Modelling and experimental study of PV cells in lens-walled CPC PV system

The concentration photovoltaics (CPV) application promises to produce lower price electricity with less semiconductor usage in comparison with the common flat plate PV module. The compound parabolic concentrator (CPC) shows great potential in both economics and efficiency in low the concentration photovoltaics (LCPV) system because it does not require a tracking system and is able to concentrate light with a large incident angle range. A detailed investigation has previously been carried out regarding the novel CPC module purposed (Su et al., 2012a). The validation of the experiment shows the Lens-Walled CPC gives a superior optical and electrical performance compared with other CPCs. Non-uniform light distribution is a common issue with all CPC designs as it has a major influence on the concentration of solar cell performance. In order to study the effects of non-uniform distributed light on solar cell behavior in-depth, two simulation approaching methods including array modelling and finite element modelling (FEM) were carried out. Both simulation approaches observed a reduction in the solar cell fill factor (FF) under non-uniform distributed light. The high resistive losses in the cell are the main cause of this phenomenon. Three simulation models with different cell grid designs were studied to further study the influence of non-uniform distributed light. The light profiles from three different CPCs were implemented with the FEM model. The result shows although solid CPC has the highest current output in a certain condition, the Lens-Walled CPC has the most uniform light distribution, which reduces the influence from non-uniform light distribution to solar cell performance. Key words: PV; CPV; Lens-Walled CPC; Array modelling; Non-uniform light distribution; FE