiderationLiabilityMember_019f7115-c671-74bd-853f-ca342711c8fd_terseLabel_en-US" xlink:label="lab_cik0001563922_ContingentConsiderationLiabilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contingent consideration</link:label>
    <link:label id="lab_cik0001563922_ContingentConsiderationLiabilityMember_label_en-US" xlink:label="lab_cik0001563922_ContingentConsiderationLiabilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contingent Consideration Liability [Member]</link:label>
    <link:label id="lab_cik0001563922_ContingentConsiderationLiabilityMember_documentation_en-US" xlink:label="lab_cik0001563922_ContingentConsiderationLiabilityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Contingent Consideration Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ContingentConsiderationLiabilityMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ContingentConsiderationLiabilityMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ContingentConsiderationLiabilityMember" xlink:to="lab_cik0001563922_ContingentConsiderationLiabilityMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DegradationInProductionMember_019f7115-c6fc-79f9-8556-35ba5a5ce304_terseLabel_en-US" xlink:label="lab_cik0001563922_DegradationInProductionMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Degradation in Production</link:label>
    <link:label id="lab_cik0001563922_DegradationInProductionMember_label_en-US" xlink:label="lab_cik0001563922_DegradationInProductionMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Degradation In Production [Member]</link:label>
    <link:label id="lab_cik0001563922_DegradationInProductionMember_documentation_en-US" xlink:label="lab_cik0001563922_DegradationInProductionMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Degradation In Production</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DegradationInProductionMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DegradationInProductionMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DegradationInProductionMember" xlink:to="lab_cik0001563922_DegradationInProductionMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f7115-c6fc-7308-98f0-ca27ff97e2e6_periodStartLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Unvested balance, beginning balance (in dollars per share)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f7115-c6fc-7d14-9d02-674c0fb39243_periodEndLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Unvested balance, ending balance (in dollars per share)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RestrictedCashNoncurrent_019f7115-c5e8-718a-8d3a-8f9506f35be1_terseLabel_en-US" xlink:label="lab_us-gaap_RestrictedCashNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Restricted cash</link:label>
    <link:label id="lab_us-gaap_RestrictedCashNoncurrent_label_en-US" xlink:label="lab_us-gaap_RestrictedCashNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restricted Cash, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestrictedCashNoncurrent" xlink:to="lab_us-gaap_RestrictedCashNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AociLossCashFlowHedgeCumulativeGainLossAfterTax_019f7115-c671-7006-8605-473219e3392d_terseLabel_en-US" xlink:label="lab_us-gaap_AociLossCashFlowHedgeCumulativeGainLossAfterTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">AOCI, cash flow hedge, cumulative gain (loss), after tax</link:label>
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    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets_019f7115-c5e8-76d9-a100-2bcdfa86dd5f_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other current assets</link:label>
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    <link:label id="lab_cik0001563922_CashFlowNoncashFinancingActivitiesAbstract_019f7115-c6fc-7aef-a829-7fa4e699ae92_terseLabel_en-US" xlink:label="lab_cik0001563922_CashFlowNoncashFinancingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Non-cash financing activities</link:label>
    <link:label id="lab_cik0001563922_CashFlowNoncashFinancingActivitiesAbstract_label_en-US" xlink:label="lab_cik0001563922_CashFlowNoncashFinancingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash Flow, Noncash Financing Activities [Abstract]</link:label>
    <link:label id="lab_cik0001563922_CashFlowNoncashFinancingActivitiesAbstract_documentation_en-US" xlink:label="lab_cik0001563922_CashFlowNoncashFinancingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cash Flow, Noncash Financing Activities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CashFlowNoncashFinancingActivitiesAbstract" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CashFlowNoncashFinancingActivitiesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CashFlowNoncashFinancingActivitiesAbstract" xlink:to="lab_cik0001563922_CashFlowNoncashFinancingActivitiesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsNoncurrent_019f7115-c6fc-7f7f-8652-a88c49606556_totalLabel_en-US" xlink:label="lab_us-gaap_AssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total noncurrent assets</link:label>
    <link:label id="lab_us-gaap_AssetsNoncurrent_label_en-US" xlink:label="lab_us-gaap_AssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Assets, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsNoncurrent" xlink:to="lab_us-gaap_AssetsNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CiderSolarConstructionOwnerLLCMember_019f7115-c671-78a3-b1e4-508e9d5ca5d5_terseLabel_en-US" xlink:label="lab_cik0001563922_CiderSolarConstructionOwnerLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cider Solar Construction Owner LLC</link:label>
    <link:label id="lab_cik0001563922_CiderSolarConstructionOwnerLLCMember_label_en-US" xlink:label="lab_cik0001563922_CiderSolarConstructionOwnerLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cider Solar Construction Owner LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_CiderSolarConstructionOwnerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_CiderSolarConstructionOwnerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cider Solar Construction Owner LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CiderSolarConstructionOwnerLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CiderSolarConstructionOwnerLLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CiderSolarConstructionOwnerLLCMember" xlink:to="lab_cik0001563922_CiderSolarConstructionOwnerLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock_019f7115-c6fc-70d0-979e-1a48ea9cb1e6_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Remaining Performance Obligations</link:label>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock" xlink:to="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SettlementAgreementAdvanceDepositAmountWrittenOff_019f7115-c6fc-72f8-a3db-7abb0a093ce9_terseLabel_en-US" xlink:label="lab_cik0001563922_SettlementAgreementAdvanceDepositAmountWrittenOff" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Loss of direct operating costs</link:label>
    <link:label id="lab_cik0001563922_SettlementAgreementAdvanceDepositAmountWrittenOff_label_en-US" xlink:label="lab_cik0001563922_SettlementAgreementAdvanceDepositAmountWrittenOff" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Settlement Agreement, Advance Deposit, Amount Written Off</link:label>
    <link:label id="lab_cik0001563922_SettlementAgreementAdvanceDepositAmountWrittenOff_documentation_en-US" xlink:label="lab_cik0001563922_SettlementAgreementAdvanceDepositAmountWrittenOff" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Settlement Agreement, Advance Deposit, Amount Written Off</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SettlementAgreementAdvanceDepositAmountWrittenOff" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SettlementAgreementAdvanceDepositAmountWrittenOff"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SettlementAgreementAdvanceDepositAmountWrittenOff" xlink:to="lab_cik0001563922_SettlementAgreementAdvanceDepositAmountWrittenOff" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f7115-c671-7234-a885-09d7495947bd_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV [Domain]</link:label>
    <link:label id="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_label_en-US" xlink:label="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DebtInstrumentPrincipalPaymentNumberOfMonthlyInstallments_019f7115-c6fc-71aa-8c3e-b9d118343f6c_terseLabel_en-US" xlink:label="lab_cik0001563922_DebtInstrumentPrincipalPaymentNumberOfMonthlyInstallments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of monthly installments (in monthly installments)</link:label>
    <link:label id="lab_cik0001563922_DebtInstrumentPrincipalPaymentNumberOfMonthlyInstallments_label_en-US" xlink:label="lab_cik0001563922_DebtInstrumentPrincipalPaymentNumberOfMonthlyInstallments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Principal Payment, Number Of Monthly Installments</link:label>
    <link:label id="lab_cik0001563922_DebtInstrumentPrincipalPaymentNumberOfMonthlyInstallments_documentation_en-US" xlink:label="lab_cik0001563922_DebtInstrumentPrincipalPaymentNumberOfMonthlyInstallments" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Principal Payment, Number Of Monthly Installments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DebtInstrumentPrincipalPaymentNumberOfMonthlyInstallments" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DebtInstrumentPrincipalPaymentNumberOfMonthlyInstallments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DebtInstrumentPrincipalPaymentNumberOfMonthlyInstallments" xlink:to="lab_cik0001563922_DebtInstrumentPrincipalPaymentNumberOfMonthlyInstallments" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BalanceSheetLocationDomain_019f7115-c5e8-74e5-a564-e2d8d910c218_terseLabel_en-US" xlink:label="lab_us-gaap_BalanceSheetLocationDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement of Financial Position Location, Balance [Domain]</link:label>
    <link:label id="lab_us-gaap_BalanceSheetLocationDomain_label_en-US" xlink:label="lab_us-gaap_BalanceSheetLocationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Financial Position Location, Balance [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BalanceSheetLocationDomain" xlink:to="lab_us-gaap_BalanceSheetLocationDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AmortizationOfFinancingCostsAndDiscounts_019f7115-c6fc-7fc8-a4f7-6135237bc695_terseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amortization of financing costs and debt discounts</link:label>
    <link:label id="lab_us-gaap_AmortizationOfFinancingCostsAndDiscounts_label_en-US" xlink:label="lab_us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amortization of Debt Issuance Costs and Discounts</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:to="lab_us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearThree_019f7115-c5e8-766e-9282-addeeeba797b_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2028-2029</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearThree_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, Rolling Year Three</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearThree_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Financing Obligation, To Be Paid, Rolling Year Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearThree" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearThree"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearThree" xlink:to="lab_cik0001563922_SaleLeasebackTransactionFinancingObligationToBePaidRollingYearThree" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsNoncurrentAbstract_019f7115-c5e8-7b50-a894-3d54487876ba_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsNoncurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Noncurrent assets:</link:label>
    <link:label id="lab_us-gaap_AssetsNoncurrentAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsNoncurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Assets, Noncurrent [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsNoncurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsNoncurrentAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsNoncurrentAbstract" xlink:to="lab_us-gaap_AssetsNoncurrentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther_019f7115-c554-7879-ab00-1aca7010496f_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Other tax credits</link:label>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther"/>
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    <link:label id="lab_us-gaap_EarningsPerSharePolicyTextBlock_019f7115-c6fc-7f84-a406-1b61c1a3817b_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerSharePolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earnings per Share</link:label>
    <link:label id="lab_us-gaap_EarningsPerSharePolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_EarningsPerSharePolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Earnings Per Share, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerSharePolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerSharePolicyTextBlock"/>
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    <link:label id="lab_us-gaap_ConsolidationSubsidiariesOrOtherInvestmentsConsolidatedEntitiesPolicy_019f7115-c6fc-71f2-be75-df9848c0ffe0_terseLabel_en-US" xlink:label="lab_us-gaap_ConsolidationSubsidiariesOrOtherInvestmentsConsolidatedEntitiesPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Noncontrolling Interests ("NCI"), RNCI and Hypothetical Liquidation at Book Value ("HLBV")</link:label>
    <link:label id="lab_us-gaap_ConsolidationSubsidiariesOrOtherInvestmentsConsolidatedEntitiesPolicy_label_en-US" xlink:label="lab_us-gaap_ConsolidationSubsidiariesOrOtherInvestmentsConsolidatedEntitiesPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsolidationSubsidiariesOrOtherInvestmentsConsolidatedEntitiesPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConsolidationSubsidiariesOrOtherInvestmentsConsolidatedEntitiesPolicy"/>
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    <link:label id="lab_us-gaap_AssetRetirementObligationAccretionExpense_019f7115-c6fc-7b5a-a6a6-cc1918f3084a_terseLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationAccretionExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accretion expense</link:label>
    <link:label id="lab_us-gaap_AssetRetirementObligationAccretionExpense_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationAccretionExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Retirement Obligation, Accretion Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationAccretionExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetRetirementObligationAccretionExpense"/>
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    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditNextRolling12Months_019f7115-c671-7a00-87c9-5192666f854f_terseLabel_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditNextRolling12Months" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026-2027</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditNextRolling12Months_label_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditNextRolling12Months" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, Next Rolling 12 Months</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditNextRolling12Months_documentation_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditNextRolling12Months" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, Next Rolling 12 Months</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditNextRolling12Months" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CommitmentToSellRenewableEnergyCreditNextRolling12Months"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditNextRolling12Months" xlink:to="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditNextRolling12Months" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsForAdvanceToAffiliate_019f7115-c671-77ba-9ff8-edc81c19ffe7_terseLabel_en-US" xlink:label="lab_us-gaap_PaymentsForAdvanceToAffiliate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Payments for advance to affiliate</link:label>
    <link:label id="lab_us-gaap_PaymentsForAdvanceToAffiliate_label_en-US" xlink:label="lab_us-gaap_PaymentsForAdvanceToAffiliate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments for Advance to Affiliate</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForAdvanceToAffiliate" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForAdvanceToAffiliate"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsForAdvanceToAffiliate" xlink:to="lab_us-gaap_PaymentsForAdvanceToAffiliate" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueRecognitionPolicyTextBlock_019f7115-c555-7b14-9ff1-41f74fe5fe54_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRecognitionPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenue Recognition</link:label>
    <link:label id="lab_us-gaap_RevenueRecognitionPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_RevenueRecognitionPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRecognitionPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRecognitionPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRecognitionPolicyTextBlock" xlink:to="lab_us-gaap_RevenueRecognitionPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ProceedsFromFailedSaleLeasebackTransactionInvestingActivity_019f7115-c6fc-78ce-9743-9025e1fa9a54_terseLabel_en-US" xlink:label="lab_cik0001563922_ProceedsFromFailedSaleLeasebackTransactionInvestingActivity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from failed sale-leaseback</link:label>
    <link:label id="lab_cik0001563922_ProceedsFromFailedSaleLeasebackTransactionInvestingActivity_label_en-US" xlink:label="lab_cik0001563922_ProceedsFromFailedSaleLeasebackTransactionInvestingActivity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds From Failed Sale Leaseback Transaction, Investing Activity</link:label>
    <link:label id="lab_cik0001563922_ProceedsFromFailedSaleLeasebackTransactionInvestingActivity_documentation_en-US" xlink:label="lab_cik0001563922_ProceedsFromFailedSaleLeasebackTransactionInvestingActivity" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Proceeds From Failed Sale Leaseback Transaction, Investing Activity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ProceedsFromFailedSaleLeasebackTransactionInvestingActivity" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ProceedsFromFailedSaleLeasebackTransactionInvestingActivity"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ProceedsFromFailedSaleLeasebackTransactionInvestingActivity" xlink:to="lab_cik0001563922_ProceedsFromFailedSaleLeasebackTransactionInvestingActivity" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock_019f7115-c5e8-7378-8a14-8e94b55de36b_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Depreciation</link:label>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock_019f7115-c5e8-74bb-81dc-d35f5139c09d_verboseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Amortization Expense</link:label>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets Amortization Expense [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PreferredStockValue_019f7115-c555-757b-b3e1-0a65676833d6_verboseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockValue" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Preferred shares, par value, $0.001 per share, 50,000 authorized; none issued and outstanding</link:label>
    <link:label id="lab_us-gaap_PreferredStockValue_label_en-US" xlink:label="lab_us-gaap_PreferredStockValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred Stock, Value, Issued</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockValue" xlink:to="lab_us-gaap_PreferredStockValue" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DistributionReinvestmentPlanMember_019f7115-c5e8-7648-816e-e89d3f130c41_terseLabel_en-US" xlink:label="lab_cik0001563922_DistributionReinvestmentPlanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distribution Reinvestment Plan</link:label>
    <link:label id="lab_cik0001563922_DistributionReinvestmentPlanMember_label_en-US" xlink:label="lab_cik0001563922_DistributionReinvestmentPlanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distribution Reinvestment Plan [Member]</link:label>
    <link:label id="lab_cik0001563922_DistributionReinvestmentPlanMember_documentation_en-US" xlink:label="lab_cik0001563922_DistributionReinvestmentPlanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">It refers to the distribuion reinvestment plan type.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DistributionReinvestmentPlanMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DistributionReinvestmentPlanMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DistributionReinvestmentPlanMember" xlink:to="lab_cik0001563922_DistributionReinvestmentPlanMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_TaxCreditCarryforwardIndefinitelyMember_019f7115-c555-7a16-a94e-e9a5fd3a1906_terseLabel_en-US" xlink:label="lab_cik0001563922_TaxCreditCarryforwardIndefinitelyMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tax Credit Carryforward Indefinitely</link:label>
    <link:label id="lab_cik0001563922_TaxCreditCarryforwardIndefinitelyMember_label_en-US" xlink:label="lab_cik0001563922_TaxCreditCarryforwardIndefinitelyMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Tax Credit Carryforward Indefinitely [Member]</link:label>
    <link:label id="lab_cik0001563922_TaxCreditCarryforwardIndefinitelyMember_documentation_en-US" xlink:label="lab_cik0001563922_TaxCreditCarryforwardIndefinitelyMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tax Credit Carryforward Indefinitely</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TaxCreditCarryforwardIndefinitelyMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TaxCreditCarryforwardIndefinitelyMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_TaxCreditCarryforwardIndefinitelyMember" xlink:to="lab_cik0001563922_TaxCreditCarryforwardIndefinitelyMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet_019f7115-c5e8-74ee-b702-a6f457942ea1_terseLabel_en-US" xlink:label="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Carrying value</link:label>
    <link:label id="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet_label_en-US" xlink:label="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant, and Equipment, Lessor Asset under Operating Lease, after Accumulated Depreciation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet" xlink:to="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AuroraSolarHoldingsLLCMember_019f7115-c671-7cdc-928b-22fd845cfeb6_terseLabel_en-US" xlink:label="lab_cik0001563922_AuroraSolarHoldingsLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Aurora</link:label>
    <link:label id="lab_cik0001563922_AuroraSolarHoldingsLLCMember_label_en-US" xlink:label="lab_cik0001563922_AuroraSolarHoldingsLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Aurora Solar Holdings, LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_AuroraSolarHoldingsLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_AuroraSolarHoldingsLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Aurora Solar Holdings, LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AuroraSolarHoldingsLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AuroraSolarHoldingsLLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_AuroraSolarHoldingsLLCMember" xlink:to="lab_cik0001563922_AuroraSolarHoldingsLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RelatedPartyOfGCMMember_019f7115-c671-72ca-baaa-bb6cc3544093_terseLabel_en-US" xlink:label="lab_cik0001563922_RelatedPartyOfGCMMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Related Party of GCM</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyOfGCMMember_label_en-US" xlink:label="lab_cik0001563922_RelatedPartyOfGCMMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party of GCM [Member]</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyOfGCMMember_documentation_en-US" xlink:label="lab_cik0001563922_RelatedPartyOfGCMMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related Party of GCM</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RelatedPartyOfGCMMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RelatedPartyOfGCMMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RelatedPartyOfGCMMember" xlink:to="lab_cik0001563922_RelatedPartyOfGCMMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_019f7115-c671-7464-93b6-3501f1fb334e_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Deferred Tax Assets (Liabilities)</link:label>
    <link:label id="lab_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Deferred Tax Assets and Liabilities [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AmortizationOfDerivativeInstruments_019f7115-c671-713a-b89c-dde478a17b16_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_AmortizationOfDerivativeInstruments" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Amortization of interest rate swap contracts</link:label>
    <link:label id="lab_cik0001563922_AmortizationOfDerivativeInstruments_label_en-US" xlink:label="lab_cik0001563922_AmortizationOfDerivativeInstruments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amortization Of Derivative Instruments</link:label>
    <link:label id="lab_cik0001563922_AmortizationOfDerivativeInstruments_documentation_en-US" xlink:label="lab_cik0001563922_AmortizationOfDerivativeInstruments" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amortization Of Derivative Instruments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AmortizationOfDerivativeInstruments" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AmortizationOfDerivativeInstruments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_AmortizationOfDerivativeInstruments" xlink:to="lab_cik0001563922_AmortizationOfDerivativeInstruments" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommonStockValue_019f7115-c5e8-71d7-beaf-c9563ed9c953_verboseLabel_en-US" xlink:label="lab_us-gaap_CommonStockValue" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Common shares, par value, $0.001 per share, 350,000 authorized, 199,331 and 199,379 issued and outstanding as of 2026 and 2025, respectively</link:label>
    <link:label id="lab_us-gaap_CommonStockValue_label_en-US" xlink:label="lab_us-gaap_CommonStockValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock, Value, Issued</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockValue" xlink:to="lab_us-gaap_CommonStockValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseRightOfUseAsset_019f7115-c671-7dc6-8e26-04e7c284ce92_totalLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseRightOfUseAsset" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Property, plant and equipment, net</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseRightOfUseAsset_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseRightOfUseAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Right-of-Use Asset, after Accumulated Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAsset"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseRightOfUseAsset" xlink:to="lab_us-gaap_FinanceLeaseRightOfUseAsset" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019f7115-c6fc-7361-ade0-b6e2966af603_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table]</link:label>
    <link:label id="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_label_en-US" xlink:label="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:to="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommitmentsAndContingencies_019f7115-c671-7ef5-9780-111f5b546a7c_verboseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingencies" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Commitments and contingencies (Note 11. Commitments and Contingencies)</link:label>
    <link:label id="lab_us-gaap_CommitmentsAndContingencies_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingencies" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitments and Contingencies</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingencies" xlink:to="lab_us-gaap_CommitmentsAndContingencies" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFive_019f7115-c671-7845-b624-a87fa9adbd3f_terseLabel_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2030-2031</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFive_label_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, Rolling Year Five</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFive_documentation_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFive" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, Rolling Year Five</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFive" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFive"/>
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    <link:label id="lab_cik0001563922_CashSettledRestrictedStockUnitsMember_019f7115-c6fc-7a40-ab8e-8b60bfa0ab02_terseLabel_en-US" xlink:label="lab_cik0001563922_CashSettledRestrictedStockUnitsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash-settled restricted stock units</link:label>
    <link:label id="lab_cik0001563922_CashSettledRestrictedStockUnitsMember_label_en-US" xlink:label="lab_cik0001563922_CashSettledRestrictedStockUnitsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash-Settled Restricted Stock Units [Member]</link:label>
    <link:label id="lab_cik0001563922_CashSettledRestrictedStockUnitsMember_documentation_en-US" xlink:label="lab_cik0001563922_CashSettledRestrictedStockUnitsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cash-Settled Restricted Stock Units</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CashSettledRestrictedStockUnitsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CashSettledRestrictedStockUnitsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CashSettledRestrictedStockUnitsMember" xlink:to="lab_cik0001563922_CashSettledRestrictedStockUnitsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_VariableInterestEntityNameAxis_019f7115-c6fc-79bc-b829-4db781b08e2b_terseLabel_en-US" xlink:label="lab_cik0001563922_VariableInterestEntityNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Name [Axis]</link:label>
    <link:label id="lab_cik0001563922_VariableInterestEntityNameAxis_label_en-US" xlink:label="lab_cik0001563922_VariableInterestEntityNameAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Name [Axis]</link:label>
    <link:label id="lab_cik0001563922_VariableInterestEntityNameAxis_documentation_en-US" xlink:label="lab_cik0001563922_VariableInterestEntityNameAxis" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Name</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_VariableInterestEntityNameAxis" xlink:href="cik0001563922-20260810.xsd#cik0001563922_VariableInterestEntityNameAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_VariableInterestEntityNameAxis" xlink:to="lab_cik0001563922_VariableInterestEntityNameAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessAcquisitionAxis_019f7115-c6fc-75e2-9c37-5a705306cc70_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Business Combination [Axis]</link:label>
    <link:label id="lab_us-gaap_BusinessAcquisitionAxis_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Combination [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="lab_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019f7115-c555-7e37-97f1-1e43fe29e179_totalLabel_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Comprehensive loss</link:label>
    <link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:to="lab_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LoansPayableMember_019f7115-c6fc-78db-b110-a99bb8dffc48_terseLabel_en-US" xlink:label="lab_us-gaap_LoansPayableMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Loans Payable</link:label>
    <link:label id="lab_us-gaap_LoansPayableMember_label_en-US" xlink:label="lab_us-gaap_LoansPayableMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loans Payable [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansPayableMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansPayableMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LoansPayableMember" xlink:to="lab_us-gaap_LoansPayableMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NoncontrollingInterestMember_019f7115-c76d-76f4-ab91-0e23e0040301_verboseLabel_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Noncontrolling interests</link:label>
    <link:label id="lab_us-gaap_NoncontrollingInterestMember_019f7115-c76d-78e4-b43c-d4d7032beee0_terseLabel_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Noncontrolling interests</link:label>
    <link:label id="lab_us-gaap_NoncontrollingInterestMember_label_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncontrollingInterestMember" xlink:to="lab_us-gaap_NoncontrollingInterestMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationFeePayableTerm_019f7115-c671-73ab-bc5a-eb05b4b788ae_terseLabel_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationFeePayableTerm" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Liquidation performance participation fee payable, term (in days)</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationFeePayableTerm_label_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationFeePayableTerm" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Liquidation Performance Participation Fee Payable, Term</link:label>
    <link:label id="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationFeePayableTerm_documentation_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationFeePayableTerm" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Liquidation Performance Participation Fee Payable, Term</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationFeePayableTerm" xlink:href="cik0001563922-20260810.xsd#cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationFeePayableTerm"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationFeePayableTerm" xlink:to="lab_cik0001563922_RelatedPartyTransactionLiquidationPerformanceParticipationFeePayableTerm" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PaymentsToLoansMadeToOtherParties_019f7115-c6fc-7bdc-862f-3585b7ccce38_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_PaymentsToLoansMadeToOtherParties" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Loans made to other parties</link:label>
    <link:label id="lab_cik0001563922_PaymentsToLoansMadeToOtherParties_label_en-US" xlink:label="lab_cik0001563922_PaymentsToLoansMadeToOtherParties" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments To Loans Made To Other Parties</link:label>
    <link:label id="lab_cik0001563922_PaymentsToLoansMadeToOtherParties_documentation_en-US" xlink:label="lab_cik0001563922_PaymentsToLoansMadeToOtherParties" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Payments To Loans Made To Other Parties</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PaymentsToLoansMadeToOtherParties" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PaymentsToLoansMadeToOtherParties"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PaymentsToLoansMadeToOtherParties" xlink:to="lab_cik0001563922_PaymentsToLoansMadeToOtherParties" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EquityMethodInvestmentsPolicy_019f7115-c671-7cab-8cb1-6ba3d87f9261_terseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentsPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Equity Method Investments</link:label>
    <link:label id="lab_us-gaap_EquityMethodInvestmentsPolicy_label_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Method Investments [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentsPolicy"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityMethodInvestmentsPolicy" xlink:to="lab_us-gaap_EquityMethodInvestmentsPolicy" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense_019f7115-c5e8-7ebc-bfa0-4024b72e3cab_negatedLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Noncontrolling interest</link:label>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense_label_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense" xlink:to="lab_us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ValuationAllowanceLineItems_019f7115-c671-7403-9a2c-883649ca5989_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowanceLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Valuation Allowance [Line Items]</link:label>
    <link:label id="lab_us-gaap_ValuationAllowanceLineItems_label_en-US" xlink:label="lab_us-gaap_ValuationAllowanceLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Valuation Allowance [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationAllowanceLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ValuationAllowanceLineItems" xlink:to="lab_us-gaap_ValuationAllowanceLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EquityMethodInvestmentOwnershipPercentage_019f7115-c76d-7b58-8280-1794c7312bbc_terseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Equity method ownership percentage</link:label>
    <link:label id="lab_us-gaap_EquityMethodInvestmentOwnershipPercentage_label_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Method Investment, Ownership Percentage</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:to="lab_us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MinorityInterestTable_019f7115-c671-78ce-be8d-51478a7203c0_terseLabel_en-US" xlink:label="lab_us-gaap_MinorityInterestTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest [Table]</link:label>
    <link:label id="lab_us-gaap_MinorityInterestTable_label_en-US" xlink:label="lab_us-gaap_MinorityInterestTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MinorityInterestTable" xlink:to="lab_us-gaap_MinorityInterestTable" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ProductionCapacityOperational_019f7115-c554-7d35-9838-08a657f05e2a_terseLabel_en-US" xlink:label="lab_cik0001563922_ProductionCapacityOperational" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Production capacity, operational</link:label>
    <link:label id="lab_cik0001563922_ProductionCapacityOperational_label_en-US" xlink:label="lab_cik0001563922_ProductionCapacityOperational" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Production Capacity, Operational</link:label>
    <link:label id="lab_cik0001563922_ProductionCapacityOperational_documentation_en-US" xlink:label="lab_cik0001563922_ProductionCapacityOperational" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Production Capacity, Operational</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ProductionCapacityOperational" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ProductionCapacityOperational"/>
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    <link:label id="lab_us-gaap_ConcentrationRiskLineItems_019f7115-c6fc-7bbe-9650-afba4d3bd94c_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Concentration Risk [Line Items]</link:label>
    <link:label id="lab_us-gaap_ConcentrationRiskLineItems_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="lab_us-gaap_ConcentrationRiskLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_LetterOfCreditCommitmentMember_019f7115-c5e8-7cd8-bc5b-162737a115f2_terseLabel_en-US" xlink:label="lab_cik0001563922_LetterOfCreditCommitmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Letter of Credit Commitment</link:label>
    <link:label id="lab_cik0001563922_LetterOfCreditCommitmentMember_label_en-US" xlink:label="lab_cik0001563922_LetterOfCreditCommitmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Letter of Credit Commitment [Member]</link:label>
    <link:label id="lab_cik0001563922_LetterOfCreditCommitmentMember_documentation_en-US" xlink:label="lab_cik0001563922_LetterOfCreditCommitmentMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Letter of Credit Commitment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_LetterOfCreditCommitmentMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_LetterOfCreditCommitmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_LetterOfCreditCommitmentMember" xlink:to="lab_cik0001563922_LetterOfCreditCommitmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_EarnoutPeriodDomain_019f7115-c5e8-7989-b82a-561cf007a186_terseLabel_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earnout Period [Domain]</link:label>
    <link:label id="lab_cik0001563922_EarnoutPeriodDomain_label_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Earnout Period [Domain]</link:label>
    <link:label id="lab_cik0001563922_EarnoutPeriodDomain_documentation_en-US" xlink:label="lab_cik0001563922_EarnoutPeriodDomain" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Earnout Period [Domain]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_EarnoutPeriodDomain" xlink:to="lab_cik0001563922_EarnoutPeriodDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionTransactionCosts_019f7115-c6fc-7457-a32a-383057cb699d_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionTransactionCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Transaction costs</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionTransactionCosts_label_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionTransactionCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Transaction Costs</link:label>
    <link:label id="lab_cik0001563922_SaleLeasebackTransactionTransactionCosts_documentation_en-US" xlink:label="lab_cik0001563922_SaleLeasebackTransactionTransactionCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Leaseback Transaction, Transaction Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleLeasebackTransactionTransactionCosts" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleLeasebackTransactionTransactionCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleLeasebackTransactionTransactionCosts" xlink:to="lab_cik0001563922_SaleLeasebackTransactionTransactionCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DeferredTaxLiabilitiesInvestmentInSubsidiaries_019f7115-c5e8-7c59-b5df-58f60e097fe2_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_DeferredTaxLiabilitiesInvestmentInSubsidiaries" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Investments in flow-through entities taxed as partnerships</link:label>
    <link:label id="lab_cik0001563922_DeferredTaxLiabilitiesInvestmentInSubsidiaries_label_en-US" xlink:label="lab_cik0001563922_DeferredTaxLiabilitiesInvestmentInSubsidiaries" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Tax Liabilities, Investment In Subsidiaries</link:label>
    <link:label id="lab_cik0001563922_DeferredTaxLiabilitiesInvestmentInSubsidiaries_documentation_en-US" xlink:label="lab_cik0001563922_DeferredTaxLiabilitiesInvestmentInSubsidiaries" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Deferred Tax Liabilities, Investment In Subsidiaries</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DeferredTaxLiabilitiesInvestmentInSubsidiaries" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DeferredTaxLiabilitiesInvestmentInSubsidiaries"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DeferredTaxLiabilitiesInvestmentInSubsidiaries" xlink:to="lab_cik0001563922_DeferredTaxLiabilitiesInvestmentInSubsidiaries" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerAbstract_label_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue from Contract with Customer [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="lab_us-gaap_RevenueFromContractWithCustomerAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PurchaseObligationDepositPercentage_019f7115-c6fc-7eec-b606-3b3f29518c44_terseLabel_en-US" xlink:label="lab_cik0001563922_PurchaseObligationDepositPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Percentage of deposits</link:label>
    <link:label id="lab_cik0001563922_PurchaseObligationDepositPercentage_label_en-US" xlink:label="lab_cik0001563922_PurchaseObligationDepositPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Purchase Obligation, Deposit, Percentage</link:label>
    <link:label id="lab_cik0001563922_PurchaseObligationDepositPercentage_documentation_en-US" xlink:label="lab_cik0001563922_PurchaseObligationDepositPercentage" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Purchase Obligation, Deposit, Percentage</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PurchaseObligationDepositPercentage" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PurchaseObligationDepositPercentage"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PurchaseObligationDepositPercentage" xlink:to="lab_cik0001563922_PurchaseObligationDepositPercentage" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_HedgingDesignationAxis_019f7115-c5e8-7662-b2cb-8818068a1789_terseLabel_en-US" xlink:label="lab_us-gaap_HedgingDesignationAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Hedging Designation [Axis]</link:label>
    <link:label id="lab_us-gaap_HedgingDesignationAxis_label_en-US" xlink:label="lab_us-gaap_HedgingDesignationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Hedging Designation [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_HedgingDesignationAxis" xlink:to="lab_us-gaap_HedgingDesignationAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherInterestAndDividendIncome_019f7115-c555-7224-97d4-d31bb47cc38b_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_OtherInterestAndDividendIncome" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Interest income on non-bank deposits</link:label>
    <link:label id="lab_us-gaap_OtherInterestAndDividendIncome_label_en-US" xlink:label="lab_us-gaap_OtherInterestAndDividendIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Interest and Dividend Income</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherInterestAndDividendIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherInterestAndDividendIncome"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherInterestAndDividendIncome" xlink:to="lab_us-gaap_OtherInterestAndDividendIncome" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_StatementScenarioAxis_019f7115-c5e8-7777-adf4-d4928244d63e_terseLabel_en-US" xlink:label="lab_srt_StatementScenarioAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Scenario [Axis]</link:label>
    <link:label id="lab_srt_StatementScenarioAxis_label_en-US" xlink:label="lab_srt_StatementScenarioAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Scenario [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementScenarioAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_StatementScenarioAxis" xlink:to="lab_srt_StatementScenarioAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_TaxCreditBenefitsRealized_019f7115-c76d-7516-9a3b-7bb0589d7497_terseLabel_en-US" xlink:label="lab_cik0001563922_TaxCreditBenefitsRealized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tax credit benefits realized</link:label>
    <link:label id="lab_cik0001563922_TaxCreditBenefitsRealized_label_en-US" xlink:label="lab_cik0001563922_TaxCreditBenefitsRealized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Tax Credit Benefits Realized</link:label>
    <link:label id="lab_cik0001563922_TaxCreditBenefitsRealized_documentation_en-US" xlink:label="lab_cik0001563922_TaxCreditBenefitsRealized" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tax Credit Benefits Realized</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TaxCreditBenefitsRealized" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TaxCreditBenefitsRealized"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_TaxCreditBenefitsRealized" xlink:to="lab_cik0001563922_TaxCreditBenefitsRealized" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAccumulatedAmortization_019f7115-c671-7a4b-94e2-08b897ee4595_terseLabel_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accumulated amortization</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAccumulatedAmortization_label_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities, Accumulated Amortization</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAccumulatedAmortization_documentation_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities, Accumulated Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAccumulatedAmortization" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAccumulatedAmortization"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAccumulatedAmortization" xlink:to="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesAccumulatedAmortization" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets_019f7115-c671-74af-8851-b5e7bb8100e4_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other noncurrent assets</link:label>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets_label_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets" xlink:to="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeContractTypeDomain_019f7115-c554-70e9-b394-1bbbb94d33c7_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative Contract [Domain]</link:label>
    <link:label id="lab_us-gaap_DerivativeContractTypeDomain_label_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Contract [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeContractTypeDomain" xlink:to="lab_us-gaap_DerivativeContractTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NoncontrollingInterestDecreaseFromReclassificationOfPromissoryNote_019f7115-c554-74ff-927f-7f78631c46bb_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestDecreaseFromReclassificationOfPromissoryNote" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Other noncontrolling interest activity</link:label>
    <link:label id="lab_cik0001563922_NoncontrollingInterestDecreaseFromReclassificationOfPromissoryNote_label_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestDecreaseFromReclassificationOfPromissoryNote" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Decrease From Reclassification Of Promissory Note</link:label>
    <link:label id="lab_cik0001563922_NoncontrollingInterestDecreaseFromReclassificationOfPromissoryNote_documentation_en-US" xlink:label="lab_cik0001563922_NoncontrollingInterestDecreaseFromReclassificationOfPromissoryNote" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest, Decrease From Reclassification Of Promissory Note</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NoncontrollingInterestDecreaseFromReclassificationOfPromissoryNote" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NoncontrollingInterestDecreaseFromReclassificationOfPromissoryNote"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NoncontrollingInterestDecreaseFromReclassificationOfPromissoryNote" xlink:to="lab_cik0001563922_NoncontrollingInterestDecreaseFromReclassificationOfPromissoryNote" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongtermDebtTypeDomain_019f7115-c6fc-75d3-af45-1e87590ebeb8_terseLabel_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-term Debt, Type [Domain]</link:label>
    <link:label id="lab_us-gaap_LongtermDebtTypeDomain_label_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Type [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongtermDebtTypeDomain" xlink:to="lab_us-gaap_LongtermDebtTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueDisclosuresAbstract_019f7115-c554-701c-9d46-b95a8a3720f9_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueDisclosuresAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Disclosures [Abstract]</link:label>
    <link:label id="lab_us-gaap_FairValueDisclosuresAbstract_label_en-US" xlink:label="lab_us-gaap_FairValueDisclosuresAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Disclosures [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosuresAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosuresAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueDisclosuresAbstract" xlink:to="lab_us-gaap_FairValueDisclosuresAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019f7115-c671-7be7-9ed7-a12868f613ca_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Purchases of property, plant and equipment</link:label>
    <link:label id="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments to Acquire Property, Plant, and Equipment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_UnrealizedGainLossOnDerivatives_019f7115-c555-755f-b55e-904b622dfec2_negatedLabel_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnDerivatives" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Change in fair value of interest rate swaps, net</link:label>
    <link:label id="lab_us-gaap_UnrealizedGainLossOnDerivatives_019f7115-c555-74da-a6b6-de8193552fb8_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnDerivatives" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Change in fair value of interest rate swaps, net</link:label>
    <link:label id="lab_us-gaap_UnrealizedGainLossOnDerivatives_label_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnDerivatives" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Unrealized Gain (Loss) on Derivatives</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnDerivatives" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrealizedGainLossOnDerivatives"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UnrealizedGainLossOnDerivatives" xlink:to="lab_us-gaap_UnrealizedGainLossOnDerivatives" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherAssetImpairmentCharges_019f7115-c671-706a-8b3c-c2043261b5df_terseLabel_en-US" xlink:label="lab_us-gaap_OtherAssetImpairmentCharges" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Impairment of long-lived assets, net and termination costs</link:label>
    <link:label id="lab_us-gaap_OtherAssetImpairmentCharges_label_en-US" xlink:label="lab_us-gaap_OtherAssetImpairmentCharges" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Asset Impairment Charges</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetImpairmentCharges" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetImpairmentCharges"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherAssetImpairmentCharges" xlink:to="lab_us-gaap_OtherAssetImpairmentCharges" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ClassISharesMember_019f7115-c671-7b14-b808-cdfe5cde5143_terseLabel_en-US" xlink:label="lab_cik0001563922_ClassISharesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class I</link:label>
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    <link:label id="lab_cik0001563922_ClassISharesMember_documentation_en-US" xlink:label="lab_cik0001563922_ClassISharesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Class I Shares</link:label>
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    <link:label id="lab_cik0001563922_DeferredCompensationLiabilityPerAnnumFeePercent_019f7115-c6fc-7681-96fa-9ad46970bfa0_terseLabel_en-US" xlink:label="lab_cik0001563922_DeferredCompensationLiabilityPerAnnumFeePercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred sales commission, per annum fee percent</link:label>
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    <link:label id="lab_cik0001563922_CommitmentToFundConstructionOfFacilitiesMember_label_en-US" xlink:label="lab_cik0001563922_CommitmentToFundConstructionOfFacilitiesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitment To Fund Construction Of Facilities [Member]</link:label>
    <link:label id="lab_cik0001563922_CommitmentToFundConstructionOfFacilitiesMember_documentation_en-US" xlink:label="lab_cik0001563922_CommitmentToFundConstructionOfFacilitiesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Commitment To Fund Construction Of Facilities</link:label>
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    <link:label id="lab_us-gaap_ConcentrationRiskBenchmarkDomain_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk Benchmark [Domain]</link:label>
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    <link:label id="lab_cik0001563922_StateNetOperatingLossCarryforwardMember_documentation_en-US" xlink:label="lab_cik0001563922_StateNetOperatingLossCarryforwardMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">State Net Operating Loss Carryforward</link:label>
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    <link:label id="lab_us-gaap_CapitalizedContractCostAmortization_019f7115-c554-7d51-96a3-b595664292d7_terseLabel_en-US" xlink:label="lab_us-gaap_CapitalizedContractCostAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Capitalized contract cost, amortization</link:label>
    <link:label id="lab_us-gaap_CapitalizedContractCostAmortization_label_en-US" xlink:label="lab_us-gaap_CapitalizedContractCostAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Capitalized Contract Cost, Amortization</link:label>
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    <link:label id="lab_us-gaap_FairValueMeasuredOnRecurringBasisGainLossIncludedInEarningsAbstract_label_en-US" xlink:label="lab_us-gaap_FairValueMeasuredOnRecurringBasisGainLossIncludedInEarningsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasuredOnRecurringBasisGainLossIncludedInEarningsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasuredOnRecurringBasisGainLossIncludedInEarningsAbstract"/>
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    <link:label id="lab_us-gaap_EarningsPerShareAbstract_019f7115-c671-7ade-a67f-2afa253591fb_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earnings per share</link:label>
    <link:label id="lab_us-gaap_EarningsPerShareAbstract_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Earnings Per Share [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareAbstract"/>
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    <link:label id="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioTwoMember_documentation_en-US" xlink:label="lab_cik0001563922_RelatedPartyTransactionFeeArrangementScenarioTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related Party Transaction, Fee Arrangement, Scenario Two</link:label>
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    <link:label id="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReturnOfCapital_documentation_en-US" xlink:label="lab_cik0001563922_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReturnOfCapital" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Return Of Capital</link:label>
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    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFour_019f7115-c671-7cb8-bfb8-1a7111698b30_verboseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFour" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">2029-2030</link:label>
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    <link:label id="lab_cik0001563922_FinanceLeaseCostAbstract_019f7115-c6fc-7937-a0e7-5f8fb3564b07_terseLabel_en-US" xlink:label="lab_cik0001563922_FinanceLeaseCostAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Finance lease cost</link:label>
    <link:label id="lab_cik0001563922_FinanceLeaseCostAbstract_label_en-US" xlink:label="lab_cik0001563922_FinanceLeaseCostAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Cost [Abstract]</link:label>
    <link:label id="lab_cik0001563922_FinanceLeaseCostAbstract_documentation_en-US" xlink:label="lab_cik0001563922_FinanceLeaseCostAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Finance Lease, Cost</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FinanceLeaseCostAbstract" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FinanceLeaseCostAbstract"/>
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    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassDomain_019f7115-c76d-7841-9f68-4dc51abd0bbd_terseLabel_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesByMajorClassDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities By Major Class [Domain]</link:label>
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    <link:label id="lab_cik0001563922_ReclassificationsOfTemporaryEquityToPermanent_documentation_en-US" xlink:label="lab_cik0001563922_ReclassificationsOfTemporaryEquityToPermanent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Reclassifications Of Temporary Equity To Permanent</link:label>
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    <link:label id="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_019f7115-c555-7393-a37c-a4737aa8d9ff_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounts Payable and Accrued Liabilities</link:label>
    <link:label id="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_label_en-US" xlink:label="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts Payable and Accrued Liabilities [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesMember"/>
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    <link:label id="lab_us-gaap_DebtInstrumentRepaidPrincipal_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentRepaidPrincipal" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Repaid, Principal</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
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    <link:label id="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesMember_019f7115-c76d-7194-b8f3-39b89dc8130b_terseLabel_en-US" xlink:label="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Additional paid-in capital - redeemable common shares</link:label>
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    <link:label id="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesMember_documentation_en-US" xlink:label="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Additional Paid-In-Capital, Redeemable Common Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesMember"/>
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    <link:label id="lab_cik0001563922_FederalNetOperatingLossCarryforwardsMember_label_en-US" xlink:label="lab_cik0001563922_FederalNetOperatingLossCarryforwardsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Federal Net Operating Loss Carryforwards [Member]</link:label>
    <link:label id="lab_cik0001563922_FederalNetOperatingLossCarryforwardsMember_documentation_en-US" xlink:label="lab_cik0001563922_FederalNetOperatingLossCarryforwardsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Federal Net Operating Loss Carryforwards</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FederalNetOperatingLossCarryforwardsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FederalNetOperatingLossCarryforwardsMember"/>
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    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsTransactionCosts_019f7115-c555-74bf-95ff-c9a001c0e9d2_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsTransactionCosts" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Less: transaction costs</link:label>
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    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsTransactionCosts_documentation_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsTransactionCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operations, Transaction Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsTransactionCosts" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DisposalGroupIncludingDiscontinuedOperationsTransactionCosts"/>
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    <link:label id="lab_cik0001563922_CreditAgreementMember_019f7115-c76d-75eb-9e81-c7b1bb57c49d_terseLabel_en-US" xlink:label="lab_cik0001563922_CreditAgreementMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Credit Agreement</link:label>
    <link:label id="lab_cik0001563922_CreditAgreementMember_label_en-US" xlink:label="lab_cik0001563922_CreditAgreementMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Credit Agreement [Member]</link:label>
    <link:label id="lab_cik0001563922_CreditAgreementMember_documentation_en-US" xlink:label="lab_cik0001563922_CreditAgreementMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Credit Agreement</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CreditAgreementMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CreditAgreementMember"/>
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    <link:label id="lab_cik0001563922_AssetsAndLiabilitiesLesseeTableTextBlock_019f7115-c5e8-7c09-b548-4cf637b56118_terseLabel_en-US" xlink:label="lab_cik0001563922_AssetsAndLiabilitiesLesseeTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Supplemental Balance Sheet Information</link:label>
    <link:label id="lab_cik0001563922_AssetsAndLiabilitiesLesseeTableTextBlock_label_en-US" xlink:label="lab_cik0001563922_AssetsAndLiabilitiesLesseeTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Assets And Liabilities, Lessee [Table Text Block]</link:label>
    <link:label id="lab_cik0001563922_AssetsAndLiabilitiesLesseeTableTextBlock_documentation_en-US" xlink:label="lab_cik0001563922_AssetsAndLiabilitiesLesseeTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Assets And Liabilities, Lessee</link:label>
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    <link:label id="lab_us-gaap_FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerShareUnfundedCommittments_019f7115-c671-7a17-8bb6-bbd8cbcbecf9_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerShareUnfundedCommittments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unfunded commitments</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerShareUnfundedCommittments" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerShareUnfundedCommittments"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasuredOnRecurringBasisGainLossIncludedInEarningsTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasuredOnRecurringBasisGainLossIncludedInEarningsTable"/>
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    <link:label id="lab_us-gaap_DistributionMadeToLimitedLiabilityCompanyLLCMemberCashDistributionsDeclared_019f7115-c671-7a39-a661-858ef7ed0031_terseLabel_en-US" xlink:label="lab_us-gaap_DistributionMadeToLimitedLiabilityCompanyLLCMemberCashDistributionsDeclared" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distribution received</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsNetAssetsAndNoncontrollingInterest" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DisposalGroupIncludingDiscontinuedOperationsNetAssetsAndNoncontrollingInterest"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsNetAssetsAndNoncontrollingInterest" xlink:to="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsNetAssetsAndNoncontrollingInterest" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_019f7115-c671-796c-a35c-04677a33ae00_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">State</link:label>
    <link:label id="lab_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred State and Local Income Tax Expense (Benefit)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:to="lab_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NonCashInvoluntaryConversion_019f7115-c6fc-764d-89cb-aabdefc9d183_terseLabel_en-US" xlink:label="lab_cik0001563922_NonCashInvoluntaryConversion" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Non-cash involuntary conversion</link:label>
    <link:label id="lab_cik0001563922_NonCashInvoluntaryConversion_label_en-US" xlink:label="lab_cik0001563922_NonCashInvoluntaryConversion" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Non Cash Involuntary Conversion</link:label>
    <link:label id="lab_cik0001563922_NonCashInvoluntaryConversion_documentation_en-US" xlink:label="lab_cik0001563922_NonCashInvoluntaryConversion" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Non Cash Involuntary Conversion</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NonCashInvoluntaryConversion" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NonCashInvoluntaryConversion"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NonCashInvoluntaryConversion" xlink:to="lab_cik0001563922_NonCashInvoluntaryConversion" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ProductionCapacity_019f7115-c555-7b7f-ad95-5ae72ae0d67e_totalLabel_en-US" xlink:label="lab_cik0001563922_ProductionCapacity" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Production capacity (in gigawatt)</link:label>
    <link:label id="lab_cik0001563922_ProductionCapacity_label_en-US" xlink:label="lab_cik0001563922_ProductionCapacity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Production Capacity</link:label>
    <link:label id="lab_cik0001563922_ProductionCapacity_documentation_en-US" xlink:label="lab_cik0001563922_ProductionCapacity" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Production Capacity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ProductionCapacity" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ProductionCapacity"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ProductionCapacity" xlink:to="lab_cik0001563922_ProductionCapacity" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetIncomeLoss_019f7115-c671-71cc-ab80-5397551404ef_totalLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net loss attributable to Greenbacker Renewable Energy Company LLC</link:label>
    <link:label id="lab_us-gaap_NetIncomeLoss_019f7115-c671-7b88-9fab-265346b767b8_verboseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Net loss attributable to Greenbacker Renewable Energy Company LLC</link:label>
    <link:label id="lab_us-gaap_NetIncomeLoss_label_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss) Attributable to Parent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetIncomeLoss" xlink:to="lab_us-gaap_NetIncomeLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SubsequentEventTable_019f7115-c76d-734e-982e-eb49c8d441be_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Event [Table]</link:label>
    <link:label id="lab_us-gaap_SubsequentEventTable_label_en-US" xlink:label="lab_us-gaap_SubsequentEventTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTable" xlink:to="lab_us-gaap_SubsequentEventTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesNoncurrentAbstract_019f7115-c671-70db-ae0a-cca357fd9d2e_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesNoncurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Noncurrent liabilities:</link:label>
    <link:label id="lab_us-gaap_LiabilitiesNoncurrentAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesNoncurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Liabilities, Noncurrent [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesNoncurrentAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="lab_us-gaap_LiabilitiesNoncurrentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding_019f7115-c6fc-7c19-a4be-252b1268cb46_periodStartLabel_en-US" xlink:label="lab_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Beginning balance (in shares)</link:label>
    <link:label id="lab_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding_019f7115-c6fc-73af-b434-de6d8136bb89_periodEndLabel_en-US" xlink:label="lab_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Ending balance (in shares)</link:label>
    <link:label id="lab_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding_label_en-US" xlink:label="lab_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock And Temporary Equity, Shares Outstanding</link:label>
    <link:label id="lab_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding_documentation_en-US" xlink:label="lab_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Common Stock And Temporary Equity, Shares Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding" xlink:to="lab_cik0001563922_CommonStockAndTemporaryEquitySharesOutstanding" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationRestrictedCashCurrent_019f7115-c554-7f1d-9833-741e7151ae86_terseLabel_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationRestrictedCashCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Restricted cash, current</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationRestrictedCashCurrent_label_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationRestrictedCashCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Restricted Cash, Current</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationRestrictedCashCurrent_documentation_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationRestrictedCashCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Restricted Cash, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationRestrictedCashCurrent" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DisposalGroupIncludingDiscontinuedOperationRestrictedCashCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationRestrictedCashCurrent" xlink:to="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationRestrictedCashCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_019f7115-c555-72c6-8ae8-c4a11eb95bda_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Effective Tax Rate Reconciliation</link:label>
    <link:label id="lab_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019f7115-c5e8-7e52-b81d-6aa21219da71_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Award vesting period (in years)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019f7115-c5e8-7761-bc32-61f2fa0e3467_totalLabel_en-US" xlink:label="lab_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total equity</link:label>
    <link:label id="lab_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019f7115-c5e8-7bb8-ad2b-23b7cd2a6fde_periodStartLabel_en-US" xlink:label="lab_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Total equity, beginning balance</link:label>
    <link:label id="lab_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019f7115-c5e8-746b-84b5-e302ccd87572_periodEndLabel_en-US" xlink:label="lab_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Total equity, ending balance</link:label>
    <link:label id="lab_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Limited Liability Company (LLC) Members' Equity, Including Portion Attributable to Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
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    <link:label id="lab_us-gaap_SegmentReportingInformationLineItems_019f7115-c554-7195-a562-788e70e26151_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentReportingInformationLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Segment Reporting Information [Line Items]</link:label>
    <link:label id="lab_us-gaap_SegmentReportingInformationLineItems_label_en-US" xlink:label="lab_us-gaap_SegmentReportingInformationLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segment Reporting Information [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems" xlink:to="lab_us-gaap_SegmentReportingInformationLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PreferredStockSharesAuthorized_019f7115-c554-759a-a59c-c86c1ae509bc_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Preferred shares, shares authorized (in shares)</link:label>
    <link:label id="lab_us-gaap_PreferredStockSharesAuthorized_label_en-US" xlink:label="lab_us-gaap_PreferredStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred Stock, Shares Authorized</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockSharesAuthorized" xlink:to="lab_us-gaap_PreferredStockSharesAuthorized" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsForRepurchaseOfCommonStock_019f7115-c671-7fd1-a913-b8e1b93c0bb4_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Repurchases of common shares</link:label>
    <link:label id="lab_us-gaap_PaymentsForRepurchaseOfCommonStock_label_en-US" xlink:label="lab_us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments for Repurchase of Common Stock</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
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    <link:label id="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription_019f7115-c671-7407-b5f4-cf71b0a7c543_verboseLabel_en-US" xlink:label="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Reclassifications</link:label>
    <link:label id="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription_label_en-US" xlink:label="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reclassification, Comparability Adjustment [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PriorPeriodReclassificationAdjustmentDescription"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:to="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionDeferredInvestmentTaxCreditGainCurrent_019f7115-c6fc-7c15-bb42-6c00609dae41_terseLabel_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionDeferredInvestmentTaxCreditGainCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">ITC gains, current</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionDeferredInvestmentTaxCreditGainCurrent_label_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionDeferredInvestmentTaxCreditGainCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Deferred Investment Tax Credit Gain, Current</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionDeferredInvestmentTaxCreditGainCurrent_documentation_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionDeferredInvestmentTaxCreditGainCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Deferred Investment Tax Credit Gain, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FailedSaleLeasebackTransactionDeferredInvestmentTaxCreditGainCurrent" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FailedSaleLeasebackTransactionDeferredInvestmentTaxCreditGainCurrent"/>
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    <link:label id="lab_us-gaap_ContractWithCustomerAssetNet_019f7115-c6fc-7c6c-b893-fa81ae31a88d_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contract assets</link:label>
    <link:label id="lab_us-gaap_ContractWithCustomerAssetNet_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract with Customer, Asset, after Allowance for Credit Loss</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetNet" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ContractWithCustomerAssetNet" xlink:to="lab_us-gaap_ContractWithCustomerAssetNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseTermOfContract_019f7115-c5e8-7848-8f1b-9ab9cad6cddb_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseTermOfContract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Lease term (in years)</link:label>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseTermOfContract_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseTermOfContract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Term of Contract</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseTermOfContract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseTermOfContract" xlink:to="lab_us-gaap_LesseeOperatingLeaseTermOfContract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PowerOfSolarAsset_019f7115-c5e8-78f9-9077-c62c461714af_terseLabel_en-US" xlink:label="lab_cik0001563922_PowerOfSolarAsset" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Solar asset power (in megawatt)</link:label>
    <link:label id="lab_cik0001563922_PowerOfSolarAsset_label_en-US" xlink:label="lab_cik0001563922_PowerOfSolarAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Power Of Solar Asset</link:label>
    <link:label id="lab_cik0001563922_PowerOfSolarAsset_documentation_en-US" xlink:label="lab_cik0001563922_PowerOfSolarAsset" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Power Of Solar Asset</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PowerOfSolarAsset" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PowerOfSolarAsset"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PowerOfSolarAsset" xlink:to="lab_cik0001563922_PowerOfSolarAsset" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MeasurementInputExpectedTermMember_019f7115-c671-7a99-8280-284eb1f385c0_terseLabel_en-US" xlink:label="lab_us-gaap_MeasurementInputExpectedTermMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Useful Life</link:label>
    <link:label id="lab_us-gaap_MeasurementInputExpectedTermMember_label_en-US" xlink:label="lab_us-gaap_MeasurementInputExpectedTermMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input, Expected Term [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputExpectedTermMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputExpectedTermMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MeasurementInputExpectedTermMember" xlink:to="lab_us-gaap_MeasurementInputExpectedTermMember" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_MajorCustomersAxis_019f7115-c6fc-7668-8263-61428add6f9f_terseLabel_en-US" xlink:label="lab_srt_MajorCustomersAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Customer [Axis]</link:label>
    <link:label id="lab_srt_MajorCustomersAxis_label_en-US" xlink:label="lab_srt_MajorCustomersAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Customer [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MajorCustomersAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_MajorCustomersAxis" xlink:to="lab_srt_MajorCustomersAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOutOfMarketContractsNet_019f7115-c554-7beb-aa9e-5b224a5a0cad_verboseLabel_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOutOfMarketContractsNet" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Out-of-market contracts, net</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOutOfMarketContractsNet_label_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOutOfMarketContractsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Out-Of-Market Contracts, Net</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOutOfMarketContractsNet_documentation_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOutOfMarketContractsNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Out-Of-Market Contracts, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOutOfMarketContractsNet" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DisposalGroupIncludingDiscontinuedOperationOutOfMarketContractsNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOutOfMarketContractsNet" xlink:to="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationOutOfMarketContractsNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingIncomeLoss_019f7115-c6fc-7625-af5f-ea3101dd0947_totalLabel_en-US" xlink:label="lab_us-gaap_OperatingIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Operating loss</link:label>
    <link:label id="lab_us-gaap_OperatingIncomeLoss_label_en-US" xlink:label="lab_us-gaap_OperatingIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Income (Loss)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingIncomeLoss" xlink:to="lab_us-gaap_OperatingIncomeLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LineOfCreditMember_019f7115-c671-7e2d-860e-374f64ba8ea5_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Line of Credit</link:label>
    <link:label id="lab_us-gaap_LineOfCreditMember_label_en-US" xlink:label="lab_us-gaap_LineOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditMember" xlink:to="lab_us-gaap_LineOfCreditMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RetainedEarningsAccumulatedDeficit_019f7115-c6fc-7273-bd8e-80bec62de0be_terseLabel_en-US" xlink:label="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accumulated deficit</link:label>
    <link:label id="lab_us-gaap_RetainedEarningsAccumulatedDeficit_label_en-US" xlink:label="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Retained Earnings (Accumulated Deficit)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearThree_019f7115-c6fc-7b9b-92b6-153feec88ded_terseLabel_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2028-2029</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearThree_label_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, Rolling Year Three</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearThree_documentation_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearThree" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, Rolling Year Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearThree" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearThree"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearThree" xlink:to="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearThree" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedUnitsVestedAndExpectedToVestTableTextBlock_019f7115-c555-74b8-acbf-5fd5a60bc46d_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedUnitsVestedAndExpectedToVestTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Assumptions and Related Information to Determine Grant Date Fair Value of Performance Restricted Stock Units</link:label>
    <link:label id="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedUnitsVestedAndExpectedToVestTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedUnitsVestedAndExpectedToVestTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangements by Share-Based Payment Award, Performance-Based Units, Vested and Expected to Vest [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedUnitsVestedAndExpectedToVestTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedUnitsVestedAndExpectedToVestTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedUnitsVestedAndExpectedToVestTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedUnitsVestedAndExpectedToVestTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsAndRenewableEnergyCreditsMember_019f7115-c671-77d9-a90b-6db7d1f60c53_terseLabel_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsAndRenewableEnergyCreditsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Favorable Contract amortization as a reduction to revenue</link:label>
    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsAndRenewableEnergyCreditsMember_label_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsAndRenewableEnergyCreditsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Power Purchase Agreements and Renewable Energy Credits [Member]</link:label>
    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsAndRenewableEnergyCreditsMember_documentation_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsAndRenewableEnergyCreditsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Power Purchase Agreements and Renewable Energy Credits</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PowerPurchaseAgreementsAndRenewableEnergyCreditsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PowerPurchaseAgreementsAndRenewableEnergyCreditsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PowerPurchaseAgreementsAndRenewableEnergyCreditsMember" xlink:to="lab_cik0001563922_PowerPurchaseAgreementsAndRenewableEnergyCreditsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementClassOfStockAxis_019f7115-c6fc-7f4e-8954-35f37f0af2ee_terseLabel_en-US" xlink:label="lab_us-gaap_StatementClassOfStockAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Stock [Axis]</link:label>
    <link:label id="lab_us-gaap_StatementClassOfStockAxis_label_en-US" xlink:label="lab_us-gaap_StatementClassOfStockAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Stock [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementClassOfStockAxis" xlink:to="lab_us-gaap_StatementClassOfStockAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVIncentiveFeesMember_019f7115-c671-7a99-a352-d342530fa4c0_terseLabel_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVIncentiveFeesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GDEV I incentive fees</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVIncentiveFeesMember_label_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVIncentiveFeesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities Fund I, LP ("GDEV") Incentive Fees [Member]</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVIncentiveFeesMember_documentation_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVIncentiveFeesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities Fund I, LP ("GDEV") Incentive Fees</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVIncentiveFeesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVIncentiveFeesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVIncentiveFeesMember" xlink:to="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundILPGDEVIncentiveFeesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNet_019f7115-c5e8-7f4a-944c-58cec6e9dfd7_negatedTotalLabel_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNet" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xml:lang="en-US">Net out-of-market contracts</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNet_label_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities, Net</link:label>
    <link:label id="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNet_documentation_en-US" xlink:label="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Out-of-Market Contracts, Intangible Liabilities, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNet" xlink:href="cik0001563922-20260810.xsd#cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNet" xlink:to="lab_cik0001563922_OutOfMarketContractsIntangibleLiabilitiesNet" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionTransactionCosts_019f7115-c6fc-7efe-bf4f-4a3989ad5548_terseLabel_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionTransactionCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Failed sale leaseback transaction, transaction costs</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionTransactionCosts_label_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionTransactionCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Transaction Costs</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionTransactionCosts_documentation_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionTransactionCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Transaction Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FailedSaleLeasebackTransactionTransactionCosts" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FailedSaleLeasebackTransactionTransactionCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FailedSaleLeasebackTransactionTransactionCosts" xlink:to="lab_cik0001563922_FailedSaleLeasebackTransactionTransactionCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SubsequentEventTypeDomain_019f7115-c5e8-731f-9d93-a2c3bfe2a04e_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Event Type [Domain]</link:label>
    <link:label id="lab_us-gaap_SubsequentEventTypeDomain_label_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event Type [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTypeDomain" xlink:to="lab_us-gaap_SubsequentEventTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesCommonClassEarnoutMember_019f7115-c671-75b7-8acf-e1a01f457906_terseLabel_en-US" xlink:label="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesCommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Additional Paid-In-Capital, Redeemable Common Shares, Common Class Earnout</link:label>
    <link:label id="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesCommonClassEarnoutMember_label_en-US" xlink:label="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesCommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Additional Paid-In-Capital, Redeemable Common Shares, Common Class Earnout [Member]</link:label>
    <link:label id="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesCommonClassEarnoutMember_documentation_en-US" xlink:label="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesCommonClassEarnoutMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Additional Paid-In-Capital, Redeemable Common Shares, Common Class Earnout</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesCommonClassEarnoutMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesCommonClassEarnoutMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesCommonClassEarnoutMember" xlink:to="lab_cik0001563922_AdditionalPaidInCapitalRedeemableCommonSharesCommonClassEarnoutMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpense_019f7115-c671-7afb-812e-7aeafafc9b32_totalLabel_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpense" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpense_label_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale And Leaseback Transaction, Interest Expense</link:label>
    <link:label id="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpense_documentation_en-US" xlink:label="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpense" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale And Leaseback Transaction, Interest Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleAndLeasebackTransactionInterestExpense" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleAndLeasebackTransactionInterestExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleAndLeasebackTransactionInterestExpense" xlink:to="lab_cik0001563922_SaleAndLeasebackTransactionInterestExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems_019f7115-c5e8-7448-8829-c2e5089b737f_terseLabel_en-US" xlink:label="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, Plant, and Equipment, Lessor Asset under Operating Lease [Line Items]</link:label>
    <link:label id="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems_label_en-US" xlink:label="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant, and Equipment, Lessor Asset under Operating Lease [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems" xlink:to="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_019f7115-c6fc-75fa-861b-7071d273e29f_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total current liabilities</link:label>
    <link:label id="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_label_en-US" xlink:label="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Liabilities, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:to="lab_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherNonoperatingIncomeExpense_019f7115-c671-7e44-adde-fb3e50ddd488_terseLabel_en-US" xlink:label="lab_us-gaap_OtherNonoperatingIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other income, net</link:label>
    <link:label id="lab_us-gaap_OtherNonoperatingIncomeExpense_019f7115-c671-75dc-9a87-1fa0d9b70a6c_verboseLabel_en-US" xlink:label="lab_us-gaap_OtherNonoperatingIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Other income, net</link:label>
    <link:label id="lab_us-gaap_OtherNonoperatingIncomeExpense_label_en-US" xlink:label="lab_us-gaap_OtherNonoperatingIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Nonoperating Income (Expense)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpense" xlink:to="lab_us-gaap_OtherNonoperatingIncomeExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementTable_019f7115-c6fc-7d52-b7f9-fed8bd6ca68b_terseLabel_en-US" xlink:label="lab_us-gaap_StatementTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement [Table]</link:label>
    <link:label id="lab_us-gaap_StatementTable_label_en-US" xlink:label="lab_us-gaap_StatementTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementTable" xlink:to="lab_us-gaap_StatementTable" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GCMGreenbackerAdministrationAndGreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember_019f7115-c76d-7cfd-87fe-8d827489e56b_terseLabel_en-US" xlink:label="lab_cik0001563922_GCMGreenbackerAdministrationAndGreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Acquired Entities</link:label>
    <link:label id="lab_cik0001563922_GCMGreenbackerAdministrationAndGreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember_label_en-US" xlink:label="lab_cik0001563922_GCMGreenbackerAdministrationAndGreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">GCM, Greenbacker Administration and Greenbacker Development Opportunities GP I, LLC ("GDEV GP") [Member]</link:label>
    <link:label id="lab_cik0001563922_GCMGreenbackerAdministrationAndGreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember_documentation_en-US" xlink:label="lab_cik0001563922_GCMGreenbackerAdministrationAndGreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">GCM, Greenbacker Administration and Greenbacker Development Opportunities GP I, LLC ("GDEV GP")</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GCMGreenbackerAdministrationAndGreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GCMGreenbackerAdministrationAndGreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GCMGreenbackerAdministrationAndGreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember" xlink:to="lab_cik0001563922_GCMGreenbackerAdministrationAndGreenbackerDevelopmentOpportunitiesGPILLCGDEVGPMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AdministrativeFeeRevenueMember_019f7115-c5e8-7c8d-9891-528bfde602a5_terseLabel_en-US" xlink:label="lab_cik0001563922_AdministrativeFeeRevenueMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Administrative fee, revenue</link:label>
    <link:label id="lab_cik0001563922_AdministrativeFeeRevenueMember_label_en-US" xlink:label="lab_cik0001563922_AdministrativeFeeRevenueMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Administrative Fee, Revenue [Member]</link:label>
    <link:label id="lab_cik0001563922_AdministrativeFeeRevenueMember_documentation_en-US" xlink:label="lab_cik0001563922_AdministrativeFeeRevenueMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Administrative Fee, Revenue</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AdministrativeFeeRevenueMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AdministrativeFeeRevenueMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_AdministrativeFeeRevenueMember" xlink:to="lab_cik0001563922_AdministrativeFeeRevenueMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredIncomeTaxExpenseBenefit_019f7115-c5e8-7b86-a410-0f1cffb47c31_totalLabel_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Deferred (benefit) provision for income taxes</link:label>
    <link:label id="lab_us-gaap_DeferredIncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred Income Tax Expense (Benefit)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="lab_us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019f7115-c671-7003-8368-a94e9d05b96d_terseLabel_en-US" xlink:label="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Adjustments to reconcile Net loss to Net cash provided by (used in) operating activities:</link:label>
    <link:label id="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsPPAMember_019f7115-c671-740a-80ff-ddf1404bf634_terseLabel_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsPPAMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Power Purchase Agreements ("PPA")</link:label>
    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsPPAMember_019f7115-c671-7812-9358-47a742d2c0dd_verboseLabel_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsPPAMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">PPA contracts</link:label>
    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsPPAMember_label_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsPPAMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Power Purchase Agreements ("PPA") [Member]</link:label>
    <link:label id="lab_cik0001563922_PowerPurchaseAgreementsPPAMember_documentation_en-US" xlink:label="lab_cik0001563922_PowerPurchaseAgreementsPPAMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Power Purchase Agreements ("PPA")</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_PowerPurchaseAgreementsPPAMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_PowerPurchaseAgreementsPPAMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_PowerPurchaseAgreementsPPAMember" xlink:to="lab_cik0001563922_PowerPurchaseAgreementsPPAMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019f7115-c5e8-7698-9798-b2abf99bad40_verboseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Cash Flows from Financing Activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFour_019f7115-c671-726e-87b8-4b7c6f4fff8e_terseLabel_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2029-2030</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFour_label_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, Rolling Year Four</link:label>
    <link:label id="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFour_documentation_en-US" xlink:label="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFour" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Commitment To Sell Renewable Energy Credit, Rolling Year Four</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFour" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFour"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFour" xlink:to="lab_cik0001563922_CommitmentToSellRenewableEnergyCreditRollingYearFour" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SalesRevenueNetMember_019f7115-c671-7c00-b628-85db4898e8b6_terseLabel_en-US" xlink:label="lab_us-gaap_SalesRevenueNetMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenue Benchmark</link:label>
    <link:label id="lab_us-gaap_SalesRevenueNetMember_label_en-US" xlink:label="lab_us-gaap_SalesRevenueNetMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue Benchmark [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SalesRevenueNetMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SalesRevenueNetMember" xlink:to="lab_us-gaap_SalesRevenueNetMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ContractWithCustomerTermOfContract_019f7115-c554-78d7-b448-1bc185d0e483_terseLabel_en-US" xlink:label="lab_cik0001563922_ContractWithCustomerTermOfContract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Term of contract (in years)</link:label>
    <link:label id="lab_cik0001563922_ContractWithCustomerTermOfContract_label_en-US" xlink:label="lab_cik0001563922_ContractWithCustomerTermOfContract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract With Customer, Term Of Contract</link:label>
    <link:label id="lab_cik0001563922_ContractWithCustomerTermOfContract_documentation_en-US" xlink:label="lab_cik0001563922_ContractWithCustomerTermOfContract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Contract With Customer, Term Of Contract</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ContractWithCustomerTermOfContract" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ContractWithCustomerTermOfContract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ContractWithCustomerTermOfContract" xlink:to="lab_cik0001563922_ContractWithCustomerTermOfContract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities_019f7115-c76d-7117-a42a-771b3e3a9f3e_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Return of collateral paid for swap contract</link:label>
    <link:label id="lab_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities_label_en-US" xlink:label="lab_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from Derivative Instrument, Financing Activities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities" xlink:to="lab_us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SharesIssued_019f7115-c5e8-7213-9047-1c6ffd5cfb97_terseLabel_en-US" xlink:label="lab_us-gaap_SharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Shares issued (in shares)</link:label>
    <link:label id="lab_us-gaap_SharesIssued_label_en-US" xlink:label="lab_us-gaap_SharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares, Issued</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesIssued"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharesIssued" xlink:to="lab_us-gaap_SharesIssued" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ContractWithCustomerLiability_019f7115-c6fc-7b9c-ba17-ae3fcb3f99bb_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contract liability</link:label>
    <link:label id="lab_us-gaap_ContractWithCustomerLiability_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract with Customer, Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiability"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ContractWithCustomerLiability" xlink:to="lab_us-gaap_ContractWithCustomerLiability" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GRECHoldings1LLCMember_019f7115-c671-7299-902b-1664af33ac38_terseLabel_en-US" xlink:label="lab_cik0001563922_GRECHoldings1LLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GREC Holdings 1 LLC</link:label>
    <link:label id="lab_cik0001563922_GRECHoldings1LLCMember_label_en-US" xlink:label="lab_cik0001563922_GRECHoldings1LLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">GREC Holdings 1 LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_GRECHoldings1LLCMember_documentation_en-US" xlink:label="lab_cik0001563922_GRECHoldings1LLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">GREC Holdings 1 LLC</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GRECHoldings1LLCMember" xlink:to="lab_cik0001563922_GRECHoldings1LLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityNoncurrent_019f7115-c671-7bdc-8b36-526453f4c5ac_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Other long-term liabilities</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityNoncurrent_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:to="lab_us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_019f7115-c671-7d06-bc7b-7573d52d9739_terseLabel_en-US" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Organization and Operations of the Company</link:label>
    <link:label id="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:to="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_019f7115-c671-7ac9-be77-e1919c4f79f4_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Fair Value Assets and Liabilities Using Level 3 Inputs</link:label>
    <link:label id="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_label_en-US" xlink:label="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:to="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f7115-c671-781d-8416-054894437192_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table]</link:label>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:to="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_AmendmentFlag_019f7115-c5e8-779b-88bb-aa8746d03894_terseLabel_en-US" xlink:label="lab_dei_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amendment Flag</link:label>
    <link:label id="lab_dei_AmendmentFlag_label_en-US" xlink:label="lab_dei_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amendment Flag</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AmendmentFlag" xlink:to="lab_dei_AmendmentFlag" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationCurrent_019f7115-c6fc-7bc5-a209-62a0dea59529_terseLabel_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Failed sale-leaseback financing, current</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationCurrent_label_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Financing Obligation, Current</link:label>
    <link:label id="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationCurrent_documentation_en-US" xlink:label="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Failed Sale Leaseback Transaction, Financing Obligation, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationCurrent" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FailedSaleLeasebackTransactionFinancingObligationCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationCurrent" xlink:to="lab_cik0001563922_FailedSaleLeasebackTransactionFinancingObligationCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNet_019f7115-c6fc-7c04-b1c2-0d620b993b6f_totalLabel_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNet_label_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets And Liabilities, Net</link:label>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNet_documentation_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets And Liabilities, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNet" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNet" xlink:to="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities_019f7115-c671-7c9f-a75b-989589e58c65_verboseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Other noncurrent liabilities</link:label>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities_label_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities" xlink:to="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_019f7115-c671-7197-b39f-0a20fa5cc3b7_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tranche 3 Earnout Shares</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement, Tranche Three [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationAwardTrancheThreeMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:to="lab_us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FinancingObligationImputedInterestRate_019f7115-c5e8-7d45-aecf-54c0c2ac5752_terseLabel_en-US" xlink:label="lab_cik0001563922_FinancingObligationImputedInterestRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Imputed interest rate for financing obligation</link:label>
    <link:label id="lab_cik0001563922_FinancingObligationImputedInterestRate_label_en-US" xlink:label="lab_cik0001563922_FinancingObligationImputedInterestRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Financing Obligation, Imputed Interest Rate</link:label>
    <link:label id="lab_cik0001563922_FinancingObligationImputedInterestRate_documentation_en-US" xlink:label="lab_cik0001563922_FinancingObligationImputedInterestRate" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Financing Obligation, Imputed Interest Rate</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FinancingObligationImputedInterestRate" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FinancingObligationImputedInterestRate"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FinancingObligationImputedInterestRate" xlink:to="lab_cik0001563922_FinancingObligationImputedInterestRate" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_019f7115-c671-7253-b510-72a1386f4137_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Weighted average discount rate &#8211; operating leases</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Weighted Average Discount Rate, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:to="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SaleOfStockSharesOfferedDividendReinvestmentPlan_019f7115-c671-7cbd-bb48-eaf1614bc569_terseLabel_en-US" xlink:label="lab_cik0001563922_SaleOfStockSharesOfferedDividendReinvestmentPlan" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Shares offered, DRP</link:label>
    <link:label id="lab_cik0001563922_SaleOfStockSharesOfferedDividendReinvestmentPlan_label_en-US" xlink:label="lab_cik0001563922_SaleOfStockSharesOfferedDividendReinvestmentPlan" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale Of Stock, Shares Offered, Dividend Reinvestment Plan</link:label>
    <link:label id="lab_cik0001563922_SaleOfStockSharesOfferedDividendReinvestmentPlan_documentation_en-US" xlink:label="lab_cik0001563922_SaleOfStockSharesOfferedDividendReinvestmentPlan" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sale Of Stock, Shares Offered, Dividend Reinvestment Plan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_SaleOfStockSharesOfferedDividendReinvestmentPlan" xlink:href="cik0001563922-20260810.xsd#cik0001563922_SaleOfStockSharesOfferedDividendReinvestmentPlan"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_SaleOfStockSharesOfferedDividendReinvestmentPlan" xlink:to="lab_cik0001563922_SaleOfStockSharesOfferedDividendReinvestmentPlan" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019f7115-c671-71b9-a455-1f24613a1a29_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Basic (in shares)</link:label>
    <link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019f7115-c671-7646-a269-fdca9bbcc4c6_verboseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Weighted average common shares outstanding used in computing net loss per share&#8212;basic (in shares)</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
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    <link:label id="lab_cik0001563922_DogwoodGBManagerLLCMember_label_en-US" xlink:label="lab_cik0001563922_DogwoodGBManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dogwood GB Manager LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_DogwoodGBManagerLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_DogwoodGBManagerLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Dogwood GB Manager LLC</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DogwoodGBManagerLLCMember" xlink:to="lab_cik0001563922_DogwoodGBManagerLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019f7115-c5e8-7dfd-895e-d0f1a5d2e59b_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table]</link:label>
    <link:label id="lab_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:to="lab_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SubsequentEventsAbstract_019f7115-c5e8-7ff5-bfb4-62462de6feb3_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Events [Abstract]</link:label>
    <link:label id="lab_us-gaap_SubsequentEventsAbstract_label_en-US" xlink:label="lab_us-gaap_SubsequentEventsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Events [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventsAbstract" xlink:to="lab_us-gaap_SubsequentEventsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SegmentReportingAbstract_label_en-US" xlink:label="lab_us-gaap_SegmentReportingAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segment Reporting [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SegmentReportingAbstract" xlink:to="lab_us-gaap_SegmentReportingAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CapitalizedContractCostImpairmentLoss_019f7115-c6fc-77ba-abc0-456c37317d19_terseLabel_en-US" xlink:label="lab_us-gaap_CapitalizedContractCostImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Capitalized cost, impairment loss</link:label>
    <link:label id="lab_us-gaap_CapitalizedContractCostImpairmentLoss_label_en-US" xlink:label="lab_us-gaap_CapitalizedContractCostImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Capitalized Contract Cost, Impairment Loss</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostImpairmentLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedContractCostImpairmentLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CapitalizedContractCostImpairmentLoss" xlink:to="lab_us-gaap_CapitalizedContractCostImpairmentLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtDisclosureAbstract_019f7115-c76d-7e71-80b2-2759d067477d_terseLabel_en-US" xlink:label="lab_us-gaap_DebtDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Disclosure [Abstract]</link:label>
    <link:label id="lab_us-gaap_DebtDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_DebtDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Disclosure [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtDisclosureAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtDisclosureAbstract" xlink:to="lab_us-gaap_DebtDisclosureAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsBrokerFee_019f7115-c6fc-72e6-bfb7-9e6fd07fcccb_terseLabel_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsBrokerFee" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Less: transaction costs</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsBrokerFee_label_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsBrokerFee" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operations, Broker Fee</link:label>
    <link:label id="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsBrokerFee_documentation_en-US" xlink:label="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsBrokerFee" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operations, Broker Fee</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsBrokerFee" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DisposalGroupIncludingDiscontinuedOperationsBrokerFee"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsBrokerFee" xlink:to="lab_cik0001563922_DisposalGroupIncludingDiscontinuedOperationsBrokerFee" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_ScenarioUnspecifiedDomain_019f7115-c5e8-7326-aa36-6dfac3f121b0_terseLabel_en-US" xlink:label="lab_srt_ScenarioUnspecifiedDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Scenario [Domain]</link:label>
    <link:label id="lab_srt_ScenarioUnspecifiedDomain_label_en-US" xlink:label="lab_srt_ScenarioUnspecifiedDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Scenario [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ScenarioUnspecifiedDomain" xlink:to="lab_srt_ScenarioUnspecifiedDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NumberOfSoldStorageOperatingPortfolio_019f7115-c554-702c-8c06-edbefc6f897e_terseLabel_en-US" xlink:label="lab_cik0001563922_NumberOfSoldStorageOperatingPortfolio" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of sold storage operating portfolio</link:label>
    <link:label id="lab_cik0001563922_NumberOfSoldStorageOperatingPortfolio_label_en-US" xlink:label="lab_cik0001563922_NumberOfSoldStorageOperatingPortfolio" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number Of Sold Storage Operating Portfolio</link:label>
    <link:label id="lab_cik0001563922_NumberOfSoldStorageOperatingPortfolio_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfSoldStorageOperatingPortfolio" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number Of Sold Storage Operating Portfolio</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NumberOfSoldStorageOperatingPortfolio" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NumberOfSoldStorageOperatingPortfolio"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NumberOfSoldStorageOperatingPortfolio" xlink:to="lab_cik0001563922_NumberOfSoldStorageOperatingPortfolio" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable_019f7115-c671-7df4-8695-7249a291e7a1_terseLabel_en-US" xlink:label="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, Plant, and Equipment, Lessor Asset under Operating Lease [Table]</link:label>
    <link:label id="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable_label_en-US" xlink:label="lab_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant, and Equipment, Lessor Asset under Operating Lease [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseByMajorPropertyClassTable"/>
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    <link:label id="lab_us-gaap_OtherCommitmentFiscalYearMaturityAbstract_019f7115-c76d-75c3-b380-c640dbc379ef_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCommitmentFiscalYearMaturityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amount</link:label>
    <link:label id="lab_us-gaap_OtherCommitmentFiscalYearMaturityAbstract_label_en-US" xlink:label="lab_us-gaap_OtherCommitmentFiscalYearMaturityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Commitment, Fiscal Year Maturity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentFiscalYearMaturityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentFiscalYearMaturityAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCommitmentFiscalYearMaturityAbstract" xlink:to="lab_us-gaap_OtherCommitmentFiscalYearMaturityAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f7115-c5e8-7df5-9172-2f4ce72c2fcb_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
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    <link:label id="lab_srt_ConsolidatedEntitiesAxis_019f7115-c6fc-73cc-8d80-c3539aa4e88c_terseLabel_en-US" xlink:label="lab_srt_ConsolidatedEntitiesAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Consolidated Entities [Axis]</link:label>
    <link:label id="lab_srt_ConsolidatedEntitiesAxis_label_en-US" xlink:label="lab_srt_ConsolidatedEntitiesAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidated Entities [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ConsolidatedEntitiesAxis" xlink:to="lab_srt_ConsolidatedEntitiesAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommonStockParOrStatedValuePerShare_019f7115-c555-706b-81a4-9dfb5fce5386_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common shares, par value (in dollars per share)</link:label>
    <link:label id="lab_us-gaap_CommonStockParOrStatedValuePerShare_label_en-US" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock, Par or Stated Value Per Share</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
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    <link:label id="lab_cik0001563922_ClassPSSharesMember_019f7115-c6fc-7d32-8815-c74b52d769e2_terseLabel_en-US" xlink:label="lab_cik0001563922_ClassPSSharesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class P-S</link:label>
    <link:label id="lab_cik0001563922_ClassPSSharesMember_label_en-US" xlink:label="lab_cik0001563922_ClassPSSharesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class P-S Shares [Member]</link:label>
    <link:label id="lab_cik0001563922_ClassPSSharesMember_documentation_en-US" xlink:label="lab_cik0001563922_ClassPSSharesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Class P-S Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ClassPSSharesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ClassPSSharesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ClassPSSharesMember" xlink:to="lab_cik0001563922_ClassPSSharesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths_019f7115-c5e8-7859-8fd6-bce0796487ab_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026-2027</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, to be Paid, Next Rolling 12 Months</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths"/>
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    <link:label id="lab_cik0001563922_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_019f7115-c555-7bae-867c-e771a296969e_terseLabel_en-US" xlink:label="lab_cik0001563922_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Finance leases</link:label>
    <link:label id="lab_cik0001563922_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_label_en-US" xlink:label="lab_cik0001563922_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Assets And Liabilities, Lessee [Abstract]</link:label>
    <link:label id="lab_cik0001563922_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract_documentation_en-US" xlink:label="lab_cik0001563922_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Finance Lease, Assets And Liabilities, Lessee</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract" xlink:to="lab_cik0001563922_FinanceLeaseAssetsAndLiabilitiesLesseeAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_SharesWithHeldRelatedToNetSettlementOfEquityAwards_019f7115-c671-7354-94a7-90bf9892f373_negatedTerseLabel_en-US" xlink:label="lab_cik0001563922_SharesWithHeldRelatedToNetSettlementOfEquityAwards" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Shares withheld related to net share settlement of equity awards</link:label>
    <link:label id="lab_cik0001563922_SharesWithHeldRelatedToNetSettlementOfEquityAwards_label_en-US" xlink:label="lab_cik0001563922_SharesWithHeldRelatedToNetSettlementOfEquityAwards" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Shares With held Related To Net Settlement Of Equity Awards</link:label>
    <link:label id="lab_cik0001563922_SharesWithHeldRelatedToNetSettlementOfEquityAwards_documentation_en-US" xlink:label="lab_cik0001563922_SharesWithHeldRelatedToNetSettlementOfEquityAwards" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Shares With held Related To Net Settlement Of Equity Awards</link:label>
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    <link:label id="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesDevelopmentFeeReceivable_documentation_en-US" xlink:label="lab_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesDevelopmentFeeReceivable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Divestiture Of Interest In Consolidated Subsidiaries, Development Fee Receivable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesDevelopmentFeeReceivable" xlink:href="cik0001563922-20260810.xsd#cik0001563922_DivestitureOfInterestInConsolidatedSubsidiariesDevelopmentFeeReceivable"/>
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    <link:label id="lab_us-gaap_UseOfEstimates_019f7115-c671-7716-8977-377f4efe8c53_terseLabel_en-US" xlink:label="lab_us-gaap_UseOfEstimates" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Use of Estimates</link:label>
    <link:label id="lab_us-gaap_UseOfEstimates_label_en-US" xlink:label="lab_us-gaap_UseOfEstimates" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Use of Estimates, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UseOfEstimates" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UseOfEstimates"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UseOfEstimates" xlink:to="lab_us-gaap_UseOfEstimates" xlink:type="arc" order="1"/>
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    <link:label id="lab_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitionsShares_documentation_en-US" xlink:label="lab_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitionsShares" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Temporary Equity, Stock Issued During Period, Earnout Shares, Acquisitions, Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitionsShares" xlink:href="cik0001563922-20260810.xsd#cik0001563922_TemporaryEquityStockIssuedDuringPeriodEarnoutSharesAcquisitionsShares"/>
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    <link:label id="lab_us-gaap_GuaranteeObligationsByNatureAxis_019f7115-c6fc-7509-afdd-49c594f9dddf_terseLabel_en-US" xlink:label="lab_us-gaap_GuaranteeObligationsByNatureAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Guarantor Obligations, Nature [Axis]</link:label>
    <link:label id="lab_us-gaap_GuaranteeObligationsByNatureAxis_label_en-US" xlink:label="lab_us-gaap_GuaranteeObligationsByNatureAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Guarantor Obligations, Nature [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GuaranteeObligationsByNatureAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis" xlink:to="lab_us-gaap_GuaranteeObligationsByNatureAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability_019f7115-c671-7f99-b124-b506d3db8a67_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Operating cash flows from finance leases</link:label>
    <link:label id="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Interest Payment on Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseInterestPaymentOnLiability"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:to="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConstructionInProgressGross_019f7115-c5e8-7acf-b7bc-34f86e6839a2_terseLabel_en-US" xlink:label="lab_us-gaap_ConstructionInProgressGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Construction in progress</link:label>
    <link:label id="lab_us-gaap_ConstructionInProgressGross_label_en-US" xlink:label="lab_us-gaap_ConstructionInProgressGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Construction in Progress, Gross</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressGross" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionInProgressGross"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConstructionInProgressGross" xlink:to="lab_us-gaap_ConstructionInProgressGross" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIOYALenderLLCGDEVOYALenderMember_019f7115-c554-76df-bfdd-15dff1ce0749_terseLabel_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIOYALenderLLCGDEVOYALenderMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GDEV OYA Lender</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIOYALenderLLCGDEVOYALenderMember_label_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIOYALenderLLCGDEVOYALenderMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities Fund I, OYA Lender LLC ("GDEV OYA Lender") [Member]</link:label>
    <link:label id="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIOYALenderLLCGDEVOYALenderMember_documentation_en-US" xlink:label="lab_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIOYALenderLLCGDEVOYALenderMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Greenbacker Development Opportunities Fund I, OYA Lender LLC ("GDEV OYA Lender")</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GreenbackerDevelopmentOpportunitiesFundIOYALenderLLCGDEVOYALenderMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GreenbackerDevelopmentOpportunitiesFundIOYALenderLLCGDEVOYALenderMember"/>
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    <link:label id="lab_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicy_019f7115-c671-72ae-8f67-63289134aa80_terseLabel_en-US" xlink:label="lab_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Restructuring and Related Charges</link:label>
    <link:label id="lab_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicy_label_en-US" xlink:label="lab_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Costs Associated with Exit or Disposal Activity or Restructuring [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicy"/>
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    <link:label id="lab_cik0001563922_IllinoisWindsLLCMember_019f7115-c555-7d67-92eb-dd96c9b0e7a9_terseLabel_en-US" xlink:label="lab_cik0001563922_IllinoisWindsLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Illinois Winds LLC</link:label>
    <link:label id="lab_cik0001563922_IllinoisWindsLLCMember_label_en-US" xlink:label="lab_cik0001563922_IllinoisWindsLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Illinois Winds LLC [Member]</link:label>
    <link:label id="lab_cik0001563922_IllinoisWindsLLCMember_documentation_en-US" xlink:label="lab_cik0001563922_IllinoisWindsLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Illinois Winds LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_IllinoisWindsLLCMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_IllinoisWindsLLCMember"/>
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    <link:label id="lab_us-gaap_SubsequentEventsTextBlock_019f7115-c6fc-77d5-9894-18818583d7f0_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Events</link:label>
    <link:label id="lab_us-gaap_SubsequentEventsTextBlock_label_en-US" xlink:label="lab_us-gaap_SubsequentEventsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Events [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventsTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventsTextBlock" xlink:to="lab_us-gaap_SubsequentEventsTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_019f7115-c671-72ef-9c50-0038138f472f_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share Units</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward"/>
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    <link:label id="lab_us-gaap_InvestmentIncomeInterestAndDividend_019f7115-c671-73a5-aee7-cb21b405faab_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_InvestmentIncomeInterestAndDividend" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Less: Investment, dividend, interest and other income</link:label>
    <link:label id="lab_us-gaap_InvestmentIncomeInterestAndDividend_label_en-US" xlink:label="lab_us-gaap_InvestmentIncomeInterestAndDividend" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investment Income, Interest and Dividend</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterestAndDividend" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeInterestAndDividend"/>
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    <link:label id="lab_us-gaap_ReceivableWithImputedInterestEffectiveYieldInterestRate_019f7115-c6fc-7fce-989e-6c5b8e931784_terseLabel_en-US" xlink:label="lab_us-gaap_ReceivableWithImputedInterestEffectiveYieldInterestRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest rate</link:label>
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    <link:label id="lab_us-gaap_ProductAndServiceOtherMember_019f7115-c555-7bed-86b7-325b1b85d21f_terseLabel_en-US" xlink:label="lab_us-gaap_ProductAndServiceOtherMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other revenue</link:label>
    <link:label id="lab_us-gaap_ProductAndServiceOtherMember_019f7115-c555-730f-bfb0-0f438c84600e_netLabel_en-US" xlink:label="lab_us-gaap_ProductAndServiceOtherMember" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xml:lang="en-US">Other revenue</link:label>
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    <link:label id="lab_us-gaap_Liabilities_019f7115-c555-7ed2-8416-514c95e22b83_terseLabel_en-US" xlink:label="lab_us-gaap_Liabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Liabilities</link:label>
    <link:label id="lab_us-gaap_Liabilities_label_en-US" xlink:label="lab_us-gaap_Liabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Liabilities</link:label>
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    <link:label id="lab_us-gaap_MembersEquityNotesDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_MembersEquityNotesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Members' Equity Notes Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquityNotesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MembersEquityNotesDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MembersEquityNotesDisclosureTextBlock" xlink:to="lab_us-gaap_MembersEquityNotesDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_AECCompaniesMember_019f7115-c6fc-700d-9d2d-0f7892c6451b_terseLabel_en-US" xlink:label="lab_cik0001563922_AECCompaniesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">AEC Companies</link:label>
    <link:label id="lab_cik0001563922_AECCompaniesMember_label_en-US" xlink:label="lab_cik0001563922_AECCompaniesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">AEC Companies [Member]</link:label>
    <link:label id="lab_cik0001563922_AECCompaniesMember_documentation_en-US" xlink:label="lab_cik0001563922_AECCompaniesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">AEC Companies</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_AECCompaniesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_AECCompaniesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_AECCompaniesMember" xlink:to="lab_cik0001563922_AECCompaniesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentOtherTypesMember_019f7115-c6fc-7edd-aa49-ae6fe2eea646_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentOtherTypesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentOtherTypesMember_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentOtherTypesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment, Other Types [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentOtherTypesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentOtherTypesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentOtherTypesMember" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentOtherTypesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_NumberOfDevelopmentStageProjects_019f7115-c5e8-7e17-97cb-e952a119dcaf_terseLabel_en-US" xlink:label="lab_cik0001563922_NumberOfDevelopmentStageProjects" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of development stage projects</link:label>
    <link:label id="lab_cik0001563922_NumberOfDevelopmentStageProjects_label_en-US" xlink:label="lab_cik0001563922_NumberOfDevelopmentStageProjects" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number of Development Stage Projects</link:label>
    <link:label id="lab_cik0001563922_NumberOfDevelopmentStageProjects_documentation_en-US" xlink:label="lab_cik0001563922_NumberOfDevelopmentStageProjects" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number of Development Stage Projects</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_NumberOfDevelopmentStageProjects" xlink:href="cik0001563922-20260810.xsd#cik0001563922_NumberOfDevelopmentStageProjects"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_NumberOfDevelopmentStageProjects" xlink:to="lab_cik0001563922_NumberOfDevelopmentStageProjects" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ManufacturingFacilityMember_019f7115-c555-72ba-824b-ede578aae76a_terseLabel_en-US" xlink:label="lab_us-gaap_ManufacturingFacilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Manufacturing Facility</link:label>
    <link:label id="lab_us-gaap_ManufacturingFacilityMember_label_en-US" xlink:label="lab_us-gaap_ManufacturingFacilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Manufacturing Facility [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManufacturingFacilityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ManufacturingFacilityMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ManufacturingFacilityMember" xlink:to="lab_us-gaap_ManufacturingFacilityMember" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearTwo_019f7115-c6fc-71c6-b9c5-cdb7a396273e_terseLabel_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2027-2028</link:label>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearTwo_label_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets And Liabilities, Net, Expected Amortization, Rolling Year Two</link:label>
    <link:label id="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearTwo_documentation_en-US" xlink:label="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearTwo" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets And Liabilities, Net, Expected Amortization, Rolling Year Two</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearTwo" xlink:href="cik0001563922-20260810.xsd#cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearTwo"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearTwo" xlink:to="lab_cik0001563922_FiniteLivedIntangibleAssetsAndLiabilitiesNetExpectedAmortizationRollingYearTwo" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_CapitalizedLaborCostsMember_019f7115-c5e8-7e97-a603-1309fc7e6159_terseLabel_en-US" xlink:label="lab_cik0001563922_CapitalizedLaborCostsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Capitalized labor costs</link:label>
    <link:label id="lab_cik0001563922_CapitalizedLaborCostsMember_label_en-US" xlink:label="lab_cik0001563922_CapitalizedLaborCostsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Capitalized Labor Costs [Member]</link:label>
    <link:label id="lab_cik0001563922_CapitalizedLaborCostsMember_documentation_en-US" xlink:label="lab_cik0001563922_CapitalizedLaborCostsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Capitalized Labor Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_CapitalizedLaborCostsMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_CapitalizedLaborCostsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_CapitalizedLaborCostsMember" xlink:to="lab_cik0001563922_CapitalizedLaborCostsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNoncurrent_019f7115-c555-78b7-873c-517f92bdaa59_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Intangible assets, net</link:label>
    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNoncurrent_label_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operation, Intangible Assets, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNoncurrent" xlink:to="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_ClassPTAndPSSharesMember_019f7115-c671-785d-9f22-386c88d8bd9a_terseLabel_en-US" xlink:label="lab_cik0001563922_ClassPTAndPSSharesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class P-T and P-S Shares</link:label>
    <link:label id="lab_cik0001563922_ClassPTAndPSSharesMember_label_en-US" xlink:label="lab_cik0001563922_ClassPTAndPSSharesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class P-T and P-S Shares [Member]</link:label>
    <link:label id="lab_cik0001563922_ClassPTAndPSSharesMember_documentation_en-US" xlink:label="lab_cik0001563922_ClassPTAndPSSharesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Class P-T and P-S Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_ClassPTAndPSSharesMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_ClassPTAndPSSharesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_ClassPTAndPSSharesMember" xlink:to="lab_cik0001563922_ClassPTAndPSSharesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_ConsolidationItemsAxis_019f7115-c6fc-7c3a-ae13-b55fecd68d2f_terseLabel_en-US" xlink:label="lab_srt_ConsolidationItemsAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Consolidation Items [Axis]</link:label>
    <link:label id="lab_srt_ConsolidationItemsAxis_label_en-US" xlink:label="lab_srt_ConsolidationItemsAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidation Items [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ConsolidationItemsAxis" xlink:to="lab_srt_ConsolidationItemsAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_UpfrontPaymentsToCustomersImpairmentLoss_019f7115-c555-7ff8-a0e9-3510ac7d2d62_terseLabel_en-US" xlink:label="lab_cik0001563922_UpfrontPaymentsToCustomersImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Upfront payments to customers, impairment loss</link:label>
    <link:label id="lab_cik0001563922_UpfrontPaymentsToCustomersImpairmentLoss_label_en-US" xlink:label="lab_cik0001563922_UpfrontPaymentsToCustomersImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Upfront Payments To Customers, Impairment Loss</link:label>
    <link:label id="lab_cik0001563922_UpfrontPaymentsToCustomersImpairmentLoss_documentation_en-US" xlink:label="lab_cik0001563922_UpfrontPaymentsToCustomersImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Upfront Payments To Customers, Impairment Loss</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_UpfrontPaymentsToCustomersImpairmentLoss" xlink:href="cik0001563922-20260810.xsd#cik0001563922_UpfrontPaymentsToCustomersImpairmentLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_UpfrontPaymentsToCustomersImpairmentLoss" xlink:to="lab_cik0001563922_UpfrontPaymentsToCustomersImpairmentLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_CounterpartyNameAxis_019f7115-c671-7380-9951-713778504f0d_terseLabel_en-US" xlink:label="lab_srt_CounterpartyNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Counterparty Name [Axis]</link:label>
    <link:label id="lab_srt_CounterpartyNameAxis_label_en-US" xlink:label="lab_srt_CounterpartyNameAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Counterparty Name [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CounterpartyNameAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_CounterpartyNameAxis" xlink:to="lab_srt_CounterpartyNameAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock_019f7115-c555-75d0-af84-e1865c4ae905_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Restricted Share Unit Activity</link:label>
    <link:label id="lab_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DistributionTypeDomain_019f7115-c6fc-702f-8300-444d8dab6840_terseLabel_en-US" xlink:label="lab_us-gaap_DistributionTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distribution Type [Domain]</link:label>
    <link:label id="lab_us-gaap_DistributionTypeDomain_label_en-US" xlink:label="lab_us-gaap_DistributionTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distribution Type [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DistributionTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DistributionTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DistributionTypeDomain" xlink:to="lab_us-gaap_DistributionTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_019f7115-c554-7d7e-b097-c720111d1f47_terseLabel_en-US" xlink:label="lab_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration]</link:label>
    <link:label id="lab_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_label_en-US" xlink:label="lab_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:to="lab_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:type="arc" order="1"/>
    <link:label id="lab_cik0001563922_GreenbackerRenewableEnergyCompanyIILLCGRECIIMember_019f7115-c5e8-729d-b0aa-8301b976bf71_terseLabel_en-US" xlink:label="lab_cik0001563922_GreenbackerRenewableEnergyCompanyIILLCGRECIIMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GREC II</link:label>
    <link:label id="lab_cik0001563922_GreenbackerRenewableEnergyCompanyIILLCGRECIIMember_label_en-US" xlink:label="lab_cik0001563922_GreenbackerRenewableEnergyCompanyIILLCGRECIIMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Greenbacker Renewable Energy Company II, LLC ("GREC II") [Member]</link:label>
    <link:label id="lab_cik0001563922_GreenbackerRenewableEnergyCompanyIILLCGRECIIMember_documentation_en-US" xlink:label="lab_cik0001563922_GreenbackerRenewableEnergyCompanyIILLCGRECIIMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Greenbacker Renewable Energy Company II, LLC ("GREC II")</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_cik0001563922_GreenbackerRenewableEnergyCompanyIILLCGRECIIMember" xlink:href="cik0001563922-20260810.xsd#cik0001563922_GreenbackerRenewableEnergyCompanyIILLCGRECIIMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_cik0001563922_GreenbackerRenewableEnergyCompanyIILLCGRECIIMember" xlink:to="lab_cik0001563922_GreenbackerRenewableEnergyCompanyIILLCGRECIIMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_TaxCreditCarryforwardNameDomain_019f7115-c554-7518-8ceb-9690efe5b989_terseLabel_en-US" xlink:label="lab_us-gaap_TaxCreditCarryforwardNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tax Credit Carryforward, Name [Domain]</link:label>
    <link:label id="lab_us-gaap_TaxCreditCarryforwardNameDomain_label_en-US" xlink:label="lab_us-gaap_TaxCreditCarryforwardNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Tax Credit Carryforward, Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TaxCreditCarryforwardNameDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TaxCreditCarryforwardNameDomain" xlink:to="lab_us-gaap_TaxCreditCarryforwardNameDomain" xlink:type="arc" order="1"/>
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