On the performance ratio of photovoltaic installations

The performance ratio is the parameter used worldwide for evaluating the efficiency of photovoltaic (PV) plants and can be used to compare grid-connected PV plants at different locations all over the world. The paper investigates on the effective performance ratio of PV installations in Sardinia-Italy, with a critical analysis of the whole energetic transformation chain, starting from the incident solar energy, to the DC energy output from the modules and AC energy output from the inverter and transformer. All the parameters that can influence the energy production are analyzed in order to find out the critical points in the optimization of the PV installation design process. Two real case studies are presented and discussed in the paper.