Repsol installs its second 100 MW electrolyzer at Petronor

Madrid-based energy conglomerate Repsol has announced that it will install its second large-scale electrolyzer at its Petronor refinery near Bilbao in Northern Spain. Last September, the company approved the construction in Cartagena of its first large electrolyzer, with a capacity of 100 MW.

The new 100 MW electrolyzer 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 electrolyzer will have the capacity to produce up to 15,000 tons of renewable hydrogen per year, 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 decarbonization with a key contribution, as it will prevent the emission of up to 167,000 tons of CO₂ per year, equivalent to the emissions saved by two-thirds of the 100% electric vehicle fleet in Spain in 2024.

The project builds upon advances already achieved at Petronor in the development of renewable hydrogen: in 2023, its first electrolyzer, with a capacity of 2.5 MW, was put into operation. The 350 tons of renewable hydrogen produced annually 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 electrolyzer, 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 electrolyzer

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 electrolyzer of 100 MW, which will be installed at its Cartagena complex.