Uncertainty in Photovoltaic performance parameters – dependence on location and material

When considering the system yield, one needs to know the uncertainty in key parameters for the annual yield in order to determine the confidence limit. This requires a consideration not only of the instrumentation but also of the operating environment. The importance of this is demonstrated by carrying out an uncertainty analysis for different locations, technologies and instrumentations. The accuracy of the key parameters is determined with regards to whether the uncertainty margins allow meeting contractual obligations for guarantees of results. It is shown that different operating environments have different boundaries. The main uncertainty is in the irradiance which ranges from 0.6-1.5% and filters into the PR with up to 6% for northern Europe (Site 1).