World’s first large-scale 100% hydrogen engine tested at Wärtsilä’s Bermeo laboratory to support the Spanish grid

Wärtsilä Corporation, Press release, 11 June 2026 at 05:00 AM EEST

• Wärtsilä Energy has successfully operated a new 100% hydrogen engine supplying power to Spain’s national electricity grid in Bermeo, Spain. This is the world’s first demonstration of a large-scale hydrogen engine running on 100% pure hydrogen.
• The demonstration marks a significant step beyond hydrogen-ready technologies, proving that engine-based power generation can run entirely on hydrogen in real grid conditions – paving the way for this capability to become a reality at scale in the future.
• Hydrogen-fuelled Wärtsilä 31 engines can also support energy-intensive sectors, such as AI data centres and industry in the future.

Technology group Wärtsilä has started validation of a new 100% hydrogen engine to power Spain’s national electricity grid in Bermeo, northern Spain – the world’s first demonstration of a large-scale, 100% hydrogen engine.

The trial marks a major step forward in proving that engine technology can operate on 100% sustainable fuels such as hydrogen, building on Wärtsilä’s earlier launch of the world’s first large-scale 100% hydrogen-ready engine power plant and opening a clear pathway towards fully renewable power systems. With global renewable energy generation set to grow by almost 4,600 GW by 2030, flexible technologies capable of balancing grids during periods of low wind and solar output are becoming increasingly critical.

Green hydrogen produces no carbon emissions, enabling clean power generation while supporting the decarbonisation of renewable-heavy grids. It can store excess renewable electricity and provide reliable power when wind or solar generation drops, helping to stabilise the system and improve energy reliability.

The Wärtsilä 31H2 engine, part of the Wärtsilä 31 platform, one of the world’s most efficient multi-fuel 4-stroke engines, shows that hydrogen can move beyond theory into real-world energy infrastructure. The Wärtsilä 31H2 engine is the world’s largest pure hydrogen engine, with performance currently being verified in Bermeo.

Rasmus Teir, Director of Technology Strategy & Decarbonisation at Wärtsilä, says: “This is a trial for the future of renewable power. As countries rapidly scale wind and solar energy, one of the biggest challenges facing the energy transition is how to maintain reliable electricity supplies sustainably during periods of low renewable generation or spikes in demand. Today, our Wärtsilä 31H2 hydrogen engine is operating on 100% hydrogen and supplying power to Spain’s national grid, demonstrating that large-scale hydrogen engines can provide the flexible, dispatchable sustainable power needed to support future renewable energy systems.”

“We have proven the technology is ready. Now, the focus must be on creating the right environment to scale it, underpinned by decisive regulation, investment clarity, and the infrastructure needed to accelerate the growth of renewable energy and sustainable fuels like hydrogen. The technology is here – now it’s time to scale it.” 

The Wärtsilä 31 based power plant is designed to support rapidly growing, energy-intensive industries – including data centres, manufacturing facilities and industry – with flexible, sustainable power generation, and off-grid environments.

Spain, as one of the forerunners in renewable energy adaption, provided an ideal location for the trial thanks to its efforts to reduce exposure to fossil fuel volatility, making it a strong test bed for demonstrating the future potential of hydrogen technologies.

In June 2026, Wärtsilä’s customers from around the world witnessed the operation of the engine, marking a significant milestone in its commercial validation.

Media contact:

Katri Pehkonen 
Communications Manager 
Wärtsilä Energy 
Mob: +358 50 591 6180 
katri.pehkonen@wartsila.com

Contact for product related inquiries: 

Christian Hultholm
Product Manager, W31 Power Plants
Wärtsilä Energy
Mob: +358 40 194 9579 
christian.hultholm@wartsila.com

Media kit including key materials

Image caption: Wärtsilä has started validation of a new 100% hydrogen engine to power Spain’s national electricity grid in Bermeo, northern Spain – the world’s first demonstration of a large-scale, 100% hydrogen engine. © Wärtsilä Corporation

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About Wärtsilä Energy 
Wärtsilä Energy is at the forefront of the transition towards a 100% renewable energy future. We help our customers and the power sector to accelerate their decarbonisation journeys through our market-leading technologies and power system expertise. Our solutions include flexible engine power plants, energy storage and optimisation technology, and services for the whole lifecycle of our installations. Our engines are future-proof and can run on sustainable fuels. Our track record comprises 81 GW of power plant capacity and over 130 energy storage installations in 180 countries around the world. About 35% of our operating installed base is under service agreements. 
www.wartsila.com/energy

Wärtsilä in brief 
Wärtsilä is a global leader in innovative technologies and lifecycle solutions for the marine and energy industries. We emphasise innovation in sustainable technology and services to help our customers continuously improve environmental and economic performance. Our dedicated and passionate team of 17,900 professionals in 199 locations in 78 countries shape the decarbonisation transformation of our industries across the globe. In 2025, Wärtsilä’s net sales totalled EUR 6.9 billion. Wärtsilä is listed on Nasdaq Helsinki. 
www.wartsila.com