Modelling and analysis of the influence of solar spectrum on the efficiency of photovoltaic modules

The article presents the influence of changes in the solar radiation spectrum distribution on the properties of various photovoltaic modules, with particular emphasis on the scattered component. We compared the relative efficiency of the photovoltaic modules based on various semiconductor absorbers during bright and sunny, and cloudy summer days. Additionally, we presented the impact of the module tilt angle on the magnitude of the surface incident scattered component and on the efficiency of the module. The solar spectra for various weather conditions were estimated using specialised computer programmes,such as SolarSpectrum or SMARTS2, and we present here the validation results for the former. The obtained results confirm the published experimental data and the conclusions drawn show the applicability of the tested modules with various absorbers for the specific photovoltaic systems. The theoretical analysis of the a-Si structures, both single-, as well as multi-junction shows better performance of these structures at low-irradiance conditions (in comparison with e.g., c-Si, CIS structures), during days characterised by a spectral distribution common for cloudy days with high air water vapour content. This type of device should show unaltered efficiency both at mid-day, as well as during the morning and late afternoon.