Influências na geração de energia elétrica em módulos fotovoltaicos revestidos por policarbonato alveolar e compacto

Abstract

There is growing interest in investing in the generation of own electric energy, especially that coming from the solar photovoltaic source, also, but not in the same intensity, the interest in integrating the photovoltaic systems to the buildings grows, being one of the commercial solutions available the one that uses the polycarbonate with flexible photovoltaic modules, a solution that allows the creation of curved photovoltaic surfaces, which gives more freedom in the integration of the building architecture. However, there are possible impacts that tend to reduce system efficiency, such increasing the temperature of photovoltaic cells and reducing the solar irradiance that reaches these cells. So in this study, an experimental roof was built, with a photovoltaic module installed in the conventional way, over the roof, and six other modules installed in an integrated to the roof way, on the inner side and covered by multiwall and solid polycarbonate. The temperatures were monitores, as the external and inner ambiente and back of the modules temperatures, also the energy generated by each of the modules and incident solar irradiance in the same plane of the modules. At the end, it was verified that, in a comparison between the two installation formats (traditional and integrated), the module installed in the traditional way presented the highest efficiency, while the module fixed under the compact polycarbonate generated about 27% less electric energy than the module over the roof. Concerning the multiwall polycarbonate, the modules fixed under the vertically oriented multiwall polycarbonate presented the worst performance among all, while the modules fixed under the horizontally oriented multiwall polycarbonate presented a slightly better performance, but still far from those fixed under the solid polycarbonate. Regarding the temperatures, the module fixed over the roof presented the lowest temperatures and lower thermal amplitudes, the module under the vertically oriented multiwall polycarbonate presented the highest temperatures and thermal amplitudes, followed by the module under the multiwall polycarbonate oriented horizontally, and the module module fixed under the solid polycarbonate. The electrical energy generation loss caused by addition of the polycarbonate was higher than 1/4 in relation to the system installed in the conventional way, not to mention that there was greater accumulation of dust on the polycarbonate’s sheets than on the module covered by glass. Thus, the use of polycarbonate seems to be interesting only in installations where integration requires curved surfaces, otherwise the best solution is to use the photovoltaic module itself integrated with the building, without the addition of other materials on its surface.