A comparative of four secondary optical elements for CPV systems

Abstract

The study concerns the use of four secondary optical elements (SOE) in a photovoltaic solar concentrator using the same primary optic element: the Fresnel lens. In this work, a detailed optical modeling is applied to analyze the performance of four refractive secondary optical elements: the Compound Parabolic Concentrator (CPC), the Crossed Compound Parabolic Concentrator (Crossed CPC), the Cone and the Pyramid. Two of the most used materials for manufacturing secondaries are employed, to get a clear idea about the four elements efficiencies and geometrical needs. Efficiencies are compared in term of achieved concentrations, acceptance angle, and the output light power distribution. The geometrical considerations reveal that the length and the input aperture size of the four SOEs increase if the refractive index of the considered material increases. Results show that the pyramid gives the more uniform irradiance distribution and the high optical efficiency whatever the used material, and a largest tolerance angle compared to other authors