Optical performance analysis and design optimisation of multisectioned compound parabolic concentrators for photovoltaics application

Currently, all compound parabolic concentrators (CPCs) for photovoltaic (PV) application consist of reflecting surfaces in the form of a parabolic shape. However, parabolic shapes create non-uniform illumination on the PV module, which significantly reduces the power output. To achieve high-concentration ratio and uniform illumination on the PV module, this study proposes the use of flat reflector sections in a symmetric two-dimentional CPC instead of the parabolic shape. This collector is called multisectioned compound parabolic concentrator (M-CPC). However, the main challenge in designing such a concentrating system lies in the determination of the optimal number of flat sections and the width of each section so that the optical properties of the M-CPC approaches that of the standard CPC. In this work, seven M-CPCs having the same designing parameters but with different total number of flat reflector sections were designed. A detailed analysis of the optical performance was undertaken to optimase the M-CPCs. The optimal design was based on-high angular acceptance, low-optical losses, high-optical efficiency in a wide-interval incidence angles, and uniform energy flux distribution on the PV module. Results from the ray trace simulation analysis show that the optimal M-CPC is the design with a total number of seven flat reflector sections (ie, M-CPC7). This design has high-angular acceptance (100%) in a wide-interval incidence angles, low-optical losses (7%), and high-optical efficiency of about 95% in a wide-interval incidence angles. In addition, M-CPC7 illuminates the PV module more uniformly than the standard CPC.