Fraunhofer ISE says that PV systems in Germany are regularly generating higher yields than expected. The company investigated the issue and published an article saying that the outperformance can be as high as 5%. This seems largely derived from the global warming effect.
Industry players have been experiencing this kind of outperformance in their own operating systems for a long time. Positive deviations between the planned yield and the actual have been up to 20% in some cases. Despite of this fact Banks and Equity investors have never taken the potential outperformance into account when evaluating investments. Hopefully project developers can now count on more realistic cash-flow forecasts for solar PV projects.