Performance Ratio
The Performance Ratio (PR) is a measure of the efficiency with which a PV plant is operating. The calculated yield of the plant is compared to the annual POA normalized by the reference irradiance, \(G_{\text{ref}}\), 1000[W/m²].
$$Yield = \frac{\Delta t\left\lbrack h \right\rbrack\sum_{}^{}E_{grid,act}\lbrack W\rbrack}{total\ DC\ capacity\lbrack Wp\rbrack}$$
$$Capacity\ Factor = \frac{Yield\lbrack kWh/kWp\rbrack}{8760\lbrack h\rbrack}$$
$$PR = \frac{\text{Capacity\ Factor}}{\frac{\Delta t\sum_{}^{}G_{\text{poa}}\lbrack W/m^{2}\rbrack}{\left( 1000\lbrack W/m^{2}\rbrack*8760\lbrack h\rbrack \right)}} = \frac{Yield\lbrack kWh/kWp\rbrack}{\frac{\Delta t\sum_{}^{}{G_{\text{poa}}\lbrack W/m^{2}\rbrack}}{\left( 1000\lbrack W/m^{2}\rbrack \right)}}$$