Thermal performance of solar photovoltaic panel in hot climatic regions: Applicability and optimization analysis of PCM materials

Abstract

A numerical modeling methodology based on the finite element method is utilized in this investigation to predict the impact of the PCM characteristics on the system cooling performance and the solar module output power. The thermal analysis considers the transient nature and the nonlinearity of the problem. The boundary conditions include the cyclic variation with time of solar irradiance and ambient temperature in a hot climatic region, with peak temperatures close to 50 °C. Under these circumstances and owing to the various influencing parameters, choosing an appropriate PCM is a challenging task. By allowing the PCM characteristics to vary continuously over the applicable domains and not just by giving specified discrete values, a systematic approach is adopted in this work. This technique is applied to explore the relationships between system input parameters, as defined by the PCM properties, and output variables, as described by cell temperature and module efficiency. Due to the harsh boundary conditions, the obtained results demonstrated that PCM with high thermal conductivity is required to achieve efficient thermal regulation. The enhanced material characteristics can only be provided by composite PCMs with graphite or metal additives. The resulting optimized design variables of the suitable PCM, melting temperature, thermal conductivity, and thickness, can reduce the cell temperature to 57 °C (20% reduction). The corresponding efficiency and power output are raised by around 8%. The power output was found to increase from 125 W (reference case) to 135 W for the optimized case. The results suggest that using a passive cooling system based on PCM is a viable method for enhancing the power output of a solar PV module. The created coupled model predicts the thermal behavior of the PV module and significantly facilitates the PCM selection procedure to ensure its applicability.