Comparing Measured PV Module Power to Nameplate Values

Within the frame of a market study, the nameplate values of 40 PV modules of 22 different module types from market-relevant manufacturers are compared. The PV modules are measured with an LED-based solar simulator of class A+A+A+ and an uncertainty for Pmpp of 0.9 % (k=2). To cross-check our results, 2 PV modules of different types are also measured using the direct sunlight method with our solar module tube. In both approaches, the respective I-V characteristic is recorded and corrected to standard test conditions in accordance with IEC 60891. The LED simulator has been used to determine the relative spectral responsivity of the modules and a spectral mismatch correction has been conducted in accordance with IEC 60904-7 for both, indoor and outdoor measurements. The determined Pmpp from our solar simulator shows an average deviation from the nameplate value of around -1.33 %. A cross-check with our solar module tube is in accordance with results of the solar simulator. For all measured PV modules, the power values are specified higher on the nameplate than the real power values measured by our facilities.