Analysis of a commercial-scale photovoltaics system performance and economic feasibility

Abstract

The performance of a commercial-scale (86.4 kWp) rooftop grid-connected photovoltaic (PV) system was investigated from the measured daily power generation and weather. The PV system was installed in Atlanta, GA, USA, where global solar irradiation varies from 3.3 to 9.0 kWh/m2 day (average: 4.7 kWh/m2 day). Annual power generation measured from this PV system was 110 MWh with a capacity factor of 14.5%. This is also equivalent to a carbon reduction of 25.2 tons/yr. Furthermore, for an accurate assessment of the total system derate losses and the levelized cost of electricity (LCOE), System Advisory Model modelings were performed. From the modelling, the total PV system derate losses were calculated to be 27% (including inverter loss) and the LCOE value was 14¢/kWh. Note that the installed system cost was 4.18$/W when it was installed in 2011, assuming 30 years of lifetime and a weighted average cost of capital of 5.6%. However, in 2016, one can install PV systems only at 2.2$/W instead of 4.18$/W, so the LCOE can be down to 7¢/kWh. As the price of commercial electricity in GA is about 9.6¢/kWh, a LCOE of 7¢/kWh can match the grid parity.