Effect of temperature on module performance
All the semiconductor devices are sensitive to temperature change and one can find large change in their characteristics with respect to change in temperature. Main idea behind this article is to explain fundamental of high temperature operation of solar plant that influence energy output, module efficiency and module life. So while selecting module for your solar PV plant, check what the temperature coefficient of the module is?
All the solar PV technology has negative temperature coefficient, so that, as the module temperature rises there will be decrease in generation. Typically a crystalline silicon solar module has temperature coefficient ranging between -0.45 to -0.5% and thin film PV modules have temperature coefficient ranging between -0.25 to -0.35%. So, for a particular technology, one should go with the module having small temperature coefficient. Following graph is clearly showing that Voltage and current behavior with respect to change in temperature.
When one look at the name plate of the solar PV, specification motioned over that plate are on the STC (standard test condition, 1000 W/m2 solar irradiance, 25o C module temperature and AM 1.5). But, a solar PV is going to operate at least 25o C more than STC for 80% of its operation time. One should also understand that module performance should not be judged by ambient temperature but cell temperature and cell temperature is measured back side of PV module.