Comparison of module temperature measurement methods

Aim of this study is to improve the prediction of electrical energy yield especially for PV modules based on thin film technologies. Problems with deficient power prediction of PV power plants have manifold reasons: One of the easy accessible is the measurement of NOCT (nominal operation cell temperature). Deviations of NOCTs measured have a direct influence of the yield predicted (1-5%). The deviations due to different measurement methods and different temperature sensors have been discussed in theory (systematic error) and have been investigated in laboratory tests as well as under real world conditions in an outdoor lab. The thermal behavior is studied and the measurement results are compared to theoretical models. As a result the theoretical yield as a function of the measured NOCT is compared for different installation sites and for different technologies.