Estudo de desempenho de um sistema híbrido fotovoltaico/térmico

Abstract

The present dissertation presents a performance study of a hybrid photovoltaic / thermal system (PVT system), comparing it with a photovoltaic system (photovoltaic system). The electrical and thermal power, efficiency and energy produced by the systems were analyzed, correlating the influence of the temperature of the photovoltaic module and the electrical efficiency of the systems. The photovoltaic (PV) module used was the MSX 77 of the brand SOLAREX, composed of polycrystalline solar cells, whose peak power is 77 Watts. The PVT system analyzed was of the PVT-liquid type, composed of the MSX77 photovoltaic module and a flat plate type solar collector made of acrylic, the water supply of the manifold was forced by gravity and with open system. To determine the characteristic curves of the PV module and consequently the maximum electric power generated, a load bank formed by power resistors was developed. The thermal power was quantified by measuring the flow of the water that fed the collector and the difference in temperature of the incoming and outgoing water. With the powers and the radiation incident on the systems, the efficiencies were determined. The maximum electrical efficiency reported by the manufacturer of the PV module is 10.8 %, however, under actual operating conditions, the maximum efficiency of the PV module was 8.46 %. In the PVT system, the PV module showed a maximum efficiency of approximately 7.8 % at the point of maximum power generated. The average efficiency of the thermal system was around 42.5 %. The PVT system provided a reduction in the temperature of the PV module, increasing the efficiency of electric generation, providing an increase in the order of 6.9 % in the average daily electric energy. The PVT system, besides providing an increase in electrical energy, still provides thermal energy with a higher efficiency than electric. The heated water can be used to power water heating systems for bathing, contributing to reduce the consumption of electric energy of a residence.