Photovoltaic module temperature estimation under various environmental conditions: Preliminary experimental and theoretic study

The most of the solar radiation that reaches PV (module is transformed into the heat and partly is transformed into electricity. This causes an increment in the PV module temperature which leads to a decrease in its electrical efficiency. PV module temperature significantly depends on environmental factors such as solar radiation, air temperature and wind velocity. An overview of different empirical models for the estimation of PV module temperature using measured weather data is presented. The obtained results were compared with the measured data of the PV module temperature at the experimental set-up with the aim of preliminary analyzes which empirical model is optimal for analyzed geographical and climate location. Empirical models were evaluated into two categories: models that take into account wind velocity and those that do not. Analyses show that average temperature difference between measured values of the PV module temperature and the values predicted by the empirical models that do not consider wind velocity is 13.37?C and for models that do is 7.40?C. This proves that is very important to consider the effect of wind on PV module temperature. Analyzing obtained data, it can be concluded that temperature of the PV module is above 25 ?C for whole measured period with significant impact of meteorological parameters.