Temperature measurement of solar module in outdoor operating conditions using thermal imaging

In this paper, a method to determine the operating temperature of photovoltaic module in outdoor conditions using thermal imaging is presented. Importance of temperature in PV module performance is well known at design and monitoring level. As manufacturer provide module specifications at STC (25 °C, 1 KW/m2) and the outdoor conditions are different, so in order to know the change in actual output of PV module and to track maximum power point with temperature in real time, it is important to determine the exact temperature of PV module in outdoor operating conditions. Existing techniques to determine the OOT have many drawbacks as discussed in paper. To overcome those drawbacks, a non-invasive and more accurate technique is suggested to measure module temperature in operating conditions. An experimental setup was established in outdoor and infrared images of PV module were captured using a Flir Infrared camera. These images were further processed quantitatively to calculate the temperature of module. To validate the results, actual field output data was compared to values calculated with the help of well-established relations available in literature at different temperatures calculated using existing techniques. Parameters calculated using thermal imaging method were most nearer to the actual field output data.