Modelling of Pv Modules - the Effects of Non-uniform Irradiance on Performance Measurements with Solar Simulators

The performance data of a PV module are derived from the current-voltage characteristic measured under standard test conditions (STC). For this purpose, test laboratories as well as module production plants employ solar simulators which, depending on type and module size, display a more or less pronounced non-uniform distribution of irradiance in the test plane. In view of the quality assurance for solar simulator test facilities and of the measuring and manufacturing tolerances, it is important to know the effects of non-uniformity of irradiance on the module current-voltage characteristic, and to take the effects into account in the calibration of light sources. This study presents the fundamental effects of a non-uniform irradiance distribution on the module performance. By means of computer modelling the specific influences of the solar simulator system and of solar cell parameters are demonstrated and measurements methods for performance rating of PV modules developed.