High-performance Kohler concentrators with uniform irradiance on solar cell

Abstract

A new free-form XR Kohler concentrator is presented that combines high geometric concentration, high acceptance angle and high irradiance uniformity on the solar cell. This is achieved by modifying the optical surfaces to produce Kohler integration. Although the new optical surfaces (that is, the ones including Kohler integration) behave optically quite different from the ones that do not integrate, but from the macroscopic point of view they are very similar to them. This means that they can be manufactured with the same techniques (typically plastic injection molding or glass molding) and that their production cost is the same i.e., with a high potential for low cost and high optical efficiency. The present approach is completely new and allows keeping the acceptance angle at high values and the concentration factor without increasing the number of optical elements. The simulated optical performance of a Kohler integrating solar concentrator is presented. This concept is the first design combining non flat array of Kohler integrators with concentration optics.