Modeling of bifacial photovoltaic systems including temperature, albedo and perimeter effects: comparison with data

Bifacial photovoltaics (BPV) is emerging with large momentum as a promising solution to improve the energy yield and reduce the costs of photovoltaic (PV) systems. Bifacial solar cells simultaneously collect incident solar radiation from the sun on the front side and the albedo radiation from the ground on the back side. To reach its full potential, an accurate understanding of the physical characteristics of BPV is required. To this purpose, the model presented in this work has been developed to evaluate the performance of bifacial PV systems ranging from laboratory scale to large farms. The model takes into account the three-dimensional geometry of the whole PV system to accurately evaluate the irradiance impinging on the rear side of each module, which depends on its position within the system. The model has been validated by comparison with experimental data of module temperature, short-circuit current, open-circuit voltage and energy yield of bifacial and monofacial mini-modules. Through this comparison with the outdoor measurements, it has been possible to optimize the ground clearance and tilt angle of a laboratory scale PV system. Moreover, the model has been used to quantify the contribution of the perimeter effect, showing that 2D models tend to underestimate the energy yield as they do not consider that edge modules receive more reflected light on their back side compared to central modules.