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. This comes at a time when countries such as India are accelerating investments in green hydrogen and renewable energy as part of their long-term decarbonisation strategies.
For India, this milestone is particularly significant as the country targets 500 GW of non-fossil fuel electricity capacity by 2030 and advances the National Green Hydrogen Mission to establish itself as a global hub for the production, utilisation, and export of green hydrogen. As renewable energy penetration increases, hydrogen-capable engine technologies can provide the flexible, dispatchable power needed to maintain grid stability while enabling greater integration of renewable energy at scale.
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.
Today, Wärtsilä’s engines can already operate on natural gas blended with up to 25 vol% hydrogen, a capability increasingly reflected in power generation tenders, including in India. This was demonstrated in 2022, when Wärtsilä and WEC Energy Group ran an unmodified Wärtsilä 50SG engine on a 25 vol% hydrogen blend at the 55 MW A.J. Mihm power plant in Michigan, USA. The Wärtsilä 31H2 engine builds on this foundation, marking the next step in the evolution towards a large-scale power plant running entirely on 100% hydrogen.
R. Venkatesh, Managing Director, Wärtsilä India, said: “India is entering a defining decade in its energy transition. With the government’s strong focus on renewable energy expansion and the National Green Hydrogen Mission, technologies that complement renewable generation while strengthening grid reliability will become increasingly important. Wärtsilä’s demonstration of a large-scale engine operating on 100% hydrogen reinforces our commitment to supporting India’s transition towards a cleaner, more resilient, and future-ready, low-carbon energy ecosystem.”
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.
India is witnessing rapid growth in digital infrastructure, advanced manufacturing, and industrial production, all of which are driving higher demand for reliable, flexible, and sustainable sources of electricity. As AI-led data centre investments continue to accelerate across the country, technologies capable of delivering dispatchable low-carbon power will become increasingly valuable in supporting future energy demand.
While the validation is being undertaken in Spain, the learnings from the demonstration will help advance Wärtsilä’s hydrogen roadmap globally, including in markets such as India, where renewable energy expansion and investments in green hydrogen are creating new opportunities for flexible, low-carbon power generation.





