Repsol announced it is installing a second 100MW renewable hydrogen electrolyzer at the Petronor refinery operated by its subsidiary Petronor, located in Muskiz near Bilbao, Spain. The electrolyzer is capable of producing up to 15,000 tonnes of renewable hydrogen annually, has been recognized as an Important Project of Common European Interest (IPCEI) by the European Union, and is targeting startup in 2029.
The project is a large-scale electrolysis facility being pursued by Repsol and Petronor, linked to the Basque Hydrogen Corridor promoted by the Spanish government. The 100MW electrolyzer, the second to be installed at the Petronor refinery, aims to replace hydrogen used in refining processes with green hydrogen produced from renewable electricity.
The electrolyzer has a capacity of 100MW, with annual renewable hydrogen production expected to reach up to 15,000 tonnes. Total investment is €292 million, of which €160 million is supported by funding from Spain’s Recovery, Transformation and Resilience Plan (RTRP), financed through the EU’s NextGenerationEU program. The project is expected to reduce carbon dioxide emissions by up to 167,000 tonnes annually and to create approximately 900 direct and indirect jobs.
The electrolyzer is one of the flagship green hydrogen projects recognized as an EU-designated Important Project of Common European Interest, receiving support at the member-state level, and is regarded as a case where Spain’s refining industry decarbonization strategy intersects with the EU’s hydrogen economy promotion policy. The Basque region where the Petronor refinery is located is also an area the Spanish government is developing as an industrial cluster linking green hydrogen production and demand.
European refiners have, in recent years, pursued a series of projects replacing refinery hydrogen sourced from conventional fossil fuels with green hydrogen produced from renewable electricity, and this second Petronor electrolyzer extends that trend. The fact that a 100MW electrolyzer is being installed for the second time at the same refinery site indicates that a phased approach to expanding capacity, rather than a single large investment, is being adopted in actual refinery decarbonization projects. The EU’s financial support covering more than half of the total investment suggests that large-scale green hydrogen projects still find it difficult to achieve commercial viability on their own and remain substantially dependent on policy support. For electrolyzer equipment suppliers and related engineering firms, the continuation of refinery-linked green hydrogen projects across Europe is expected to generate ongoing order opportunities. In addition, the approach of sequentially adding electrolyzers at the same site allows operating experience from the first unit to be reflected in the design and operational efficiency of subsequent units, illustrating a learning-curve effect at work in large-scale green hydrogen projects.
The permitting procedures and the actual disbursement schedule of EU and Spanish government funding that remain before the 2029 startup target are the primary points to watch. How other demand-side and supply chain projects linked to the Basque Hydrogen Corridor will progress in tandem with this electrolyzer’s startup timeline is also worth watching. In addition, whether the Petronor refinery’s total renewable hydrogen production capacity, combining the first and this second electrolyzer, will be further expanded going forward is also of interest. Whether the renewable hydrogen produced will be supplied beyond the refinery’s own process demand to other users, such as nearby industrial parks or the mobility sector, also remains to be confirmed.