Abstract: A closed cycle, hydraulic-turbine heat engine for providing a steady electrical or mechanical power source from any available or created relative heat source comprising an evaporation chamber, a vapor conduit connected to the evaporation reservoir and extending vertically therefrom, a condensing reservoir at the upper end of the gas conduit, and a liquid conduit between the condensing reservoir and the evaporation chamber. The liquid conduit, vapor conduit, evaporation chamber, and condensing reservoir form a closed system for containing a refrigerant. A heat exchanger coupled to an external heat source is arranged to provide heat to the refrigerant in the evaporation reservoir, and a condenser, coupled to a heat sink, condenses refrigerant vapor entering the condensing reservoir from the vapor conduit.