Insolation dependent solar module performance evaluation from PV monitoring data

The quality and performance of the components of a photovoltaic (PV) power plant has an effect on its energy yield. Therefore, it is sensible to select the best performing components in order to get maximized energy yield. But for example the performance of PV modules is often only known at standard test conditions (STC) which are most of the time artificially created in laboratories. Measurement data of over 24,000 PV plants deployed at sites located in Central Europe has been captured for 2009 and 2010. This data was checked by routines in order to provide sufficient data quality. Then it was transformed to STC in order to compare the empiric results of components' performance. This transformation was done using temperature data and plant configuration data e.g. inverter efficiency. With this approach a quasi performance ratio can calculated which allows fair comparism of PV modules and module types under real-life conditions.