 Waltham, Massachusetts--Newsfile Corp. - July 20, 2021 - Tecogen Inc. OTCQX: TGEN, a clean energy company providing ultra-efficient and clean on-site power, heating, and cooling equipment, is pleased to announce the completion of 25 long-term maintenance services contracts with the management of a large residential complex in Toronto, Ontario. The 20-year contracts provide for the maintenance of 31 InVerde e cogeneration systems as well as ancillary components. The systems will be serviced out... 