Repsol will install its second 100MW renewable hydrogen electrolyser at the Petronor industrial complex in Muskiz near Bilbao in northern Spain.
The project will require an investment of €292 million and is scheduled for commissioning in 2029, the company said.
It has been recognised by the European Commission as an Important Project of Common European Interest and will receive €160 million in support through NextGenerationEU funds from Spain’s recovery plan, according to Repsol.
The electrolyser will be capable of producing up to 15,000 tonnes of renewable hydrogen per year, mainly for use at the Petronor refinery.
Repsol said the facility will also supply renewable hydrogen to regional industry as part of the Basque Hydrogen Corridor.
The company said the project will help prevent up to 167,000 tonnes of CO2 emissions annually through industrial decarbonisation.
Repsol said the electrolyser represents a major technological challenge and is expected to generate around 900 direct, indirect and induced jobs.
The Bilbao project builds on earlier hydrogen developments at Petronor, including a 2.5MW electrolyser that began operating in 2023.
Repsol added that a 10MW electrolyser under construction at the port of Bilbao is due to start operations in 2026 to supply a synthetic fuels demonstration plant.
The company said it approved its first large-scale 100MW electrolyser at its Cartagena complex in September 2025.
Repsol added that a further 150MW electrolyser is planned at its Tarragona complex to supply its own operations and other local industries.