The Stirling Engine - A Ready Candidate for Solar Thermal Power

The paper describes Stirling engine developments at United Stirling of Sweden and the adaptation of their 4-95 double-acting engine as an efficient solar energy converter receiving heat from a parabolic dish concentrator. The engine needs only minor modifications to match requirements of a solar heated powerplant. New heater/receiver designs are described, including the relation of tube geometry to solar flux patterns. The 4-95 engine to be installed for a 1981 DOE demonstration program is predicted to achieve a thermal efficiency of 35 percent at a power output of 22 kW.