Seasonal Dependence of Bifacial Photovoltaic Array Gain due to Inverter Clipping

This paper studies the effect of inverter clipping in bi-facial photovoltaic (PV) array under different ground cover reflectivity. The 5 kW bi-facial array was installed at the University of Delaware, USA and was connected to 3.8 kW grid tied inverter. Two parameters, expected PV power and DC energy efficiency, were developed in this research to compare the inverter clipping loss with actual data collected from on-site sensors. The results show that the clipping potentially occurs in summer from 10:30 to 14:30 due to high solar irradiance. The daily generation with the white ground cover experienced higher clipping loss than the gravel and consequently resulted in negligible bi-facial gain. In winter, the bi-facial gain is higher as the clipping loss is absent.