Numerical and Experimental Evaluation of Nonimaging Flat Fresnel Lens

The nonimaging Fresnel lens has been developed for advanced solar concentration systems as thermal concentrator or for photovoltaics generation of electricity. Nonimaging flat Fresnel lens was designed based on the Edge ray principle and manufactured. The geometrical concentration ratio of the lens is 19.3. The lens needs to track the sun by one axis. The lens was evaluated by ray tracing method and by experiments under the sun. Result of the simulation and the experiment show that flux density changes according to incidence angles and that the optical concentration ratio is 15.2. The optical efficiency is 79.1% under normal incidence. The lens is capable of concentrating solar ray in a wide range of wavelength.