Comparison of Hot Spot Investigations of Photovoltaic Modules at Laboratory and Field Conditions

Summary: In PV applications solar modules are not always fully illuminated but occasionally partly shaded. In this case the partly shaded cells potentially operate in reverse bias of the current voltage characteristic. For this reason the cells heat up and in the worst case the polymer foils can melt. For studying the thermal stability of a module the standardized hot spot test can be applied. The standardized conditions of the hot spot test allow some degrees of freedom like the module temperature of the non shadowed module area. In this work, the influence of the module temperature and of the radiation level on the maximum hot spot temperature will be analyzed indoor. Then, an outdoor hot spot tests will performed. Finally, this paper will show a worst case comparison between the inand outdoor hot spot test conditions. For more Information on the topic please contact the R&D Team of PI Berlin. Paper available at: www.eupvsec-proceedings.com