1. The performance ratio is the ratio of the actual and theoretically possible energy outputs. It is largely independent of the orientation of a PV plant and the incident solar irradiation on the PV plant. For this reason, the performance ratio can be used to compare PV plants supplying the grid at different locations all over the world.
2. The performance ratio is a measure of the quality of a PV plant that is independent of location and it therefore often described as a a quality factor. The performance ratio (PR) is stated as percent and describes the relationship between the actual and theoretical energy outputs of the PV plant. It thus shows the proportion of the energy that is actually available for export to the grid after deduction of energy loss (e.g. due to thermal losses and conduction losses ) and of energy consumption for operation.
Efficiency, Quality, Yield
SMA - Performance ratio: Quality factor for the PV plant (http://files.sma.de/dl/7680/Perfratio-TI-en-11.pdf)
Author: Anas Naddour