Electrical Modeling of Bifacial PV Modules

Although the bifacial photovoltaic (PV) module is now a mature technology, there still exists a gap in the literature on its electrical modeling and equivalent circuit representation. Most published studies have mainly focused on the photocurrent while overlooking other crucial parameters for the electrical response of the module. Even so, the photocurrent of the bifacial module is simplistically treated as the sum of individual currents of the front and rear sides, a hypothesis challenged in this study. Notably, our research has uncovered a discrepancy that can exceed 15%, and we address this issue by introducing a correction factor in this article. This article introduces a comprehensive electrical model that effectively integrates bifacial PV modules' front and rear sides into a single $-$ circuit representation. This novel model adopts the single $-$ diode equivalent circuit, formulating each of the five parameters as a function of the individual side's parameters. Indoor and outdoor measurements validate the accuracy improvement brought by this model, which can benefit energy yield studies and our theoretical understanding of bifacial PV systems.