Experimental validation and application of an improved performance evaluation model for bifacial photovoltaic system

With the rapid growth of bifacial photovoltaic (BPV) industry, system performance assessment becomes important. This study proposed an improved performance evaluation (IPE) model for BPV systems, which coupled light, heat, electricity and external environment, and was experimentally validated under different environmental conditions and minimum ground distances (hmgd). Firstly, Monte Carlo ray tracing method was used to simulate the light propagation in BPV system to obtain non-uniform irradiance distributions on front and rear sides of BPV panel. Then the thermal-electrical performance was calculated using finite volume method and discrete integral method, respectively. Finally, experimental validation was conducted. The results show that the maximum relative errors of irradiance on front and rear sides of BPV panel are below 13 %, while the maximum relative errors in temperature and instantaneous electric power (P) are under 12 % on both partly cloudy, windless day and sunny-dominated with few clouds, windy day. As an application, IPE model is used to evaluate BPV system performance under different hmgd, and the maximum relative error is also below 12 %. P reaches the maximum value at hmgd = 560 mm. Overall, IPE model proposed in this study for BPV performance evaluation has good generalizability and credibility under different environmental conditions and installation parameters.