For more than a century, Cleveland Thermal has produced and delivered district energy—centralized steam and chilled water—for downtown Cleveland buildings and campuses. Its Hamilton Avenue Plant and underground network serve 20 million square feet, supplying about 30% of downtown’s heating and cooling needs with reported 99.9% reliability. After switching from coal to natural gas in 2017, the system cut CO2 and greenhouse-gas emissions by 84%.
Clean Heat TechnologiesClean Heat Technologies grew out of Lalit Chordia’s supercritical-CO2 work, begun with his first company in 1990, and now brings more than 30 years of research to commercial heat-pump development. The Pittsburgh company is known for establishing a commercial-scale direct-exchange geothermal system using CO2 and designs systems for customers seeking lower-energy heating or cooling in buildings and industrial operations.PITTSBURGH, PA
CEMLINE CORPSince 1935, CEMLINE Corporation has manufactured tanks, pressure vessels, packaged water heaters and steam-generation equipment for plumbing, heating and industrial systems. Based in Cheswick, Pennsylvania, the company makes and assembles its products in the United States, with newer offerings aimed at decarbonized systems and data-center cooling applications.CHESWICK, PA
Leonard Powers, IncBorn from New York City’s wartime building boom, Leonard Powers has served the city’s steam systems since 1933. The Manhattan company is known for its deep Con Edison district-steam experience and for maintaining a 24/7 emergency response for building owners across the region. Its newer LPI Energy group extends that long local history into turnkey energy-conservation work for commercial, multifamily, and institutional clients.NEW YORK, NY
EchogenEchogen develops and builds thermal energy systems based on supercritical carbon dioxide, turning waste heat into power and storing electricity as heat for grid and industrial applications. The Akron company brings nearly two decades of sCO₂ development to hands-on engineering, with systems designed, tested, and refined by its own team rather than left at the concept stage. Its 1.5 MWth heat engine completed more than 100 hours of autonomous operation at 600°C in 2024, while its power-conversion technology is also being developed for advanced nuclear reactors.AKRON, OH