Tecogen, Inc. engages in the design, manufacture, marketing, and maintenance of cogeneration and combined heat and power products. It operates through the Products and Services; and Energy Production segments. Read More The Products and Services segment designs, manufactures, and retails industrial and commercial cogeneration systems. The Energy Production segment sells energy in the form of electricity, heat, hot water, and cooling to customers under long-term sales agreements. The company was founded by George N. Hatsopoulos and John N. Hatsopoulos in 1987 and is headquartered in Waltham, MA.