Abstract: A system for powering a gas-sealed, flywheel-type turbine comprises a pair of pressurized storage tanks used alternately as a source and sink of Freon. A rotary valve, in a first position, directs liquid Freon from the first storage tank, functioning as a Freon source, to a boiler to produce super-heated Freon vapor. The super-heated vapor is used to directly drive the turbine, and the turbine exhaust vapor is converted back to liquid Freon in a condenser. The high pressure outlet of the turbine is used, via a capillary tube, to supply pressure for forcing the liquid Freon from the storage tank to the boiler. The condensed Freon is then directed, through the rotary valve, to the second storage tank functioning as a Freon sink. When the liquid Freon in the first storage tank is nearly depleted, boiling of the Freon is detected by a thermostatic bulb in thermal contact with the tank bottom.