High Performance PV Concentrator

Although new, high efficiency, III-V solar cells have conversion efficiencies approaching 40 percent they are cost prohibitive without increased sunlight concentration. Conventional concentrator designs are capped at 500X magnification. This project will develop a reflective lens optical concept that removes this limit and offers a much greater choice of fabrication techniques and industrial materials for making concentrator modules. The reflective lenses uniquely combine the high concentration ability of parabolic mirrors and the design versatility of Fresnel lenses. The approach also avoids the need for secondary optical stages and aims at achieving manufacturing simplicity, low weight, and improved conversion efficiency. Phase I involved a design study, optical modeling, raytracing experiments, and the fabrication and test of a pilot-prototype concentrator. The resulting optical concentration not only exceeds the minimum benchmark of 500 suns but was close to the ultimate target of 1,000 suns. Phase II will build and evaluate a prototype integrated terrestrial concentrator PV module with high efficiency and a compact form factor. Phase II also will address issues associated with mass production, outdoor stability, and useful lifespan. Commercial Applications and Other Benefits as described by the awardee: The technology should enable the replacement of conventional PV modules with inexpensive, flat-plate III-V concentrator panels that utilize up to 1,000 times less PV materials. Commercialization of the concentrator PV panels will help meet the national goals of securing energy independence and reducing carbon emissions