Concentration of fiber transmitted solar energy by CPC for solar thermal utilization

Parabolic dish systems equipped with optical fiber transmission of highly concentrated solar energy can provide a stationary high temperature or high photon density point to us. This is very useful for the applications of solar thermal utilization system, for example solar chemistry on terrestrial or heat source in space. However, the solar energy density sharply decreases form at the end point of the optical fiber, because the transmitted solar light disperses from the exit of the optical fiber according to its numerical aperture. To overcome this problem, we are investigating the CPC (Compound Parabolic Concentrator) coupled to the exit of an optical fiber. This method is capable of increasing the solar energy density emitted from optical fibers. In this paper, we report the experimental results from transmission of solar energy concentrated by a parabolic concentrator through an optical fiber bundle coupled with CPC. Comparing the spatial energy distribution at the CPC exit with that at the entrance of CPC, it is demonstrated that the density of thermal flux is increased about 3.6 times by CPC.