Análise econômica da implantação e utilização de sistemas de aproveitamento de energia solar e de águas pluviais em uma residência unifamiliar

Abstract

In Brazil, sustainable buildings are still somewhat debated topic, which hinders the insertion of new construction methods and use of new technologies. The solar heating and rainwater utilization water are not new technologies, but their use has been spreading gradually, which put them among the most popular among sustainable solutions applied in construction. For lack of incentive, the system of photovoltaic power generation in Brazil is still far from motivating people to adopt it in residential projects, for this reason, the present work is to present the features and operation of the three most popular systems (solar heating, power generation through photovoltaic panels and rainwater harvesting), and, based on designs of a specific home, provide for the installation of the first two, running survey of costs involved in both, and predicting the economies (income) generated by each. Following with the data collected, there was an economic analysis by considering the effects of inflation and a hurdle rate (equivalent to the savings accounts) where calculated return indicators (VPL, VPLa, IBC and ROIA) were and risk indicators (TIR, payback, TMA / TIR and payback / N ratio) of the project, which allowed us to assess the economic viability of ourselves as an investment project. The result showed that the use of solar heating system is not a viable option when used alone, however, the system utilization of rainwater, in the analyzed case had one as soon feasible positive return. Analyzing the joint installation of both systems, we found that you can recover the capital invested without taking high risks.