US Patent 7617680 Power generation using low-temperature liquids

Methods and systems are disclosed for generating power though the use of thermodynamic engines and low-temperature liquids. A liquid cryogen maintains a temperature differential with a heat source across a thermodynamic engine. The thermodynamic engine is run to convert heat provided in the form of the temperature differential to a nonheat form of energy. Cryogen vapor produced by vaporization of the liquid cryogen is collected and combusted to generate additional energy.