Effects of Ambient Air Temperature and Relative Humidity on the Performance of Photovoltaic (PV) Panels

Climatic conditions affect the performance of photovoltaic panels. In this study, the effect of ambient air temperature and relative humidity on the performance parameters of two types of silicon photovoltaic solar panels, including mono-crystalline silicon (mc-Si) and polycrystalline silicon (pc-Si), were studied in the laboratory scale. The experiments were carried out by the performance test lab device environment temperature and humidity control system of solar panels to be fitted. Experiments were conducted at temperatures of 25, 30, 35, and 40 °C and relative humidity levels of 30, 45, 60, and 75%. Characteristic curves of I-V and P-V were determined for various conditions. Performance parameters consist of the open-circuit voltage (Voc), short circuit current (Isc), maximum power (Pmax), maximum voltage (Vmax), maximum current (Imax), and the efficiency. The results showed that humidity and temperature were effective on all operating parameters. An increase in air temperature reduced the whole performance parameters for both panels. An increase in relative humidity from 30% to 45% resulted in an increase in the function parameters, and An increase in relative humidity from 45% to 75% caused a decrease in such parameters. In general, examined in different environmental conditions, the power output decreased from 3.23% to 26.55% for mc-Si solar panel and from 3.07% to 27.14% for pc-Si solar panel- compared to the control condition.