Microturbines

Stirling engines are cost competitive with other small generator technologies, up to about 100 kW. The Stirling engine is externally heated, usually by combustion, to warm a gas that drives either pistons connected to a rotating power shaft or oscillating pistons that are supported by mechanical springs and gas bearings. Targeting the residential cogeneration market, many are packaging Stirlings as electric furnace or boiler replacements. Stirling cogeneration is popular in Europe.