Performance analysis of crystalline silicon and amorphous silicon photovoltaic systems in Iowa: 2011 to 2014

Iowa City is in the humid continental climate zone and the goal of this paper is to provide a thorough system performance analysis for PV systems installed in this climate zone. In this work we present the performance analysis of two photovoltaic (PV) systems installed at The University of Iowa in mid-2011. We analyze the system performance from mid-2011 to 2014. First system is a 39 kW-DC building-integrated amorphous silicon (a-Si) PV array. Second system is a 48.1 kW-DC solar charging station based on multicrystalline modules. We use National Renewable Energy Laboratory's System Advisor Model for the PV system performance analysis of the two systems and results of simulation are compared to measured energy yield. In addition, we compare PV system performance with the Iowa Energy Center Solar Calculator (IEC-SC) model for the mc-Si PV system. Our analysis indicates that the SAM model, with correct modeling parameters results in ±20% error relative to measured data whereas the IEC-SC model almost always over estimates the energy yield.