Repsol installs its second large 100 MW electrolyzer at Petronor

Repsol is advancing its industrial decarbonization agenda through renewable hydrogen with plans to install a second large-scale electrolyzer at its Petronor refinery in Muskiz, Biscay. This follows the company’s approval in September of last year for its first major electrolyzer project—a 100-MW unit at the Cartagena refinery.

The new 100-MW facility in Muskiz will require an investment of €292 million and is scheduled to come online in 2029. Designated by the European Commission as an Important Project of Common European Interest (IPCEI), the project is backed by the Spanish government and will receive €160 million in funding from the NextGenerationEU program under the Recovery, Transformation and Resilience Plan.

Once operational, the electrolyzer will be capable of producing up to 15,000 tonnes of renewable hydrogen per year, primarily for use in Petronor’s refinery operations. As part of the Basque Hydrogen Corridor, it will also supply renewable hydrogen to regional industries, supporting their decarbonization efforts. The project is expected to avoid up to 167,000 tonnes of CO₂ emissions annually—an amount comparable to roughly two-thirds of Spain’s fully electric vehicle fleet in 2024.

Given its scale, the initiative represents a significant technological undertaking and is projected to create around 900 direct, indirect, and induced jobs across its development phases.

This project builds on Petronor’s earlier achievements in renewable hydrogen. In 2023, the company commissioned a 2.5-MW electrolyzer producing around 350 tonnes of renewable hydrogen annually, supplying both the refinery and Petronor’s office facilities at the Abanto Zierbena Technology Park in Biscay. In addition, construction began in 2024 at the Port of Bilbao on a second 10-MW electrolyzer, expected to be commissioned in 2026, which will supply a synthetic fuels demonstration plant jointly developed by Repsol and Aramco.