Repsol is making further progress in its industrial decarbonsation strategy through renewable hydrogen and will install its second large scale electrolyser at its Petronor refinery in Muskiz close to Bilbao in Northern Spain. In September 2025, the company approved the construction in Cartagena of its first large electrolyser, with a capacity of 100 MW.
The new 100 MW infrastructure will require an investment of €292 million for commissioning in 2029. Recognised by the European Commission as an Important Project of Common European Interest (IPCEI), it will have the support of the Government of Spain and will receive €160 million through NextGenerationEU funds from the Spanish Recovery, Transformation, and Resilience Plan.
The electrolyser will have the capacity to produce up to 15 000 tpy of renewable hydrogen, which will mainly be used in processes at the Petronor refinery itself. As part of the Basque Hydrogen Corridor, it will also supply renewable gas to the region’s industry, driving its decarbonisation with a key contribution, as it will prevent the emission of up to 167 000 tpy of CO2, equivalent to the emissions saved by two-thirds of the 100% electric vehicle fleet in Spain in 2024.
The project, which represents a first-class technological challenge due to its scale, will generate around 900 direct, indirect, and induced jobs throughout its different phases. In addition, it builds upon advances already achieved at Petronor in the development of renewable hydrogen: in 2023, its first electrolyser, with a capacity of 2.5 MW, was put into operation. The 350 tpy of renewable hydrogen produced already supply the refinery and the building where Petronor's offices are located, in the Technology Park of the town of Abanto Zierbena in the province of Bilbao.
Likewise, in 2024, construction began at the port of Bilbao of a second 10 MW electrolyser, which will supply the synthetic fuels demonstration plant that Repsol is building together with Aramco, and which is scheduled to start operations in 2026.
Second large electrolyser
Repsol leads hydrogen production and consumption in the Iberian Peninsula, concentrating 60% of national production and contributing 4% of European consumption. In September 2025, Repsol gave the green light to its first large electrolyser of 100 MW, which will be installed at its Cartagena complex.
The new renewable hydrogen plant will soon be joined by a large electrolyser in Tarragona, with a capacity of 150 MW. Like those atthe complexes in Cartagena and Petronor, it will mainly supply Repsol’s industrial complex. It is also expected to provide renewable hydrogen to the future Ecoplanta – which will produce renewable methanol from municipal waste – and to other local industries.