Modelo elétrico-térmico para representar o comportamento de módulos fotovoltaicos flutuantes em água a partir das condições climáticas do semiárido brasileiro

Abstract

This thesis deals about a study developed at the Laboratório de Energias Alternativas (LEA) - UFC to verify the electrical-thermal behavior of floating crystalline silicon photovoltaic modules on water. So, experiments using three (03) PV modules, 01 water tank, 01 commercial I-V curves tracer, 01 second class pyranometer and 01 anemometer were developed. Styrofoam frames were used to float the PV modules on water. The temperature was measured at three different points of the modules to obtain an average between their values, representing the PV module temperature. From a linear regression analysis, a correlation to determine the module average temperature was proposed. After this stage, two correlations to determine the efficiencies of floating PV modules on water were developed analytically. Reductions of the operating temperature of the PV modules as well as gains of conversion efficiencies up to 18% were observed. The tests with the PV modules in contact with water showed some problems to be faced, such as infiltration on their front surfaces and in the contact boxes, shading on the cell due to the frames edges and no displacement of water accumulated in front surfaces in rainy days. An electrical-thermal model was developed with the use of MATLAB / SIMULINK in order to physically represent the generation behavior of floating PV modules. This model allowed I-V curves to be drawn from the values of some input parameters, namely the incident irradiance on the horizontal plane, ambient temperature, water temperature and wind speed, as well as other reported by manufacturers technical data sheets (short-circuit current, open circuit voltage, current and voltage at the maximum power point, temperature coefficients and modules area). As the final stage, PVSyst program was used to develop a power generation scenario of a floating PV plant over the waters of Castanhão reservoir, in the state of Ceará, which would provide the service of 5% of the electricity demand of Fortaleza and 2% of the demand of the state of Ceará.