We use a "generic cSi model" which is based on data from indoor measurements for 18 different recent mono and poly crystalline PV modules coming from different manufacturers. Details of the model are published in Solar Energy Materials and Solar Cells. The paper is available here.
Results of the study show that the model output of the 18 modules varies with a standard deviation(SD) of 1.22%. The variability between modules of different types is thus smaller than the uncertainty normally found in the total solar irradiation per year for a given site. We conclude that the model can therefore be used for generalized estimates of PV performance with only a relatively small impact on the overall uncertainty of such estimates resulting from different module types