Trends In Dish-stirling Solar Receiver Designs

Abstract

The dish-Stirling solar energy system, because of its high efficiency, is a leading candidate for producing low-cost electric power from the sun. Dish-Stirling receiver design involves dealing with non-uniform and highly concentrated solar flux at high temperatures (700 - 800/spl deg/C) and, therefore, presents a variety of technical challenges. The technology is in the process of evolving from directly illuminated heater-head "tube receivers" to receivers that use refluxing (i.e., gravity assisted) liquid metals as an intermediate heat transfer fluid. Modern dish-Stirling development was initiated in the late 1970s by the et Propulsion Laboratory for the Department of Energy. The JPL technology development with United Stirling, Inc. involved the USAB 4-95 Stirling engine and directly illuminated heater-head tube receivers. This work eventually led to the successful demonstrations and world record efficiencies by Advanco Corp. and to the attempted commercialization of the technology by McDonnell Douglas Corp. The severe nature of concentrated solar flux and the potential advantages of heat-pipe technology have caused an evolution toward 'reflux' receivers. These receivers are just beginning to be tested in the laboratory and integratea;@rith dish-Stirling systems. In this paper, the history and current status of dish-Stirling receiver development are presented and discussed. The technical challenges to be addressed by the dish-Stirling community and the future plans at Sandia are outlined.