Design of a 2.5kW Low Temperature Stirling Engine for Distributed Solar Thermal Generation

This paper focuses on the design of a Stirling engine for distributed solar thermal applications. In particular, we design for the low temperature differential that is attainable with distributed solar collectors and the low cost that is required to be competitive in this space. We will describe how these considerations drive the core design, the methodology for improving the design, and summarize progress made in fabrication of the engine for experimentation. Stirling engines can have broad significance and technological advantages for distributed renewable energy applications. A key advantage of a solar thermal system is that they can incorporate thermal energy storage in a cost-effective manner. In addition, Stirling engine systems are fuel-flexible with respect to the source of thermal energy and unprocessed waste heat can be harvested for CHP purposes as well. The ability to extract unconverted thermal energy for waste heat applications greatly improves the overall thermal efficiency of the system.