Wärtsilä hydrogen engine delivers electricity to Spain's grid

Wärtsilä Energy operated its 31H2 engine – the world’s first large‑scale internal‑combustion engine running on 100 % pure hydrogen – at its testing facility in Bermeo, northern Spain. The engine supplied power directly to Spain’s national electricity grid, marking a milestone for flexible, low‑carbon generation that can balance intermittent wind and solar output.

Company officials say the technology could be scaled by linking multiple units into utility‑size plants capable of producing hundreds of megawatts, offering dispatchable, zero‑emission power for grids and energy‑intensive users. Rasmus Teir, Wärtsilä’s Director of Technology Strategy and Decarbonisation, called the trial “a trial for the future of renewable power.”

Experts caution that widespread adoption will require substantial investment in hydrogen production, storage and transport infrastructure, as well as supportive policy frameworks. The demonstration coincided with Spain’s rapid expansion of renewable capacity, highlighting hydrogen’s potential role in the country’s decarbonisation strategy.