Optimizing Bifacial Solar Modules for Enhanced Energy Capture on Cloudy Days

Abstract

To improve the utilization of solar irradiance by a bifacial photovoltaic (PV) flat single-axis tracking system under complex weather conditions, a dynamic optimization model for bifacial PV modules, a hybrid tracking algorithm was developed. Scattering coefficients are defined to differentiate weather conditions consistently so as to select different algorithms for tracking. The sun's position is tracked by using the visual sun trajectory model on sunny days, while the maximum sum of irradiance of bifacial modules is used as the tracking angle setting principle for high scattering weather. A month-long controlled field experiment was conducted at a PV plant in Ningxia. Data under typical cloudy and overcast conditions were selected to analyze and verify whether the proposed model can improve the power generation efficiency of the planar single-axis tracking system. The experiment results show that the tracking system using the all-weather dynamic optimization model for bifacial modules has an irradiance gain of 8.174% and 4.81%, and a daily power generation gain is 10.529% and 6.20%, respectively, under typical cloudy and overcast conditions. This demonstrates that the hybrid tracking model proposed in this article can improve the power generation of the bifacial flat single-axis tracking system under complex weather.