Development of a Small, Free-Piston Stirling Engine, Linear-Alternator System for Solar Thermal Electric Power Applications

The development of free-piston Stirling engines which can meet broad system applications, for example heat-activated heat pumps, electric generator sets, and solar thermal power applications, has been an ongoing effort over the last several years. Free-piston Stirling engines, while having inherently high efficiency, have a number of other attractive features which are considered necessary for solar thermal electric power systems. The elimination of oil from the system, incorporation of clearance seals, operation with gas bearings, and the feature of having only two moving parts offer the potential for long life, high reliability, and maintenance-free operation.

This paper presents a summary of the development of FPSEs for various applications, including designs for small, dispersed solar thermal power, leading to the conceptual design of a small 3-to 5-kW_e electric output solar thermal module.