An in-depth thermo-electrical evaluation of a rooftop PV technology for a residential building using advanced infrared thermography

Abstract

The investigated performance criteria of photovoltaic (PV) modules in the studies have been limited to current, voltage, power, and temperature. It means that a study with the aim of a comprehensive investigation of a number of key thermo-electrical indicators of the system, namely, photocurrent (Iph), parallel resistance (Rp), thermal voltage of diode (Vt), and diode reverse saturation current (I0), has not been done yet. Considering this point, a PV system installed on the roof of a residential building in Tehran, Iran, is experimentally studied here. For this system, the data gathered during a year is employed to find the values of the four indicated thermo-electrical characteristics. In order to enhance the accuracy, advanced infrared thermography is utilized, in which the photos taken by the thermal imaging camera is processed with developed code on the MATLAB interface. The results show that thermo-electrical indicators of the PV system change significantly throughout the year. With 32.3%, Vt is the indicator with the lowest annual variation. Rp and Iph change 1004.1 and 1943.9%, respectively, as well. Moreover, the simultaneous application of cooling techniques and concentrating strategies is suggested as a very efficient way to enhance the system performance.