Thermal control of crystalline silicon photovoltaic (c-Si PV) module using Docosane phase change material (PCM) for improved performance

Abstract

As crystalline silicon photovoltaic (c-Si PV) module demonstrates circa 0.45% drop in conversion efficiency for every 1 °C cell temperature rise above 25 °C standard test condition (STC), thermal control of the system is critical to improving its efficiency especially for elevated temperature climate deployment. This research demonstrates the utilisation of Docosane C22H46 paraffin wax phase change material (PCM) to lower the operating temperature of c-Si PV module operating in hot climatic conditions. Employing computational fluid flow fluent analysis in Ansys software package, the thermal responses of finite element (FE) models of the module to environmentally induced loads are simulated for 24-hour period. The results are validated analytically. Findings reveal that temperature difference between ambient and solar cell is maximum at noon at 23.7 °C and monotonically decreases afterwards to zero at 6.00 am and 8.00 pm. The implementation of PCM delivers a PV-PCM module that is 10.88% more conversion efficient than the conventional c-Si PV module. Further findings show the improved efficiency results from PV-PCM module achieving cell temperature reduction of 78.4% at peak heat flux and 31.1% overall. The PV-PCM module produces 6.1% more voltage, 2.1% more electric power and 8.1% more maximum power daily than the conventional c-Si PV module. In addition, it is found to be 1.05% more efficient and has 34.0% longer fatigue life. The PCM usage demonstrates effectiveness in control of thermal characteristics of c-Si PV module by improving its performance – crucial for its reliable operations in hot climates.