Modelling the performance of amorphous and crystalline silicon in different typologies of building-integrated photovoltaic (BIPV) conditions

In this work we use and further elaborate a previously proposed model to describe the daily performance ratio of amorphous (a-Si) and crystalline silicon (c-Si) photovoltaic solar modules under real operating conditions. For both technologies, the model was validated against three years of data collected from the outdoor test field at Supsi for a conventional ventilated free-rack mounted installation (south facing, 45(circle)-tilt). In the present work, we expand the simulations to model the performance of the same technologies for the same location and to include building integrated (BIPV) installation conditions. For simplicity, we consider two extreme cases: (a) a south-facing facade installation (90(circle)-tilt) and (b) a perfectly horizontal one (0(circle)-tilt). The angle-of-incidence response of the modules is then used to quantify reflection losses, which are very significant in summer and winter for the facade and horizontal installation, respectively. Further, compared to ventilated ones, fully integrated PV modules exhibit average operating temperatures that can reach an offset of +20(circle)C in days of clear sky conditions. This offset is used to model the operating temperatures - and performance losses - of the BIPV modules. The model, whose main limitation is the focus on days of clear sky conditions, allows assessing the distinguished contributions, and peculiar time-phases, of each effect to the yearly energy performance of the devices under test. (C) 2017 Elsevier Ltd. All rights reserved.