Solar-radiation concentration in the Fresnel lens: an optical medium system
Abstract
One of the tasks of Fresnel lenses (FLs), which are used in solar micromodules jointly with cascade photocells, is to increase the concentration capability. This paper considers the solution of this task at the expense of using optical media (L). A program for the numerical simulation of the concentration characteristics of the FL-L system has been developed with allowance for inaccuracies in FLs and Fresnel losses at the interface of media. It is shown that the average concentration can be increased by 36% in the FL-L system for the case in which there is 95% receiver capture of a flow going from a medium and, as a whole, with allowance for losses at the medium-photocell boundary (they can be regulated), the growth in an average concentration for a silicon solar cell without coating will be 20–25%. At a smaller acceptable percentage of flow capture (if there is a goal to increase concentration), the efficiency of optical media in the FL-L system grows and can reach the values obtained in the paraboloid-optical medium system.