Predição da temperatura operacional das células fotovoltaicas : uma análise dos modelos para as condições do clima semiárido brasileiro

Abstract

Several climatic factors affect the performance of photovoltaic (PV) modules: factors such as solar irradiation, ambient temperature, wind speed are considered to be the most influential. The influence that these factors have on a PV device occurs because they are directly related to the operating temperature of the cells (Tc). This parameter is inversely proportional to the efficiency of PV cells, meaning that the higher Tc, the lower its efficiency. The present work compares the Tc values obtained through measurements and the values obtained through some equations present in the literature that have been developed in the last decades. The measurement of the factors was performed under real operating conditions, with the PV system studied being connected to the distribution grid and subjected to the Brazilian semi-arid climate. Furthermore, based on the collected samples and on generic correlation equations of Tc with meteorological parameters it was possible to develop and propose three prediction models, which were also evaluated. The measurements occurred in the city of Fortaleza-CE, through sensors from the Alternative Energy Laboratory (LEA) of the Federal University of Ceará (UFC) between the years 2018 to 2020. Among the models analyzed, the three models proposed by the present work, Tc ML, Tc MNL I and Tc MNL II, were those that presented the lowest error values, root mean square error (RMSE) around 4.95°C for the first six months of the year (rainy season) and approximately 4.90°C for the last six months of the year (dry season), being the models that presented the best performances. The models developed by Skoplaki & Palyvos, Muzathik and Duffie & Beckman I were the least fit to the behavior of Tc for the climatic conditions analyzed. Duffie & Beckman I presented the highest RMSE values for both the rainy and dry periods of the region corresponding to 16.11 °C and 15.78 °C, respectively.