For Worldwide Release: June 24, 2025

IRVING, TEXAS—Caterpillar Inc. today announced the results of a fuel flexibility project with District Energy St. Paul that successfully demonstrated a 2.0 MW combined heat and power (CHP) system with a Cat® G3516 gas generator set using 100% hydrogen fuel. The CHP system demonstrated maximum efficiency consistent with high-performance generator sets operating entirely on natural gas.

Supported and partially funded by the U.S. Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy (EERE) under the Industrial Efficiency and Decarbonization Office (IEDO), the project was led by Caterpillar in collaboration with District Energy St. Paul and DOE’s National Renewable Energy Laboratory (NREL).

The project’s objective was to evaluate the solution’s impact on local air quality and highlight the reliability and durability of a hydrogen system. To fully assess every aspect of the hydrogen system under real-world operating conditions, power and heat from the demonstration project were fed into the Minnesota utility’s active distribution system. The system used 100% hydrogen fuel and 100% natural gas fuel for up to 200 hours with each fuel type.

“As technology in our industry continues to advance, we will need a range of fuels and energy sources to capture the optimal function and efficiencies of these energy systems,” said Luke Gaalswyk, president and CEO of District Energy St. Paul. “It has been exciting for our team to help advance the data on hydrogen use with a global leader like Caterpillar in partnership with the DOE and NREL.”

“The success of this CHP demonstration highlights our commitment to understanding our customers’ needs and delivering tailored energy solutions that help them achieve their energy goals,” said Melissa Busen, senior vice president for Caterpillar’s Electric Power Division. “This is a great example of our expertise and commitment to developing innovative solutions that help build a better, more sustainable world.”

District Energy St. Paul’s Commitment to Environmental Stewardship 

District Energy St. Paul is a recognized leader in environmental and energy sustainability, earning a Global Sustainability award from the International Energy Agency and recognition from the United Nations Environment Programme. 

District Energy St. Paul is committed to carbon neutrality by 2050 and has already made notable progress on carbon reduction targets over the years. The integration of renewable energy through CHP solutions using solar thermal and biomass has helped the system achieve nearly 50% renewable heat and reduced the system’s greenhouse gas emissions by 77% over two decades. These achievements were made possible in part through increased efficiency, enhanced customer building performance, improved data and controls management, and upgraded production with higher efficiency equipment.

Expanding Leadership in Hydrogen-Fueled Power Solutions 

Caterpillar offers power solutions that help enterprises achieve their energy needs and sustainability initiatives. In addition to the G3516 fuel-flexible generator set used by District Energy St. Paul, Caterpillar’s hydrogen-fuel power technologies currently include a range of commercially available generator sets from 400 kW to 4.5 MW configured to operate on natural gas blended with up to 25% hydrogen by volume through factory-installed hardware and retrofit kits.

These solutions build on Caterpillar’s 35 years of enterprise experience in hydrogen fuels that support numerous power generation projects across multiple end industries, including gas turbines currently operating on natural gas blended with up to 80% hydrogen by volume. 

For more information, visit cat.com/hydrogen.

Acknowledgement: This announcement is based upon work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Industrial Efficiency and Decarbonization Office (IEDO), Award Number DEEE0009422.  The views expressed herein do not necessarily represent the views of the U.S. Department of Energy or the United States Government.