Tecogen makes natural gas-powered combined heat and power (CHP) systems and gas-engine-driven chillers for commercial and industrial customers. These systems generate electricity or cooling on-site while recovering waste heat from the engine for use in heating or air conditioning, claiming significantly higher efficiency than grid electricity. Tecogen's core products are CHP/cogeneration systems (the InVerde e+ and TecoPower), which generate electricity and hot water for hospitals, hotels, multifamily buildings, and universities, and gas-engine-driven chillers (Tecochill), which produce chilled and hot water for hospitals, ice rinks, food processors, and data centers. Tecogen also offers the Tecofrost refrigeration compressor and the Ultera ultra-low-emissions system. Tecogen operates three segments: Products (~34% of revenue), which sells equipment directly to end users; Services (~61% of revenue), which provides operations and maintenance under long-term, run-hour-based contracts for roughly 764 cogeneration units and 244 chillers; and Energy Production (~5% of revenue), where subsidiary ADGE owns and operates on-site energy systems, selling electricity and heat under long-term energy sales agreements. The services segment is the financial backbone of the business, generating predictable, recurring cash flows. Tecogen sells primarily in high-electricity-rate markets—California, the Northeast, and the Midwest—where on-site gas generation offers the greatest economics. Management has identified AI data centers as the primary growth opportunity, arguing that Tecogen's gas chillers can free up 25–35% of a data center's power allocation for revenue-generating computing. Tecogen signed a sales and marketing agreement with Vertiv in February 2025 to pursue this market globally.