An optimum design and properties of a static concentrator with a nonimaging lens

An optimum design of a lens-type static concentrator was carried out using a ray-tracing program. The optimum concentrator was determined by calculation of annual integrated power for several different concentrators and also flat-plate ones. Using average sunlight data for ten years, a maximum average output ratio of the concentrator to the flat-plate modules at the same cell area condition was 1.7 at a half-acceptance angle of 25/spl deg/. Also, the best half-acceptance angle, was calculated to be 25/spl deg/ by taking account of the shadowing effect. In experiments under a solar simulator, if was shown that the best half-acceptance angle was obtained at 25/spl deg/. This suggests that an occupied area of costly crystalline Si cells in the static concentrator can be reduced to 60%.