Evaluation of three systems of solar thermal panel using low cost material, tested in Brazil

Residences in Brazil consumed much energy through water heating systems. The electric shower uses most energy of the electric power system, and the main source of energy is hydroelectricity, which depends on climatic variations. To minimize the pressure on the electrical system by water heating, an alternative use of solar thermal water heating panels is needed. The objective of this study is to evaluate three different types of low-cost solar thermal panels: PET bottles, PVC lining and aluminum cans. The experiments were carried out in Cascavel-PR, campus of State University of Western Paraná. The collection of temperature data was simultaneously carried out in the three systems, using a PT100 sensor, with hourly readings from 10 to 16 h, for 30 days. Solar radiation data on the period were provided by SIMEPAR. After the collection and data analysis, it was found that the system with aluminum cans showed the best performance reaching 54.3 °C, presenting an efficiency of 41.6%. Thus, for these experimental conditions, this system is recommended for use in residential water heating to reduce the electric bill.