A large-scale hydrogen-powered engine has been successfully tested at a facility in northern Spain, with the system supplying electricity to the Spanish national grid during a controlled demonstration, according to Finnish energy technology company Wärtsilä.
The trial, conducted at the company’s Bermeo laboratory, represents what Wärtsilä describes as the world’s first operation of a large-scale engine running on 100% hydrogen under grid-connected conditions. The company said the demonstration forms part of a broader validation process for hydrogen-based power generation technology.
Hydrogen Engine Technology enters Grid-Linked Testing Phase
The system is based on the Wärtsilä 31H2 engine, a hydrogen-fueled variant of the company’s multi-fuel engine platform. Unlike hydrogen fuel cells, the technology uses an internal combustion engine adapted to operate on pure hydrogen.
Wärtsilä said the test demonstrates that engine-based systems can operate on 100% hydrogen while producing electricity for real-world grid conditions, moving beyond earlier hydrogen-ready configurations that required multiple fuel types.
Rasmus Teir, Director of Technology Strategy & Decarbonisation at Wärtsilä, said: “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.”
Role in Renewable Energy Balancing
The company positions hydrogen engines as a potential solution for balancing electricity systems with high shares of wind and solar generation. Hydrogen can be produced using surplus renewable electricity and later used to generate power when output from renewables declines.
Wärtsilä said such systems could provide dispatchable electricity to stabilize grids and support decarbonization goals, particularly as renewable capacity expands globally.
Scale-Up Plans and Industrial Applications
Wärtsilä stated that multiple hydrogen-fueled engines could eventually be deployed together in utility-scale configurations capable of producing hundreds of megawatts of electricity.
Beyond grid support, the company also sees potential applications in energy-intensive sectors, including data centers, manufacturing, and industrial facilities requiring flexible power supply.
“The technology is here – now it’s time to scale it,” Teir said, adding that regulatory clarity, infrastructure development, and investment frameworks will be essential for broader deployment.
Infrastructure Challenges and Deployment Outlook
Despite the successful demonstration, large-scale adoption of hydrogen power generation faces significant challenges. These include the development of hydrogen production capacity, storage systems, and transport infrastructure, as well as supportive regulatory and policy frameworks.
Analysts note that while hydrogen offers potential for low-carbon dispatchable power, its scalability will depend on cost reductions and coordinated investment across the energy supply chain.
Spain as a Renewable Energy Test Environment
Spain has emerged as a key testing environment for renewable and low-carbon energy technologies due to its expanding wind and solar generation capacity and broader energy transition strategy.
The country continues to increase the share of renewables in its electricity mix, creating conditions where flexible backup generation technologies such as hydrogen engines could play a supporting role.
In June 2026, international customers observed the hydrogen engine’s operation during its validation phase in Bermeo, marking a milestone in its technical and commercial assessment.