Performance test of a stirling engine generator and its development

Stirling engine is an external combustion engine, offering low noise, reduced emissions (through cleaner combustion), multi-fuel capacity, and long life. Although Stirling engines are appealing for tapping alternate energy sources such as solar power, their energy efficiency and cost should be improved further to be an economically feasible power plant. Based on the author’s experience, several innovative ideas have been incorporated into the design of the advanced Stirling engine and the engine is coupled with a new, light weight, efficient generator/motor. Solar energy is widely used for power generation. One of the technologies, called Dish/Stirling technology uses a mirror concentrator(s), a Stirling engine and an electricity generator. This concept is not new and has been under development for quite some time. However, there are various problems that prevent a solar-Stirling engine generator to be a commercially feasible system. The paper describes the development of an advanced Stirling engine for solar energy system application. The engine has several special features incorporated in the design and provides a cost effective, high performance, and reliable power converter for a concentrated modular solar thermal system. The test results of the engine generator with 1kW output model is shown in the paper. Performance tests are done with the use of propane gas initially and then the engine is integrated with a Fresnel lens solar collector as a total solar thermal system. Heat loss of the engine generator is also investigated.