Estudo da viabilidade financeira de um sistema fotovoltaico conectado à rede em orientação desfavorável e sujeito à sombreamento parcial

Abstract

The use of Grid-Connected Photovoltaic Systems (Grid-tied) has increased every year. There are several factors that explain this growth, worth highlighting: increasing the cost of electricity due to constant tariff adjustments, reducing Grid-tied prices and increasing the efficiency of electrical conversion by the systems. Among the possible applications of Grid-tied are urban installations, whether on slabs, facades or roofs. Installations in urban environments, however, can be negatively affected, mainly due to non-ideal orientation and the occurrence of system shading. In this work, 3D modeling was carried out of a Grid-tied integrated into a roof in an urban environment with a non-ideal orientation and subject to shading. Simulations were carried out using the PVsyst software, with 3D modeling assisted by the SketchUp software. Actual Grid-tied installation conditions were compared to hypothetical scenarios that changed the shading source, roof orientation, and module distribution configurations at the inverter's MPPT inputs. The combination of studied scenarios resulted in 18 simulations. The results obtained showed that, comparing the worst hypothetical scenario, which involves non-ideal orientation and a high source of shading, in relation to the best possible scenario, with no shading and orientation to the north east, the Grid-tied presents a loss of electrical production of 227.36 kWh in the first year and 4,304.76 kWh in the project's cumulative total, resulting in a loss of revenue of R$ 6,352.72 over the project's time horizon (20 years), representing a 3.217% reduction in expected revenue. The indicators for the simulation with the real installation characteristics were: NPV of R$ 43,451.07, IRR of 42.16% and Payback of 3.48 years. For this specific installation, the occurrence of shading and the use of non-ideal orientation are not factors that make the project unfeasible. The present study, however, does not allow generalization to other cases, making an individual analysis of the system installation conditions necessary.