The world’s first large-scale engine powered exclusively by hydrogen has supplied electricity to the national power grid.
Wärtsilä Tests World’s First Large-Scale 100% Hydrogen-Powered Engine in Spain
In the Wärtsilä laboratory in Bermeo, Spain, testing is underway on a technology that could play an important role in stabilizing power systems based on renewable energy sources. The company has launched the world’s first large-scale engine powered entirely by 100% hydrogen, delivering electricity directly to Spain’s national grid.
This marks the first real-world case of a large power engine operating exclusively on clean hydrogen under actual grid conditions. The demonstration goes beyond the concept of “hydrogen-ready” technology and shows that hydrogen can already function as a fully operational fuel for flexible power sources supporting the energy transition.
Hydrogen as a Solution to Renewable Energy Instability
The growing share of wind and solar power introduces new challenges for grid operators. During periods of low renewable generation, stable electricity supply must still be maintained. According to forecasts, global renewable capacity will increase by nearly 4,600 GW by 2030, further increasing the need for flexible balancing resources.
In this context, green hydrogen is seen as a key component of the future energy mix. It can store surplus energy generated by wind farms and solar installations and later be used to produce electricity when demand rises or renewable output drops.
Unlike fossil fuels, green hydrogen use does not generate carbon dioxide emissions, allowing energy security to be combined with decarbonization goals.
The World’s Largest Pure Hydrogen Engine
The engine tested in Bermeo, the Wärtsilä 31H2, is based on the Wärtsilä 31 platform, considered one of the most efficient multi-fuel four-stroke engine platforms in the world.
According to the manufacturer, it is currently the largest power engine operating exclusively on hydrogen. Ongoing tests aim to confirm its performance parameters and readiness for commercial deployment in the energy sector.
“This is a test of the future of renewable energy. As countries rapidly scale up wind and solar power, one of the biggest challenges is ensuring reliable electricity supply in a sustainable way. Today our Wärtsilä 31H2 engine runs 100% on hydrogen and delivers power to the Spanish grid, demonstrating that large-scale hydrogen engines can provide the flexible and dispatchable capacity needed for future energy systems,” said Rasmus Teir, Director of Technology Strategy and Decarbonization at Wärtsilä.
He added that the technology is already ready for deployment, but wider adoption will require appropriate regulations, investment, and expansion of hydrogen infrastructure.
Beyond Energy: Hydrogen for AI Data Centers
Potential applications extend beyond traditional power generation. Wärtsilä notes that engines based on the 31 platform could also support rapidly growing energy-intensive sectors such as artificial intelligence data centers, industrial facilities, and off-grid autonomous energy systems.
This is particularly important given the rising electricity demand driven by AI and digitalization. Data center operators are increasingly looking for zero-emission, stable energy sources to replace traditional diesel generators.
Spain as a Testing Ground for the Hydrogen Economy
Spain is a natural location for this demonstration. The country is a European leader in renewable energy development and is heavily investing in green hydrogen projects.
Thanks to its strong wind and solar resources, Spain has significant potential to produce green hydrogen, which could become both a pillar of energy security and an export product for the European economy.
In June 2026, Wärtsilä customers from around the world observed the engine in operation. For the industry, it was a clear signal that hydrogen technologies are moving into the next stage of development—from laboratory demonstrations to real-world deployment in power systems.