Thermal Modeling of Photovoltaic Panel for Cell Temperature and Power Output Predictions under Outdoor Climatic Conditions of Jodhpur

The rise in the temperature severely affects photovoltaic cell efficiency and hence its power output. Moreover, it also causes the development of thermal stresses that may reduce their life span. Thus, there is a need for an accurate estimation of the cell’s working temperature. In this paper, a detailed thermal model based on various heat transfer modes involved and their governing equations has been presented to estimate the cell temperature of a PV module using MATLAB software under different climatic and solar insolation conditions. In order to validate the presented model, an experimental setup has been built and operated under actual outdoor conditions of Jodhpur, a city in the Thar Desert of Rajasthan. For the peak summer month of June, the predicted glass cover outer surface temperature has been found to be within 0.2–4.5°C of experimentally measured values and the back sheet temperature is found to be within 0.5–5.5°C. The predicted and measured power outputs have been found to be within 0.85–1.2 W while the efficiency values are within 0.17–0.38%. For the early summer month of April, the variations are 0.13–4.1°C, 0.2–4.1°C, 0.44–1.65 W, and 0.1–0.5% for glass cover temperature, back sheet temperature, power output, and efficiency, respectively. Thus, the predictions of the developed thermal model have exhibited a good agreement with the experimental results. The maximum glass cover temperatures recorded were 60°C and 65.5°C when the ambient temperatures were 35°C and 42°C near the noon for the early summer and peak summer day experiments, respectively. The presented model can be used to generate a year-round cell temperature data for the known environmental data of a location, which can help in the selection or development of appropriate cooling technology at the planning stage of the installation of a solar PV plant.