A comprehensive assessment of electrical performance and mismatch losses in bifacial PV module under different front and rear side shading scenarios

Abstract

Bifacial modules are expected to enable greater energy generation at reduced cost owing to their dual face absorption nature, however this requires an in-depth understanding of the inherent self-shading of module. A cumulative effect of front and rear side inhomogeneity of irradiance may lead to difference in electrical performance of a bifacial module with respect to monofacial module, under similar shading scenarios. In this research work, an extensive analysis has been carried out through ray tracing simulations and a cell level electrical model of a bifacial module to evaluate the effect of front and rear side inhomogeneity in irradiance. The results for front side shading present a likeness to monofacial modules under similar shading conditions. The more critical and inherent rear-side inhomogeneity along with associated mismatch losses have been quantified through a novel linear model, developed to predict the mismatch loss in a bifacial PV module with high accuracy (R2 91.4%, MAE 1.63% and RMSE 1.91%). Using the model, discussion has been presented on mismatch losses in a 3x3 bifacial PV array, demonstrating the impact of rear inhomogeneity induced mismatch losses on overall system performance. A novel sensitivity study is also carried out to assess the impact of installation parameters on mismatch losses. The significance of this study is the importance of such in-depth assessment for future reliability studies as well as developing standard procedures for hotspot testing and mitigation for a bifacial PV module.