Incremento da eficiência fotovoltaica em painéis solares, por meio de filmes finos antirreflexivos

Abstract

In this thesis, anti-reflective films were developed for application to solar glass in photo voltaic panels. The interest in this topic is due to the fact that photovoltaic solar energy is increasing its share of the Brazilian electricity matrix every day, and projections for the coming years are promising, given that Brazil has regions with high irradiation. However, there are some limitations, such as the panel’s maximum efficiency, which can reach 25%, due to physical limitations, and the energy losses caused by the physical phenomenon of reflection in the solar glass used on the front of the photovoltaic panel, where reflectance can reach 8%. It is possible to reduce this reflectance using anti-reflective thin films, which have been made from the following materials: Al2O3 and a new composition made up of SiO2 BaF2, both synthesised by the sol-gel method and deposited by controlled immersion, which is a low-cost technique, making it a relevant aspect for the research. In order to analyse both the characteristics of the anti-reflective films and their influence on the photovoltaic parameters, the following characterisations were carried out: scanning electron microscopy to analyse the surface of the film and the cross-section to measure the thickness; Uv-Vis-NIR spectroscopy in the transmittance and reflectance modes for the 350 to 1500 nm region of the spectrum; electrical characterisation to obtain the photovoltaic performance of the monocrystalline silicon mini photovoltaic module. The main results obtained for transmittance and reflectance were 96.88% and 3.04% for the Al2O3 film and 96.33% and 3.32% for the SiO2 BaF2 film, respectively. In addition, the photovoltaic parameters obtained were Jsc of 9.96 and 9.72 mA/cm2, with an increase of 8.61 and 6.0%, and PCE of 20.86 and 20.58%, with an increase of 7.66 and 6.19% for the panel covered with the Al2O3 and SiO2 BaF2 films, respectively. The influence of Al2O3 and SiO2 anti-reflective films on photovoltaic parameters is therefore remarkable.