Exhibit 99.1

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM ABS DUE DILIGENCE-15E

CERTIFICATION OF PROVIDER OF THIRD-PARTY DUE DILIGENCE SERVICES FOR

ASSET-BACKED SECURITIES

 

Item 1. Identity of the person providing third-party due diligence services

KPMG LLP

20 Pacifica, Suite 700

Irvine, CA 92618

Item 2. Identity of the person who paid the person to provide third-party due diligence services

Sunrun Inc.

600 California St. #1800

San Francisco, CA 94108

Item 3. Credit rating criteria

If the due diligence performed by the third party is intended to satisfy the criteria for due diligence published by a nationally recognized statistical rating organization, identify the nationally recognized statistical rating organization and the title and date of the published criteria (more than one nationally recognized statistical rating organization may be identified).

KPMG LLP was not engaged to perform procedures that were intended to satisfy any criteria for due diligence published by a nationally recognized statistical rating organization.

Item 4. Description of the due diligence performed

Provide a description of the scope and manner of the due diligence services performed in connection with the review of assets that is sufficiently detailed to provide an understanding of the steps taken in performing the review. Include in the description: (1) the type of assets that were reviewed; (2) the sample size of the assets reviewed; (3) how the sample size was determined and, if applicable, computed; (4) whether the accuracy of information or data about the assets provided, directly or indirectly, by the securitizer or originator of the assets was reviewed and, if so, how the review was conducted; (5) whether the conformity of the origination of the assets to stated underwriting or credit extension guidelines, standards, criteria or other requirements was reviewed and, if so, how the review was conducted; (6) whether the value of collateral securing such assets was reviewed and, if so, how the review was conducted; (7) whether the compliance of the originator of the assets with federal, state, and local laws and regulations was reviewed and, if so, how the review was conducted; and (8) any other type of review that was part of the due diligence services conducted by the person executing this Form. This description should be attached to the Form and contain the heading “Item 4.” Provide this description regardless of whether the due diligence performed is intended to satisfy the criteria for due diligence published by a nationally recognized statistical rating organization.

The Report contains a description of the following (numbers correspond to the requested description items): 

 

(1)

See attached Independent Accountants’ Agreed-Upon Procedures Report dated April 17, 2026, pertaining to Sunrun Prometheus Issuer 2026-1, LLC.

 

(2)

See attached Independent Accountants’ Agreed-Upon Procedures Report dated April 17, 2026, pertaining to Sunrun Prometheus Issuer 2026-1, LLC.

 

(3)

See attached Independent Accountants’ Agreed-Upon Procedures Report dated April 17, 2026, pertaining to Sunrun Prometheus Issuer 2026-1, LLC.

 

(4)

See attached Independent Accountants’ Agreed-Upon Procedures Report dated April 17, 2026, pertaining to Sunrun Prometheus Issuer 2026-1, LLC.

 

(5)

Not applicable

 

(6)

Not applicable

 

(7)

Not applicable

 

(8)

None

Item 5. Summary of findings and conclusions of review

Provide a summary of the findings and conclusions that resulted from the due diligence services that is sufficiently detailed to provide an understanding of the findings and conclusions that were conveyed to the person identified in Item 2. This summary should be attached to the Form and contain the heading “Item 5.”

The findings can be found in the attached Independent Accountants’ Agreed-Upon Procedures Report dated April 17, 2026. Consistent with American Institute of Certified Public Accountants attestation standards, there were no conclusions that resulted from the due diligence services. KPMG LLP was not engaged to, and did not, conduct an examination or review, the objective of which would be the expression of an opinion or conclusion, respectively, on the Data File (as defined in the attached Independent Accountants’ Agreed-Upon Procedures Report dated April 17, 2026, pertaining to Sunrun Prometheus Issuer 2026-1, LLC).

CERTIFICATION

The undersigned has executed this Form ABS Due Diligence 15E on behalf of, and on the authority of, the person identified in Item 1 of the Form. The undersigned, on behalf of the person, represents that the person identified in Item 1 of the Form conducted a thorough review in performing the due diligence described in Item 4 attached to this Form and that the information and statements contained in this Form, including Item 4 attached to this Form, which are part of this Form, are accurate in all significant respects on and as of the date hereof.

For purposes of this certification, consistent with attestation standards established by the American Institute of Certified Public Accountants, we were not engaged to, and did not, conduct an examination or review, the objective of which would be the expression of an opinion or conclusion, respectively, on the Data File (as defined in the attached Independent Accountants’ Agreed-Upon Procedures Report dated April 17, 2026, pertaining to Sunrun Prometheus Issuer 2026-1, LLC).

Name of Person Identified in Item 1: KPMG LLP             

 

By: Tina M. Stoliar, Partner		/s/ Tina M. Stoliar
(Print name of duly authorized person)		(Signature)
Date: April 17, 2026

		KPMG LLP
		Suite 700 20 Pacifica
		Irvine, CA 92618-3391

Independent Accountants’ Agreed-Upon Procedures Report

Sunrun Inc. (the “Company”)

ATLAS SP Securities, a division of Apollo Global Securities, LLC

Atlas SP Partners, L. P.

(together, the “Specified Parties”)

Re: Sunrun Prometheus Issuer 2026-1, LLC – Data File Procedures

We have performed the procedures described below on the specified attributes in an electronic data file entitled “Prometheus 2026-1 Data Tape (2026.03.25).xlsx” provided by the Company on March 25, 2026, containing information on 38,706 solar assets (the “Solar Assets”) as of February 28, 2026 (the “Data File”), which we were informed are intended to be included as collateral in the offering by Sunrun Prometheus Issuer 2026-1, LLC. The Company is responsible for the specified attributes identified by the Company in the Data File.

The Specified Parties have agreed to and acknowledged that the procedures performed are appropriate to meet the intended purpose of assisting specified parties in evaluating the accuracy of the specified attributes in the Data File. This report may not be suitable for any other purpose. No other parties have agreed to or acknowledged the appropriateness of these procedures for the intended purpose or any other purpose.

The procedures performed may not address all the items of interest to a specified party of this report and may not meet the needs of all specified parties of this report and, as such, specified parties are responsible for determining whether the procedures performed are appropriate for their purposes. We make no representation regarding the appropriateness of the procedures either for the intended purpose or for any other purpose.

Unless otherwise stated, the following definitions have been adopted in presenting our procedures and findings:

 

•

The term “compared” means compared to the information shown and found it to be in agreement, unless otherwise stated. Such compared information was deemed to be in agreement if differences were within the reporting threshold.

 

•

The term “recomputed” means recalculated and compared the result to the information shown and found it to be in agreement, unless otherwise stated. Such recomputed information was deemed to be in agreement if differences were within the reporting threshold.

 

•

The term “reporting threshold” means that dollar amounts and percentages were within $1.00 and 0.1%, respectively, unless otherwise stated.

 

•

The term “Solar Asset Contracts” means some or all of the following documents provided by the Company for each Selected Asset (defined below): the residential solar power purchase agreement, residential power purchase agreement, power purchase agreement, solar facility addendum contract, solar as built proposal, residential solar system lease agreement, amendment to the residential solar power purchase agreement, net energy metering agreement, customer approved plan, PV designer report, PV plan set report, PV system site plan, PV system roof plan, utility bill, customer invoice, change order documentation, and/or lease disclosure thereto. The Solar Asset Contracts were represented by the Company to be a copy of the original Solar Asset Contracts and/or electronic records contained within the Company’s servicing system. We make no representation regarding the validity or accuracy of the Solar Asset Contracts or the execution of the Solar Asset Contracts by the signors.

 

 

•

The term “PTO Notification” means the notice provided by the Company identifying the date on which the utility provider confirmed the Selected Asset was granted permission-to-operate (PTO) on the electrical grid.

 

•

The term “PBI Support” means performance-based incentive contracts associated with each applicable Selected Asset provided by the Company on December 17, 2025.

 

•

The term “Sample Selection File I” means an electronic data file entitled “03 Prometheus 2026-1 RA Tape (as of 10.31.2025).xlsx” provided by the Company on December 11, 2025, containing information on 47,581 Solar Assets as of October 31, 2025.

 

•

The term “Sample Selection File II” means an electronic data file entitled “08 Prometheus 2026-1 RA Tape (2026.03.16).xlsx” provided by the Company on March 17, 2026, containing information on 38,706 Solar Assets as of February 28, 2026.

 

•

The term “FICO & ACH Support” means two (2) electronic data files entitled “FICO and Billing Method Data vF.xlsx” and “FICO and Billing Method Data (3.30.2026).vF.xlsx” provided by the Company on December 23, 2025, and March 30, 2026, respectively, containing credit report scores and billing type information associated with each Selected Asset.

 

•

The term “Additional Billing Type Support” means servicing system screenshots provided by the Company on April 6, 2026, containing information on billing type for Selected Assets #5, 132, 161, 198 and 214.

 

•

The term “Additional Guaranteed Production Support” means electronic mail correspondence provided by the Company on April 6, 2026, containing information on guaranteed Production kWh (Year 25) for Selected Assets #36, 137 and 286.

 

•

The term “Company Mapping Support” means electronic mail correspondence provided by the Company on April 15, 2026, containing information on the abbreviations used for Panel Manufacturer, Utility Company, Inverter Manufacturer and Battery Manufacturer.

 

•

The term “Source Documents” means the Solar Asset Contracts, PTO Notification, PBI Support, Sample Selection File I, Sample Selection File II, FICO & ACH Support, Additional Billing Type Support, Additional Guaranteed Production Support and Company Mapping Support.

 

•

The term “Instructions” means the instructions provided by the Company pertaining to a procedure, attribute, methodology, or value, as described in Exhibit A.

 

•

The term “Provided Information” means the Source Documents and Instructions.

The procedures we were instructed by the Company to perform and the associated findings are as follows:

 

A.

We randomly selected a sample of (i) 219 Solar Assets from Sample Selection File I and (ii) 81 Solar Assets from Sample Selection File II for a total of 300 Solar Assets (the “Selected Assets”) using a random sampling tool. A listing of the Selected Assets is attached hereto as Exhibit B. For purposes of this procedure, the Company did not inform us of the basis they used to determine the number of Solar Assets we were instructed to randomly select from Sample Selection File I and Sample Selection File II.

 

2

 

B.

For each Selected Asset, we compared or recomputed the specified attributes in the Data File listed below to or using the corresponding information included in the Source Documents listed below in the Provided Information column, utilizing the Instructions, as applicable. The Specified Parties indicated that the absence of any of the information in the Source Documents or the inability to agree the indicated information from the Data File to the Source Documents for each of the attributes identified, utilizing the Instructions as applicable, constituted an exception. The Source Documents are listed in the order of priority, with the highest priority document listed first.

 

 

3

 

We found such information to be in agreement except as listed in Exhibit C.

We were engaged by the Company to perform this agreed-upon procedures engagement, We conducted our engagement in accordance with attestation standards established by the American Institute of Certified Public Accountants, which involves us performing the specific procedures agreed to and acknowledged above and reporting on findings based on performing those procedures. We were not engaged to, and did not, conduct an examination or review, the objective of which would be the expression of an opinion or conclusion, respectively, on the specified attributes in the Data File. Accordingly, we do not express such an opinion or conclusion. Had we performed additional procedures, other matters might have come to our attention that would have been reported.

We are required to be independent of the Company and to meet our other ethical responsibilities, in accordance with the relevant ethical requirements related to our agreed-upon procedures engagement.

The procedures performed were applied based on the information included in the Data File and Provided Information, without verification or evaluation of such information by us; therefore, we express no opinion or any other form of assurance regarding (i) the reasonableness of the information provided to us by the Company, (ii) the physical existence of the Solar Assets, (iii) the reliability or accuracy of the Provided Information which was used in our procedures, or (iv) matters of legal interpretation.

The procedures performed were not intended to address, nor did they address: (i) the conformity of the origination of the Solar Assets to stated underwriting or credit extension guidelines, standards, criteria or other requirements, (ii) the value of collateral securing any such Solar Assets being securitized, (iii) the compliance of the originator of the Solar Assets with federal, state, and local laws and regulations, or (iv) any other factor or characteristic of the Solar Assets that would be material to the likelihood that the issuer of the Notes will pay interest and principal in accordance with applicable terms and conditions. The procedures performed were not intended to satisfy any criteria for due diligence published by the nationally recognized statistical rating organizations (“NRSROs”).

The terms of our engagement are such that we have no responsibility to update this report because of events and circumstances that may subsequently occur.

This report is intended solely for the information and use of the Specified Parties. It is not intended to be and should not be used by any other person or entity, including investors or the NRSROs, who are not identified in the report as the Specified Parties but may have access to this report as required by law or regulation.

 

Irvine, California

April 17, 2026

 

4

Exhibit A

Instructions

 

Number		Attribute		Instructions
1.		System Size (kW)		Consider the attribute to be in agreement if it is within 0.1 kW of the Source Document value.
2.		Estimated Solar Generation Year 1 (kWh)		Consider the attribute to be in agreement if it is within 0.5% of the Source Document value.
3.		Performance Guarantee %		For Selected Assets for which the performance guarantee percentage is not included in the Solar Asset Contracts, recompute as guaranteed production included in the Solar Asset Contracts divided by Estimated Solar Generation Year 1 (kWh).   Consider the attribute to be in agreement if it is within 1% of the Source Document value.
4.		PeGu Payout Frequency		Do not perform this procedure for Selected Assets for which the Performance Guarantee % is 0.
5.		Battery Manufacturer		Do not perform this procedure for Selected Assets for which the Number of Batteries in the Date File is 0.
6.		Guaranteed Production (Year 15)		Consider the attribute to be in agreement if it is within the range of -2% to 15% of the Source Document value.   Do not perform this procedure for Selected Assets for which the Customer Agreement Term (Years) in the Date File is either 18, 20 or 25.
7.		Guaranteed Production (Year 18)		Consider the attribute to be in agreement if it is within the range of -2% to 15% of the Source Document value.   Do not perform this procedure for Selected Assets for which the Customer Agreement Term (Years) in the Date File is either 15, 20 or 25.
8.		Guaranteed Production (Year 20)		Consider the attribute to be in agreement if it is within the range of -2% to 15% of the Source Document value.   Do not perform this procedure for Selected Assets for which the Customer Agreement Term (Years) in the Date File is either 15, 18, or 25.
9.		Guaranteed Production (Year 25)		Consider the attribute to be in agreement if it is within the range of -2% to 15% of the Source Document value.   Do not perform this procedure for Selected Assets for which the Customer Agreement Term (Years) in the Date File is either 15, 18, or 20.
10.		PBI Rate ($/kWh)		For Selected Assets with a State of “NJ” in the Data File for which PBI Rate ($/kWh) is not equal to $0/kWh, use New Jersey’s Clean Energy’s website (listed below) to look up the PBI Rate:   https://cleanenergy.nj.gov/programs/solar/administratively-determined-incentive-adi-program .   Round Source Document value to 3 decimal places.   Do not perform this procedure for Selected Assets with a PBI Rate of $0/kWh.

 

A-1

Exhibit A

Instructions

 

Number		Attribute		Instructions
				Do not perform this procedure for Selected Assets if Customer Agreement Seasoning (Months) in the Data File is greater than PBI Term.
11.		PBI Term (Years)		For Selected Assets with a State of “NJ” in the Data File for which PBI Rate ($/kWh) is not equal to $0/kWh use New Jersey’s Clean Energy’s website (listed below) to look up the PBI Term:   https://cleanenergy.nj.gov/programs/solar/administratively-determined-incentive-adi-program .   Do not perform this procedure for Selected Assets for which the Data File value or Source Document value is $0/kWh.   Do not perform this procedure for Selected Assets if Customer Agreement Seasoning (Months) in the Data File is greater than PBI Term.
12.		PTO Date		Consider the attribute to be in agreement if it is within 15 days of the Data File value.   Do not perform this procedure for Selected Assets for which PTO Date is not populated in the Data File.
13.		PPA Type (Balanced, Generation, Flex)		Do not perform this procedure for Selected Assets with a Contract Type of “Lease.”   For Selected Assets with a Total Monthly Payment Year 1 (Lease & Balanced PPAs) not equal to $0, consider the attribute to be in agreement if the Data File value is “Balanced.”
14.		Customer Agreement Remaining Initial Term (Months)		Recompute as the difference between Customer Agreement Term (Years) and Customer Agreement Seasoning (Months) in the Data File.

 

A-2

Exhibit B

The Selected Assets

 

Selected Asset Number		Customer Agreement ID		Selected Asset Number		Customer Agreement ID		Selected Asset Number		Customer Agreement ID
1		1922649***		41		3004313***		81		3003287***
2		1835671***		42		3004226***		82		3003855***
3		1019909***		43		2011788***		83		1372347***
4		1033685***		44		3003146***		84		1938850***
5		1084547***		45		3003101***		85		1934127***
6		1113473***		46		1615401***		86		1941258***
7		1206593***		47		1651762***		87		1982846***
8		3003619***		48		1596822***		88		3002870***
9		3002838***		49		1924720***		89		3001966***
10		3002649***		50		1695791***		90		2047925***
11		3003204***		51		3003169***		91		1475002***
12		1434492***		52		3002835***		92		1478365***
13		2037854***		53		3002747***		93		3003501***
14		1200560***		54		3003168***		94		1022647***
15		1216298***		55		3004120***		95		3004306***
16		1221791***		56		3004032***		96		3001820***
17		3004253***		57		1901677***		97		3004062***
18		1231911***		58		1710102***		98		2107713***
19		1249290***		59		1729382***		99		3003000***
20		1539634***		60		1091234***		100		3000058***
21		1265451***		61		1799246***		101		3004165***
22		1342958***		62		1563056***		102		1741908***
23		1781568***		63		2080198***		103		3001080***
24		1148327***		64		1820574***		104		3003300***
25		1373262***		65		1841159***		105		3003586***
26		2084412***		66		3003309***		106		1930175***
27		1326832***		67		1886548***		107		3001642***
28		3004065***		68		3003705***		108		3001796***
29		3002935***		69		1004493***		109		1693493***
30		3003638***		70		1913181***		110		3001820***
31		3002621***		71		1604330***		111		1287675***
32		1626778***		72		1766727***		112		3002144***
33		3002839***		73		3003031***		113		3002442***
34		1533327***		74		1914798***		114		3003345***
35		2081903***		75		3002857***		115		1448439***
36		1539236***		76		1916924***		116		3002670***
37		3001373***		77		3001813***		117		3003030***
38		1584058***		78		1929026***		118		2004444***
39		1047559***		79		3003296***		119		3004189***
40		1606196***		80		3002913***		120		3003171***

 

B-1

Exhibit B

The Selected Assets

 

Selected Asset Number		Customer Agreement ID		Selected Asset Number		Customer Agreement ID		Selected Asset Number		Customer Agreement ID
121		3002738***		161		3003286***		201		1401889***
122		3002767***		162		3003774***		202		2050487***
123		1662652***		163		3003503***		203		1350864***
124		2133704***		164		3003199***		204		3003276***
125		1915783***		165		1013393***		205		3003729***
126		3003855***		166		1427604***		206		3003501***
127		3003920***		167		1619209***		207		3002414***
128		3002952***		168		3002936***		208		3003348***
129		3003622***		169		1081195***		209		3003423***
130		3003735***		170		3003590***		210		3003314***
131		3002998***		171		3002957***		211		1392242***
132		1612653***		172		3002971***		212		3000640***
133		3003506***		173		1052364***		213		3002969***
134		1427613***		174		3003009***		214		1042315***
135		3002912***		175		3003045***		215		3003953***
136		3004289***		176		3003052***		216		3001982***
137		3002797***		177		3003075***		217		3003326***
138		3003032***		178		3003078***		218		3003355***
139		1485189***		179		1059288***		219		3003355***
140		3002817***		180		1731950***		220		3002126***
141		3002847***		181		3003627***		221		3004201***
142		3003330***		182		3003349***		222		3003774***
143		1644277***		183		1369050***		223		1855324***
144		3002735***		184		3002749***		224		1455892***
145		3003845***		185		1420185***		225		3003373***
146		1363478***		186		3000302***		226		3004206***
147		1750237***		187		3002989***		227		3003537***
148		2030612***		188		3004093***		228		2005106***
149		1699161***		189		3002849***		229		3002686***
150		1329993***		190		3003061***		230		3003490***
151		3002899***		191		3003087***		231		3004204***
152		2074379***		192		1600954***		232		3003182***
153		3004247***		193		3002232***		233		3004008***
154		3004018***		194		1125604***		234		3003913***
155		3002935***		195		3003165***		235		3002658***
156		1230878***		196		3002649***		236		3003669***
157		3004076***		197		3004195***		237		3003694***
158		3003344***		198		3003208***		238		1606890***
159		3003181***		199		1101010***		239		3003706***
160		3003788***		200		1034032***		240		2072337***

 

B-2

Exhibit B

The Selected Assets

 

Selected Asset Number		Customer Agreement ID		Selected Asset Number		Customer Agreement ID
241		3003801***		271		1120009***
242		3003559***		272		3004338***
243		3002892***		273		2063554***
244		3003139***		274		3003820***
245		3003981***		275		2065283***
246		1926092***		276		1502829***
247		3003815***		277		1100716***
248		1816712***		278		1001143***
249		1780472***		279		3004372***
250		3003033***		280		1167066***
251		1765058***		281		1209526***
252		3003796***		282		3003964***
253		3003340***		283		3003609***
254		3003686***		284		3003278***
255		3003843***		285		3004103***
256		3003194***		286		3003886***
257		3003621***		287		3002457***
258		3002505***		288		3003146***
259		3004041***		289		1962904***
260		1318643***		290		3004143***
261		1132552***		291		3004417***
262		3004055***		292		2050502***
263		1960493***		293		1388853***
264		1757806***		294		3004535***
265		1362237***		295		1728762***
266		3004086***		296		1255264***
267		3003240***		297		3003203***
268		3004250***		298		3003256***
269		3002516***		299		3002724***
270		3004296***		300		3002876***

 

B-3

Exhibit C

Exceptions

 

Selected Asset Number		Customer Agreement ID		Attribute		Per Data File		Per Provided Information
157		3004076***		Total Monthly Payment Year 1 (Lease & Balanced PPAs)		240.62		260.60
186		3000302***		PBI Term (Years)		6		20

 

C-1