The technology group Wärtsilä and WEC Energy Group have successfully tested the capabilities of a Wärtsilä engine running on 25-vol% H₂-blended fuel. The tests, which were completed in October 2022, were conducted at WEC Energy Group’s 55 MW A.J. Mihm power plant in Michigan, U.S. using an unmodified Wärtsilä 50SG engine. Throughout the testing period, the Wärtsilä engine continued to supply power to the grid.

The Electric Power Research Institute (EPRI) also participated in the tests and led the assessment of the engine’s performance during the testing. In a recently released report, EPRI’s analysis confirmed the feasibility of blending H₂ with natural gas for use in an existing Wärtsilä engine. The demonstration results also showed H₂ can be safely and reliably handled and utilized in engine technology.  

During three days of continuous testing, the capability of the engine to co-fire H₂ blends was successfully demonstrated, showing clear improvements in engine efficiency and reduced greenhouse gas emissions, while staying compliant with NOx emissions. A 95% engine load was achieved with the 25-vol% H₂ blend. This verifies the fuel flexibility of Wärtsilä engines without compromising efficiency. Further testing showed that with a 17-vol% H₂ blend, a 100% engine load was attainable.

The EPRI report states that this class of engines can therefore maintain its higher efficiency compared to simple-cycle gas turbines. Because engines in general have higher efficiency, their relative CO₂ output compared to turbines will also be lower, as was the case in this study.

“These tests provide clear evidence that Wärtsilä’s engine technology can deliver future-proof power solutions that make a huge contribution towards decarbonized operations. The results of the testing with a H₂/natural gas blended fuel mix have been outstanding. We continue developing and futureproofing our engines to run on sustainable fuels and expect to have an engine and power plant concept for operating with pure H₂ available by 2026,” said Anja Frada, Chief Operating Officer, Wärtsilä Energy.

“EPRI is accelerating deployment of a full portfolio of clean energy technologies to support a net-zero future,” said EPRI Vice President of Energy Supply and Low-Carbon Resources Neva Espinoza. “This demonstration project with Wärtsilä and WEC Energy Group is significant in showing the potential of H₂ blending in natural gas-fired engines. The learnings from this project will be shared with the energy industry to further progress toward deep decarbonization targets.”

As utilities increase the utilization of renewable energy assets, such as wind and solar, opportunities exist to produce H₂ for long-term energy storage from excess renewable energy. As a fuel, H₂ burns without producing any carbon species including CO₂. H₂ electrolyzer manufacturing capacity sits at nearly 8 GW/yr today, but it could exceed 60GW/yr by 2030 based on industry announcements.

“We’re very pleased to take a leading role exploring the potential of this technology as we focus on providing customers with affordable, reliable and clean energy,” said Gale Klappa, executive chairman — WEC Energy Group. “As we bring more renewable energy online, we must ensure that we can keep the lights on when the sun is not shining, and the wind is not blowing. The results of this project are a strong indicator that these dispatchable units can run on very low- and no-carbon fuels.”