Assessment of the electrical and thermal performances of building integrated bifacial photovoltaic modules

In recent years the installation of photovoltaic modules integrated into the building envelope, namely Building Integrated Photovoltaic (BIPV) systems, are having an increasing diffusion. As they allow to locally produce renewable energy as well as replacing conventional construction elements providing savings in materials and construction times. Bifacial photovoltaic (bPV) modules could represent an interesting alternative to mono-facial PV modules even in the framework of building integration if the bi-faciality power production is harvested. In this study, a novel mathematical model, which allows evaluating the electrical and thermal energy balance of BIPV façades, is presented. The analysis is carried out through simulations in transitory conditions considering four alternatives configurations of building integrated active facades. In particular, non-ventilated (BIPV) and ventilated façade (V-BIPV) realized with mono facial panels, ventilated active façade realized with bifacial panel (V-BIbPV). This last configuration is also investigated adding a reflective surface on the rear side of the bPV panel (Vr-BIbPV). The results of the simulations, carried out assuming the weather data in Catania (Italy), indicate the glass-glass bifacial photovoltaic façade gives rise to an energy yield of about 5% more than the mono facial BIPV façade.