Improving the performance of a nanofluid-based photovoltaic thermal module utilizing dual-axis solar tracker system: Experimental examination and thermodynamic analysis

Abstract

• A PVT module integrated with a novel solar tracker system (STS) was built. • This STS has two intermittent on/off switching motors for azimuth and tilt angles. • Various coolants and tracking modes were compared using thermodynamic equations. • Results were compared from energy, exergy, and entropy generation viewpoints. • PVT module with STS had 268.24/20.8 W energy/exergy rate higher than fixed PV unit. The purpose of this experimental research is to improve the electrical and thermal output power of a photovoltaic thermal (PVT) module equipped with an automatic dual-axis solar tracker system. The focus of this study is on characterizing the performance of a PV unit and a PVT module both with three different modes of fixed, one-axis tracking, and dual-axis tracking. These modules were installed at the rooftop of the engineering faculty building of Ferdowsi University of Mashhad, Iran. The test fluids are deionized water and silicon carbide nanofluid (SiC/water) with 0.5% and 1% mass fractions. The experiments are executed on non-cloudy days with stable weather conditions during September. The thermodynamic analysis is carried out in terms of energy, exergy, and entropy generation to identify and compare the performance of various modules considered in the experiments. It is found that the proposed nanofluid-based PVT module integrated with the solar tracker system has no significant inverse effect on electrical efficiency thanks to using intermittent on/off switching electro-motors. The results showed that considering the power consumption of the pump and tracking electro-motors when nanofluid-based PVT module (SiC/water 1%) with dual-axis, one-axis, and fixed modes are utilized, the increases in the obtained overall energy (exergy) rates compared to that of the fixed PV unit are 268.24 (20.8 W), 245.91 (16.51 W), and 210.32 (9.64 W), respectively.