A simple approach to estimate the Performance Ratio of distributed PV plants

The Performance Ratio (PR) is the most frequently used figure to characterize the quality of design and components of a photovoltaic power plant (PVP). It is usually calculated from the measured irradiation in the generator plane and the generated photovoltaic energy (final yield). Unfortunately, at the most PVPs no irradiation sensor is available.
The paper presents a simple approach to estimate the performance ratio from daily energy measurements and terrestrial irradiation measurements in the neighbourhood of the PVP. The approach is verified in Saxony, based on irradiance ground data collected by the Saxon agro-meteorological measuring network.