Name:	HTOO_AdditionOtherThanThroughBusinessCombinationsPropertyPlantAndEquipmentIncludingRightofuseAssets
Namespace Prefix:	HTOO_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Depreciation charge property plant and equipment.

No definition available.

Name:	HTOO_DepreciationChargePropertyPlantAndEquipment
Namespace Prefix:	HTOO_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Derecognition of property plant and equipment.

No definition available.

Name:	HTOO_DerecognitionOfPropertyPlantAndEquipment
Namespace Prefix:	HTOO_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Derecognition on deconsolidation.

No definition available.

Name:	HTOO_DerecognitionOnDeconsolidation
Namespace Prefix:	HTOO_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

Name:	HTOO_ScheduleOfPropertyPlantAndEquipmentsLineItem
Namespace Prefix:	HTOO_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of additions to property, plant and equipment including right-of-use assets other than those acquired through business combinations. [Refer: Total for all business combinations [member]; Property, plant and equipment including right-of-use assets]

Name:	ifrs-full_AdditionsOtherThanThroughBusinessCombinationsPropertyPlantAndEquipmentIncludingRightofuseAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 98
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_98_c&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_GainsLossesOnDisposalsOfPropertyPlantAndEquipment
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

Name:	ifrs-full_ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipmentIncludingRightofuseAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

The increase (decrease) in property, plant and equipment including right-of-use assets resulting from transfers. [Refer: Property, plant and equipment including right-of-use assets]

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of tangible assets that: (a) are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes; and (b) are expected to be used during more than one period. Note that right-of-use assets are not included. [Contrast: Property, plant and equipment including right-of-use assets]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2025-01-01
-Paragraph 73
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&anchor=para_73_e&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 200
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_200_e&doctype=Standard
-URIDate 2025-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 200
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_200_e&doctype=Standard
-URIDate 2025-03-27

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 54
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_54_a&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_PropertyPlantAndEquipment
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of property, plant and equipment including right-of-use assets whose underlying assets would be presented as property, plant and equipment if they were owned. [Refer: Property, plant and equipment; Right-of-use assets]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 16
-IssueDate 2025-01-01
-Paragraph 73
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2025-en-r&anchor=para_73_e&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 16
-IssueDate 2025-01-01
-Paragraph 47
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2025-en-r&anchor=para_47_a&doctype=Standard
-URIDate 2025-03-27

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 54
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_54_a&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_PropertyPlantAndEquipmentIncludingRightofuseAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The increase (decrease) in property, plant and equipment including right-of-use assets resulting from revaluations to fair value. [Refer: Property, plant and equipment including right-of-use assets; Revaluation surplus]

Name:	ifrs-full_RevaluationIncreaseDecreasePropertyPlantAndEquipmentIncludingRightofuseAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Name:	ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=HTOO_AssetsUnderConstructionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_MachineryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_OfficeEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_RightofuseAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis=ifrs-full_GrossCarryingAmountMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: