INTERCOMPARISON OF DIFFERENT ENERGY PREDICTION METHODS WITHIN THE EUROPEAN PROJECT 'PERFORMANCE' - RESULTS OF THE 2ND ROUND ROBIN

摘要

This paper presents some of the results obtained within the European project PERFORMANCE in the field of module energy prediction. It describes the second of three modelling inter-comparison campaigns (round robins). The main aim of the study is to further reduce and to better understand the uncertainty in energy predictions and to support the development of the IEC61853 energy rating standard for PV modules. The round robin results showed that an improvement in energy predictions by implementing spectral and angle of incidence effects is very difficult to achieve without increasing the reliability and availability of the required input parameters. Independently of the type of technology, none of the seven models investigated was able to significantly improve the annual energy prediction respect to the basic approach where only in-plane irradiance, as measured by a broad band pyranometer, and measured back of module temperature were used as input. A real improvement could only be achieved for clear sky days. The temperature models were shown to be less critical, leading to no major decrease in annual energy prediction accuracy. However, the translation from horizontal to in-plane irradiance led to larger errors, these were mainly due to the high uncertainty in diffuse irradiance measurements and/or its translation to the tilted plane.