A joint venture between bp and Iberdrola has entered the final construction phase of a 25MW green hydrogen facility in Castellón, with commissioning activities expected to begin later this year.
The project, developed through Castellón Green Hydrogen S.L., is designed to become the largest green hydrogen plant currently in operation in Spain once completed. The partners said the installation has reached about 90% completion of the assembly phase, while all major equipment has now been delivered to the site.
The plant’s electrolyser system has been supplied by Plug Power, and testing to assess equipment performance and operations is scheduled to start in May 2026.
The project represents an investment of more than €70 million, with both companies holding equal stakes through their joint venture. The electrolyser will be powered by renewable electricity supplied under a power purchase agreement using generation from Iberdrola’s solar and wind farms.
Once operational, the facility is expected to produce roughly 2,800 tonnes of green hydrogen annually. The hydrogen will replace part of the grey hydrogen currently used at bp’s refinery in Castellón, helping cut carbon emissions by an estimated 23,000 tonnes of CO₂ each year.
Carolina Mesa, vice president of hydrogen for Europe and MENA at bp, said the project marked progress for the country’s energy transition.
“These developments are great news for the Spanish energy sector,” Mesa said. “It reflects tangible progress in a key industrial decarbonisation project and consolidates the bp refinery in Castellón as a benchmark in the country.”
Julio Castro, chief executive of Iberdrola Energía Sostenible España, said the project highlights the role of electrification in reducing industrial emissions.
“This project is a real example of the electrification of industry, which reduces CO2 emissions and strengthens the security of energy supply,” Castro said. “This plant will be powered by 200 GWh/year of renewable energy from our wind farms and photovoltaic plants in Spain.”
