Wärtsilä Launches World's First Large-Scale 100% Hydrogen Engine Grid Verification

Technology group Wärtsilä has begun validating a brand-new 100% hydrogen-fueled engine, which is currently supplying power to the Spanish national grid from Bermeo, northern Spain. This marks the world's first large-scale 100% hydrogen engine demonstration project.

The trial represents a significant step forward in proving that engine technology can operate entirely on sustainable fuels such as hydrogen. Building on Wärtsilä's earlier launch of the world's first large-scale 100% hydrogen-ready engine power plant, the project charts a clear path toward fully renewable power systems. With global renewable energy capacity expected to grow by nearly 4,600 GW by 2030, flexible technologies that can maintain grid balance when wind and solar generation fall short are becoming increasingly critical.

Green hydrogen produces no carbon emissions during use, enabling not only clean power generation but also supporting the decarbonisation of grids dominated by renewables. Green hydrogen can store surplus renewable electricity and provide stable power when wind or photovoltaic output drops, thereby enhancing grid stability and supply reliability.

As a key component of the Wärtsilä 31 platform – one of the world's most efficient multi-fuel four-stroke engine platforms – the Wärtsilä 31H2 engine demonstrates that hydrogen has moved from theoretical research to practical energy infrastructure application. The Wärtsilä 31H2, currently the world's largest pure-hydrogen engine, is being validated in Bermeo.

Rasmus Teir, Director of Technology Strategy and Decarbonisation at Wärtsilä, said: "This is a trial for the future of renewable power generation. As countries rapidly scale up wind and solar capacity, one of the biggest challenges in the energy transition is how to sustainably ensure reliable power supply when renewable generation is insufficient or demand surges. Today, our Wärtsilä 31H2 engine is running on 100% hydrogen and supplying electricity to the Spanish national grid, proving that large hydrogen engines can deliver the flexible, dispatchable sustainable power needed in future renewable systems."

He added: "We have proven that the technology is ready for real-world application. The focus now is on creating the right environment for its scale-up, including clear regulatory policies, investment certainty, and the infrastructure to support the rapid growth of renewables and sustainable fuels like hydrogen. The technology is mature – now is the time to scale."

Power plants based on the Wärtsilä 31 platform are designed to provide flexible, sustainable power supply for fast-growing, energy-intensive industries, including:

● Data centres;

● Manufacturing facilities;

● Industrial parks;

● Off-grid applications.

As one of the world's leading countries in renewable energy deployment, Spain – with its continued reduction of dependence on fossil fuel price volatility – provides an ideal location for this trial and offers a strong testbed for demonstrating the future potential of hydrogen technology.

In June 2026, Wärtsilä customers from around the world witnessed the engine in operation on-site, marking an important milestone in its commercial validation.