Wärtsilä runs world’s first 100% hydrogen engine feeding Spain’s grid

Wärtsilä’s 31H2 engine – a 13‑cylinder unit the size of a shipping container – operated for several days on pure hydrogen and supplied electricity directly to Spain’s national grid in Bermeo, the Basque coast. The trial, announced on 11 June, marks the first time a large‑scale internal‑combustion engine has run on 100 % hydrogen under real‑world grid conditions, proving the hardware can work beyond laboratory testing.

The Finnish group says the test demonstrates that hydrogen‑fired power generation can provide fast, dispatchable backup for grids increasingly powered by wind and solar. Rasmus Teir, Wärtsilä’s director of technology strategy and decarbonisation, called it “a trial for the future of renewable power.” The company notes that affordable green hydrogen and the required supply infrastructure remain challenges, but the engine is designed for use in industrial sites, data centres and off‑grid locations that need reliable, zero‑carbon electricity.

The demonstration supports Wärtsilä’s push to scale hydrogen technology as part of the global shift toward renewable energy and grid stability.