v3.26.1
Intangible assets (Details) - USD ($)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year $ 103,095,000  
Other intangible assets at end of the year 132,682,000 $ 103,095,000
Acquisition cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 212,392,000 250,707,000
Additions 91,203,000 63,740,000
Disposals (117,056,000) (90,112,000)
Transfers from/(to) other accounts 542,000  
Exchange differences 19,917,000 (11,943,000)
Other intangible assets at end of the year 206,998,000 212,392,000
Accumulated Amortization    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year (94,070,000) (96,086,000)
Disposals 34,470,000  
Transfers from/(to) other accounts 21,000  
Depreciation and amortization for the period (1,916,000) (474,000)
Exchange differences (5,201,000) 2,490,000
Other intangible assets at end of the year (66,696,000) (94,070,000)
Impairment    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year (15,227,000) (16,276,000)
Disposals 9,413,000  
Exchange differences (1,806,000) 1,049,000
Other intangible assets at end of the year (7,620,000) (15,227,000)
Development Expenditure    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 3,789,000  
Other intangible assets at end of the year 5,147,000 3,789,000
Development Expenditure | Acquisition cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 51,221,000 53,590,000
Additions 972,000 664,000
Disposals (40,317,000)  
Transfers from/(to) other accounts 542,000 328,000
Exchange differences 6,573,000 (3,361,000)
Other intangible assets at end of the year 18,991,000 51,221,000
Development Expenditure | Accumulated Amortization    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year (34,424,000) (36,353,000)
Disposals 32,148,000  
Transfers from/(to) other accounts 15,000  
Depreciation and amortization for the period (706,000) (229,000)
Exchange differences (4,366,000) 2,158,000
Other intangible assets at end of the year (7,333,000) (34,424,000)
Development Expenditure | Impairment    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year (13,008,000) (13,991,000)
Disposals 8,169,000  
Exchange differences (1,672,000) 983,000
Other intangible assets at end of the year (6,511,000) (13,008,000)
Power Supply Agreements | Acquisition cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 37,836,000 37,836,000
Other intangible assets at end of the year 37,836,000 37,836,000
Power Supply Agreements | Accumulated Amortization    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year (37,836,000) (37,836,000)
Other intangible assets at end of the year (37,836,000) (37,836,000)
Rights of Use | Acquisition cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 13,105,000 13,329,000
Transfers from/(to) other accounts   (31,000)
Exchange differences 315,000 (193,000)
Other intangible assets at end of the year 13,420,000 13,105,000
Rights of Use | Accumulated Amortization    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year (11,996,000) (12,142,000)
Exchange differences (315,000) 146,000
Other intangible assets at end of the year (12,311,000) (11,996,000)
Rights of Use | Impairment    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year (1,109,000) (1,187,000)
Exchange differences   78,000
Other intangible assets at end of the year (1,109,000) (1,109,000)
Computer Software    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 7,743,000  
Other intangible assets at end of the year 8,607,000 7,743,000
Computer Software | Acquisition cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 12,757,000 10,396,000
Additions 1,209,000 2,750,000
Disposals (196,000)  
Exchange differences 1,147,000 (389,000)
Other intangible assets at end of the year 14,917,000 12,757,000
Computer Software | Accumulated Amortization    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year (5,014,000) (5,076,000)
Disposals 73,000  
Depreciation and amortization for the period (1,210,000) (27,000)
Exchange differences (159,000) 89,000
Other intangible assets at end of the year (6,310,000) (5,014,000)
Greenhouse Gasses (CO2) [member]    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 90,563,000  
Other intangible assets at end of the year 117,783,000 90,563,000
Greenhouse Gasses (CO2) [member] | Acquisition cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 90,563,000 128,176,000
Additions 89,022,000 60,326,000
Disposals (73,050,000) (90,112,000)
Exchange differences 11,248,000 (7,827,000)
Other intangible assets at end of the year 117,783,000 90,563,000
Other Intangible Assets    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 1,000,000  
Other intangible assets at end of the year 1,145,000 1,000,000
Other Intangible Assets | Acquisition cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year 6,910,000 7,380,000
Disposals (3,493,000)  
Transfers from/(to) other accounts   (297,000)
Exchange differences 634,000 (173,000)
Other intangible assets at end of the year 4,051,000 6,910,000
Other Intangible Assets | Accumulated Amortization    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year (4,800,000) (4,679,000)
Disposals 2,249,000  
Transfers from/(to) other accounts 6,000  
Depreciation and amortization for the period   (218,000)
Exchange differences (361,000) 97,000
Other intangible assets at end of the year (2,906,000) (4,800,000)
Other Intangible Assets | Impairment    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Other intangible assets at beginning of the year (1,110,000) (1,098,000)
Disposals 1,244,000  
Exchange differences $ (134,000) (12,000)
Other intangible assets at end of the year   $ (1,110,000)