Thermo-electrical performance enhancement of photovoltaic / phase change material systems using copper foam matrix with multi-walled carbon nanotubes additives

Abstract

Like all other semiconductor devices, photovoltaic (PV) panels are sensitive to temperature. High temperature reduces the bandgap of a semiconductor, thereby increasing the energy of the electrons in the material. The panels’ temperature can be reduced using phase change material (PCM), which works as a passive cooling material to absorb heat at a low tilt angle. To further improve the panel’s temperature, copper foam matrix (CFM) can be used as an additive to the PCM to enhance its thermal conductivity. The compound’s thermal performance can be further enhanced by adding high thermal conductivity materials such as Multi-Walled Carbon Nano- Tubes (MWCNT), however, no report has been published in the literature. Therefore, this study aimed to investigate the effects of the PCM/CFM materials on PV panel temperatures and their electrical performance. The study consisted of two parts, numerical analysis and experiments. The numerical analysis was carried out using ANSYS FLUENT 15.0 to predict and simulate the convection heat transfer mechanism inside the passive cooling container. The experimental part was investigated the unpredictable measurements, such as the enhancements in the electrical efficiency of the PV panels made of the proposed passive cooling materials. Temperature of the panel was measured to validate the numerical simulation. Based on the findings, when the PCM was used, decreasing the PV tilt angle from 90° to 0° will increase the PV cell’s temperature from 0.4% to 12%. It also decreases the corresponding cell’s electrical efficiency from 5% to 0.2%. Whereas, when the CFM was added to the PCM, the PV cell’s temperaturewas reduced further by 10.43%, and increased the cell’s electrical efficiency from 1.79% to 4.5% at a tilt angle of 30°. When MWCNT with a weight concentration ratio of 0.20% was added in the PCM, it further improved the PV cell’s temperature and the electrical efficiency by 2.86% and 5.68%, respectively, due to the enhancement of the PCM’s thermal conductivity. The improved PV panel was verified by experimental works under actual weather conditions, and it was found that the PV panel electrical efficiency improved by 21%. These findings indicate that using CFM with 0.2% ofMWCNT additives within PCM, is an efficient method for electrical performance improvement in PV panel applications passively at low tilt angles.