Flux densities in optimum nonimaging Fresnel lens solar concentrators for space

This paper aims at the clarification of flux density issues in solar Fresnel lens concentrators for use in space photovoltaics. Using the novel nonimaging Fresnel lens designed and prototyped by the authors as an example, flux densities are described as dependent on optical concentration ratio of the lens, solar disk size and related brightness distribution, and spectral dispersion of incident sunlight. Discussing the results of a simulation, the optimum linear nonimaging Fresnel lens concentrator is proposed in terms of concentration ratio, i.e. acceptance half angle pairs