Solar-powered Stirling engine
NASA patented a type of solar-powered Stirling engine on August 3, 1976. It used solar energy to pump water from a river, lake, or stream. The purpose of this apparatus is to “provide a low-cost, low-technology pump having particular utility in irrigation systems employed in underdeveloped arid regions of the earth[using] the basic principles of the Stirling heat engine“. Another design was patented by Roelf J. Meijer in 1987. His invention combines a heat engine, such a