Design of Novel Compound Fresnel Lens for High-Performance Photovoltaic Concentrator

Lei Jing,Jialin Xu,He Wang,Hua Liu,Zhenwu Lu,Hongsheng Wu,Huifu Zhao

doi:10.1155/2012/630692

Lei Jing, Jialin Xu + Show 5 more

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https://doi.org/10.1155/2012/630692

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Abstract

We present a new design of compound Fresnel-R concentrator which is composed of two lenses: a primary lens (Fresnel lens) that works by total internal reflection at outer sawteeth but refraction at inner sawteeth, and a ringed secondary lens that works by refraction. In contrast to previous Fresnel lens concentrators, this design increases the acceptance angle, improves the irradiance uniformity on the solar cell, and reduces the aspect ratio significantly. Meanwhile several sawteeth of the primary Fresnel lens can correspond to a same ring of secondary lens, which will efficiently lower the complexity of designing and manufacturing. Moreover, in order to reduce the influence of manufacturing tolerances and to increase the optical efficiency further, the central part of the bottom of the secondary lens which directly adhered to the solar cell is designed as a cone-shaped prism to collect the sunlight that does not reach the solar cell. Finally, we provide simulations and analyses of the design method an optical efficiency more than 80% and an aspect ratio smaller than 0.5 can be achieved.

Highlights

The photovoltaic industry is growing rapidly today; it is still limited by the high cost of photovoltaic systems, especially the expensive semiconductor material
We present a new design of compound Fresnel-R concentrator which is composed of two lenses: a primary lens (Fresnel lens) that works by total internal reflection at outer sawteeth but refraction at inner sawteeth, and a ringed secondary lens that works by refraction
Several sawteeth of the primary Fresnel lens can correspond to a same ring of secondary lens, which will efficiently lower the complexity of designing and manufacturing

Summary

Introduction

The photovoltaic industry is growing rapidly today; it is still limited by the high cost of photovoltaic systems, especially the expensive semiconductor material. The first photovoltaic integrating concentrator was proposed by Sandia National Labs in the late 1980s [4], which used a Fresnel lens as the primary lens and an imaging single surface lens as the secondary lens to obtain the uniform irradiance distribution on the cell, and it was commercialized later by Alpha Solarco. This kind of concentrator consists of two imaging optical lenses, where the Fresnel lens is placed at the single surface lens’ focal plane, and vice versa. A cone-shaped prism to collect the sunlight that does not reach the solar cell is added to consummate the CPVs, which will increase the optical efficiency further

Design Method

Example and Discussions

Findings

Conclusions