Review of PCM types and suggestions for an applicable cascaded PCM for passive PV module cooling under tropical climate conditions

Abstract

The phase change material (PCM) based cooling systems have gained recent popularity with PV module temperature (TPV) reduction and enhanced performance. The technology is confined with the spacious demerits like physical contact, conductivity and PCM melting temperature (Tmelt) loss. It is found that PCM Tmelt loss is higher than other losses and in most of the cases examining single PCM is not effective throughout the year. In this study, two different tropical and one sub-tropical conditions are selected to analyze the variations in TPV with respect to extremely varying climatic conditions. Pearson’s correlation method is adopted and analyzed to determine the dependence of TPV on the ambient temperature (Tamb) for summer and winter. It is noted that for the selected tropical climate in Thailand, 33 °C of Tamb in winter causes the TPV to rise to 60 °C emphasizing the need for cooling system even in winter. So cascaded PCM is selected for Thailand. The first layer of the PCM (PCM-A) has a lower Tmelt within the range 36–39 °C and the second layer is a higher Tmelt (PCM-B) within the range 44–47 °C. During winter, PCM-A turns active, following which PCM-B assists in maintaining a lower PCM-A temperature, and for summer both PCM layers will be effective in operation. Based on the proposed PCM Tmelt optimization, the tropical climate in India and sub-tropical climate in France do not require PCM for cooling in winter, but for summer it is necessary within the ranges 44–47 °C and 31–34 °C, respectively. The study highlights the need for adopting different PCM-based systems depending on the location/climatic conditions.