CHP systems use both on-site generators to produce electricity and heat recovery technologies to collect and utilize waste heat from the generator. Common on-site generators for CHP systems include reciprocating engines, gas turbines, steam turbines, stirling engines, and fuel cells. Common heat uses are recovery to drive a steam turbine generator, use in industrial processes, use to offset boiler needs, and use to cool spaces through absorption chilling and desiccant dehumidification.