In this study, we investigate the Performance Ratio (PR) of about 100 German PV system installations. Annual PRSi for the ~100 systems are found to be ~70%...~90% for year 2010, with a median of ~84%. Monitored PR are found to be systematically lower by ~2%…4% when calculated with irradiation data obtained by pyranometers (henceforth PRPyr) as compared with irradiation amounts measured by reference cells (denoted PRSi). Simulations were performed to determine loss mechanisms of the top ten performing systems, revealing a number of these loss mechanisms may still allow for some optimization. Despite the fact that we do not see such values from our monitoring data base up to now, we believe PRSi values above 90% are realistic even today, using todays commercially available components, and should be expected more frequently in the future for systems in which temperature and irradiation conditions are similar to those prevailing in Germany. This contribution may help in deepening our knowledge on both energy loss mechanisms and efficiency limits on the system level and standardization processes of system aspects.

26th European Photovoltaic Solar Energy Conference and Exhibition; 3922-3929