Abstract: A waste heat recovery system incorporates a contactor for counter current direct heat exchange between a non-condensible gas and a liquid, typically hot water. The water is from a heat source available at the site such as a solar source, a geothermal source, an industrial plant or the like. Hot mainly saturated gas exits from the contactor and drives a motor, typically a turbine. The turbine drive a work consuming device, normally an electric generator. A condenser/separator downstream from the turbine condenses the water vapor and separates the non-condensible gas from the liquid. The liquid from the condenser is preferably recycled or may be discarded.