26 Development of a Two-Stage Solar Concentrator Using Fresnel Lens and Dish Reflector

This paper is aimed to develop a two-stage solar concentrator based on Fresnel lenses or dish reflectors for natural lighting and solar energy application in high concentration ratios. Three kinds of solar concentrating devices, namely, Fresnel lens, convex lens, and parabolic dish are considered and integrated in different ways to configure the solar concentrator. It is classified that the concentration system with two-stage reflection can have higher optical efficiency than that with two-stage refraction, but more accurate tracking is required. Detailed analysis and comparison of solar energy collection and transmission processes are made in order to have a practical use of point focusing concentrator devices. A set of highly concentrated solar energy system with two-stage refraction process, namely, two-stage Fresnel lens solar concentrator is built and initially tested.