A Cost-Effective and Efficient Electronic Design for Photovoltaic Systems for Solar Hot Water Production

Abstract

A significant percentage of energy consumption in buildings is to produce hot water. Photovoltaic solar heating can be considered a clean and renewable energy option—easy to install, silent, and without maintenance—to replace the consumption of fossil fuels used in this process. This paper presents a study that simulates the heating process using thermal electrical resistors powered by photovoltaic solar energy. For this purpose, a solar hot water installation has been set up. This installation consists of a water tank with an electric resistance connected to photovoltaic modules by means of a low-cost experimental electronic conversion system. This electronic system has been developed to avoid the need for inverters or batteries, typical of traditional photovoltaic solar installations. It is an isolated system since it is not connected to the power grid. The photovoltaic solar modules, the tank, and its heating resistance correspond to commercial models. This electronic system has a 95.06% yield, and it operates across the whole irradiance’s daily curve, having verified its operation over several months. Even though this is an experimental electronic device, it is financially viable as the cost of its components is below EUR 60 per kW peak capacity. The results obtained in a proper functioning system are promising, demonstrating the technical feasibility and economic advantages of using this type of isolated photovoltaic system to power heating processes.