• operational performance analysis;
  • trends in long-term performance;
  • reliability of grid-connected PV systems;
  • low-yield analysis;
  • system availability;
  • PV performance database


This paper presents operational performance results of grid-connected PV systems in Germany, as collected and elaborated for the Photovoltaic Power Systems Programme (PVPS) of the International Energy Agency (IEA). Performance ratios obtained from 235 PV installations in Germany and from 133 PV plants in other countries are compared and discussed. For Germany, a significant rise in PV system performance and reliability was observed for new PV installations due to higher component efficiencies (e.g., inverter) and increased availabilities.

There is a lack of long-term experience in performance and reliability of PV systems, owing to the absence of monitoring programmes. As an outcome of IEA PVPS collaborative work, Task 2 provides reliable and worldwide monitoring performance data and results ( Technical and operational data is available for system planning and comparison, for teaching and training purposes as well as for future developments of financing schemes (e.g., feed-in-tariffs) in order to stimulate the PV market. Copyright © 2004 John Wiley & Sons, Ltd.