This paper firstly introduces the principles of Refrigerant Phase-Change Stirling-Cycle solar power towers This heat engines use solar reservoire. When the refrigerant in an engine cylinder absorbs heat from high-temperature heat sources, refrigerant is transformed from liquid to gas and the volume of the refrigerant expands to drive the piston apply work. When the refrigerant releases heat to low-temperature sources, the volume of the refrigerant shrinks. So the refrigerant is transformed from the gas back into liquid. It can use solar energy and industrial waste heat as high-temperature heat sources and there is no gas emission. An industrial-waste heat-driven Stirling engine is modelled as a combined system which consists of a heat exchanger and a Stirling engine. The performance of the system is investigated, based on the linearized heat loss model of the heat exchanger and the irreverisible cycle model of the Stirling engine affected by finite-rate heat transfer and regenerative losses. The maximum efficiency of the system and the optimal operating temperature of the heat exchanger are determined.