Optics design key points for high-gain photovoltaic solar energy concentrators

Last advances in optical design and manufacturing have helped to enlarge possibilities for optical solutions in any field that used optics elements. However, the useful solution is not always the best theoretical achievable one. Now, to find the right solution, the restrictions usually do not come from theoretical limits of optics, but from the feasibility of its practical implementations. This paper analyzes a set of important figures to be considered in the design of concentration optical system for photovoltaic solar energy applications. To illustrate it, the ISOFOTON optical concentration option will be presented. It is based in an innovative design methods of non-imaging optics and it is called TIR-R[1]:a two stage concentrator with a primary lens, working mainly by total internal reflection, plus a secondary lens, working by refraction.