Wärtsilä Demonstrates World's First Large-Scale Engine Running on 100 Percent Hydrogen in Live Grid Operation
Helsinki – Finnish technology group Wärtsilä has for the first time operated a large-scale engine on 100 percent hydrogen in Bermeo, northern Spain, feeding electricity directly into the public grid. According to the company, this marks the first time anywhere in the world that large-scale combustion engine technology has been tested on a fully hydrogen basis under real grid conditions.
Large-Scale Hydrogen Engine Based on the Wärtsilä 31 Platform
The 31H2 engine under test is based on the established Wärtsilä 31 platform, which the company says is deployed in power plant applications worldwide and is regarded as one of the most efficient multi-fuel engine platforms available. The new variant is designed for operation on pure hydrogen and is currently being validated under real grid conditions.
"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," said Rasmus Teir, Director of Technology Strategy & Decarbonisation at Wärtsilä.
A Flexibility Option for Wind- and Solar-Dominated Power Systems
As wind and solar capacity continues to expand, the need for fast-ramping generation capacity to safeguard security of supply amid variable feed-in is growing. Hydrogen engines are being positioned as a potential option for flexible backup and peaking power in the electricity system.
Wärtsilä also sees future applications for the technology in energy-intensive sectors such as industry, data centers and decentralized energy supply systems.
Scaling Hydrogen Power Plants in Step With Hydrogen Supply
The demonstration comes at a time when the buildout of hydrogen infrastructure and the availability of green hydrogen are widely regarded as key factors for broad market adoption. Central to scaling the technology will be how quickly hydrogen can establish itself as a tradable and readily available energy carrier – and how well that development can be synchronized with the expansion of renewable generation capacity.
Rasmus Teir: "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."
Source: IWR Online, 25 Jun 2026
