The operating temperature of a PV module or system is a crucial parameter for its energy output. PV modules are in fact usually rated at Standard Test Conditions (STC = 1000 W/m2, AM1.5, 25°C), but their operating temperatures are usually significantly higher. In order to have an idea of their temperature behavior- an information which may result useful in optimizing the output of a PV system under particular conditions - in the present work we have compared indoor measured temperature coefficients values of several thin film technologies (a-Si based single or multi-junctions, CdTe, CIS, thin-film silicon) with typical TCO’s of a conventional c-Si wafer-based module. With the exception of the thin film Si device (rel = -0.48 %/°C), all thin film technologies have lower values for the rel temperature coefficient for power compared to the c-Si wafer-based module (rel = -0.45 %/°C), with the a-Si single-junction (rel= -0.13 %/°C) device showing the less pronounced decrease with temperature, followed by CdTe (rel= -0.21 %/°C). The microcrystalline and CIGS device investigated in this work have TCO values for power very close (rel= -0.36 %/°C). At least for the single-junction devices, the magnitude of the power temperature coefficient seems to be strongly correlated to the band gaps of the corresponding absorber materials. TCO values presented in this work are in line with data coming from the literature and or from manufacturer’s datasheets. It should, however, be noted that for a given technology a significant spread for TCO values may exist.

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 4248-4252