Related Parties (Details) - EUR (€) € in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Related Parties
Basic salary	€ 1,471	€ 683	€ 135
Short-term employee benefits	498	5
Other long-term benefits	80	3
Share-based compensation	2,957	183	1,066
Total	€ 5,006	€ 874	€ 1,201

No definition available.

Name:	htoo_BasicSalary
Namespace Prefix:	htoo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	htoo_RelatedPartiesAbstract
Namespace Prefix:	htoo_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	htoo_TotalAmountOfExpense
Namespace Prefix:	htoo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Adjustments for share-based payments to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2022-03-24
-Paragraph 20
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2022-en-r&anchor=para_20_b&doctype=Standard
-URIDate 2022-03-24

+ Details

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

- Definition

The amount of long-term employee benefits other than post-employment benefits and termination benefits. Such benefits may include long-term paid absences, jubilee or other long-service benefits, long-term disability benefits, long-term profit-sharing and bonuses and long-term deferred remuneration. [Refer: Employee benefits expense]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2022-03-24
-Paragraph 158
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2022-en-r&anchor=para_158&doctype=Standard
-URIDate 2022-03-24

+ Details

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

- Definition

The amount of expense from employee benefits (other than termination benefits) that are expected to be settled wholly within twelve months after the end of the annual reporting period in which the employees render the related services.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2022-03-24
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2022-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2022-03-24

+ Details

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