Analysis of annual bifacial gain in energy and annual energy yield of bifacial modules at low latitudes

Bifacial photovoltaic (PV) modules have the advantage of capturing sunlight from both their front and rear surfaces, which can generate more energy than monofacial PV modules. Quantifying the difference in annual energy production between monofacial and bifacial PV modules remains a great challenge. Research and theoretical modeling already exists that explores Bifacial Gain in Energy (BGE) and its dependency on minimum mounting height, tilt angle, and ground albedo. However, few studies have sought to investigate the bifacial PV module annual energy yield model at low latitudes (from 30 degrees S to 30 degrees N). This paper first establishes a relationship between annual BGE and latitude. This claim is then supported by comparing theoretical and experimental values from sites using bifacial PV in Shanghai and Tucson. Second, this research discusses the effect of diffuse irradiance and latitude on annual BGE by analyzing the BGE at 19 different sites all located at low latitudes between 30 degrees S and 30 degrees N. Finally, this research creates an annual BGE model for modules located at low latitudes. The results of this model are in agreement with data collected from research by other researchers. We believe that our model can provide meaningful guidance for designing bifacial module solar power stations.