Abstract: A co-generation system for producing electricity, heating and cooling and including a combustion unit, a boiler connected to the combustion unit, a steam engine and an electrical generator driven to the steam engine. A condenser is connected to the steam exhaust port of the steam engine, the condenser supplying heat to a heat system and causing condensation of the steam discharged by the exhaust port. An absorption cooler is connected to the exhaust port of the steam engine, the absorption cooler for cooling fluid of a cooling system. A heat pump or centrifugal cooler can also be driven by the output shaft of the steam engine. The co-generation system can also include a flue gas cooler for further transfer of heat to heating system.