Kilowatt-Range Optical System for Driving the Solar Stirling Engine

The Cassegranian-type optical system for driving the solar Stirling engine consisted of a parabolic mirror with a diameter (D) of 3.2m and a hyperbolic mirror with a D of 600mm. The parabolic mirror was of the segmental-type which consisted of 180 ellipsoidal mirrors made from glass plates, and the hyperbolic mirror was made from Al plate. The Stirling engine was developed by Isshiki et al in order to convert solar heat energy into electric power. For driving this Stirling engine, the cylinder head was directly heated by the sun rays converged by this optical system, and the temperature of the cylinder increased up to 700 /spl deg/C. Finally, the engine produced an output power of about 1kW.