Founded in 2017, Aestus Energy Storage is developing infrastructure-grade thermal energy storage systems that convert electricity to heat and back again for grid and commercial use. Based in Pittsford, New York, the founder-led company uses a closed-loop Brayton cycle and a proprietary ceramic storage core rather than a chemical battery, targeting 50-plus years of operation with no performance degradation. Aestus is currently moving from research and development into a subscale pilot project, with its first full-scale commercial installation targeted for late 2026.
MicroEra PowerRochester-based MicroEra Power develops THERMAplus™, an on-site thermal energy storage system that helps commercial buildings shift heating and cooling loads to lower-cost, lower-carbon periods. Its tunable phase-change materials and smart controls integrate with existing HVAC equipment, while expanded laboratory space supports building and testing the system at scale. Founded by CEO Eleanor Rusling and CTO James Grieve, the company’s work is supported by NYSERDA and the U.S. Department of Energy.ROCHESTER, NY
Key Capture EnergyFounded in 2016, Albany-based Key Capture Energy develops, constructs, owns and operates utility-scale battery energy storage systems that help balance the U.S. electric grid. The independent power producer uses in-house market optimization software to manage its batteries, with more than 620 MW operating and a development pipeline exceeding 10,000 MW across the country. Its projects span from New York to Texas and are designed to make renewable power available when the sun is not shining or the wind is not blowing.ALBANY, NY
SunampFounded in 2005, Sunamp is a Scottish thermal-storage company whose factory, research laboratories, and customer training centre sit near Edinburgh. It makes compact heat batteries for homes, commercial buildings, and industrial users, with a focus on making renewable energy practical where conventional hot-water storage would take up too much space.TOWER 49, 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