Stirling Engine

A heat engine of the reciprocating (piston) where the working gas and a heat source are independent. The working gas is compressed in one region of the engine and transferred to another region where it is expanded. The expanded gas is then returned to the first region for recompression. The working gas thus moves back and forth in a closed cycle.

Named after its inventor, a reciprocating engine that converts heat into useable mechanical energy (shaftwork) by the heating (expanding) and cooling (contracting) of a captive gas (a working fluid) such as helium or hydrogen. As a solar energy technology, the Stirling engine uses sunlight reflected off a parabolic surface to heat hydrogen to drive the engine that in turn drives a mechanically connected generator to produce electricity.