Design analysis of a Fresnel lens concentrating PV cell

Abstract

Concentrating photovoltaic (PV) systems provide an effective way to reduce the cost of electricity production by reducing the amount of silicon required. The use of a Fresnel lens is one of the typical design options for the concentrating PV systems. Compared with a parabolic mirror, a Fresnel lens has its focus behind the lens surface. This gives a convenience for installation of PV cells and also there is no matter of shading caused by the PV cells. However, both Fresnel lens and parabolic dish concentrating PV systems need to be accompanied by a high accuracy sun-tracking system. This study presents the design analysis of a Fresnel lens concentrating PV cell which consists of a small linear Fresnel lens and a strip PV cell. A number of cells may form a modular large concentrating PV system using a single sun-tracking system. Based on the analysis of the ray path through the Fresnel lens and a current density distribution model for the PV cell, a computer program has been produced to predict the irradiance distribution on the PV cell and the distribution of current density. The results are used to determine the effect of sun-tracking deviation and PV cell position on the PV current distribution. The calculated and experimental short-circuit current and open-circuit voltage of the designed Fresnel lens concentrating PV cell are also given. © The Author 2011. Published by Oxford University Press. All rights reserved.