Performance prediction of Building Integrated Photovoltaics under no-shading, shading and masking conditions using a multi-physics model

Under shading/masking conditions, electrical performance of Building Integrated Photovoltaic systems is always the emphasis of previous researches. But thermal and structural performance, which are essential for electrical prediction accuracy and lifespan of the system, are overlooked. This paper is the first to present a verified multi-physics model to predict the electrical, thermal and structural performance under no-shading, shading and masking conditions, as well as when the hot-spot occurs. Particularly, the model contains a simplified electrical mathematical model that is capable of simulating the power output of PV systems under shading conditions and under masking conditions in one expression. Furthermore, the thermal model results have been compared with temperature distributions of the PV module in a full scale with maximum 0.8 °C root mean square error. Using the developed model, it is shown that differentiating shading condition and masking condition is necessary for yield prediction in practical projects. Shading/masking conditions result in the increase of PV cell stress, which degrades the electrical performance. The maximum displacement of the PV cell suffering hot-spot, up to 0.85 mm, is further beyond the compression range of ethylene vinyl acetate, causing structural damage to the PV module even not on fire.