Design of Curved Fresnel Lens with High Performance Creating Competitive Price Concentrator Photovoltaic

In this paper, the design of a curved Fresnel lens applying to the concentrator photovoltaic system is proposed by using the edge ray theorem, the Snell’s law, and the conservation of optical path length. The new structure of the curved Fresnel lens can improve significantly the uniformity of sunlight distribution over the solar cell while the concentration ratio can reach a high value of 900 times. The good uniform distribution can be obtained by using the novel idea. The novel idea is based on the uniform sunlight distribution of every groove of the lens so that the whole lens also distributes uniformly the sunlight beam over the receiver. The structure of the lens is built by two surfaces: input surface (or upper surface) as a part of spherical surface and output surface (or lower surface) that consists all grooves of the lens. Matlab program is used to design the input and the output surfaces of the lens. The input surface and the output surface are independent to each other in construction in Matlab. LighttoolsTM software is used to optimize the structure of the novel lens. Furthermore, LighttoolsTM is also used to perform a simulation to examine the efficiency of the lens in concentrator photovoltaic (CPV) system by using the light source with a wide spectrum of 380 – 1600 nm. The results show that the lens has an acceptance angle of 0.80 and good optical efficiency (>85%).