Estudo de viabilidade de aquecimento de água residencial: energia solar fotovoltaica versus aquecimento solar direto

Abstract

This study analyzed the technical and economic feasibility of two solar energy systems for water heating in a rural site: the photovoltaic system with heat pump and the direct solar heating system with collectors. The analysis considered the costs of installation, maintenance, annual savings, and return on investment (ROI) over 25 years, using Net Present Value (NPV) calculations with an interest rate of 11% per year. The photovoltaic system, consisting of 22 panels of 280W, presented an annual saving of R$ 5,040.00, ROI of 7.66 years and NPV of R$ 24,381.42. On the other hand, the direct solar system, with 23 collectors for swimming pools and two collectors for showers, generated annual savings of R$ 2,600.00, ROI of 6.2 years and NPV of R$ 10,600.62. Although the PV system is more comprehensive in terms of energy application, the direct solar system has demonstrated greater initial economic viability due to the lower investment required and the faster financial return. Both systems are energy efficient and contribute to sustainability and the reduction of electricity consumption in the long term.