Comparative Experimental Study of PCM and Zeolite-Based Passive Cooling for Enhancing Second Generation Solar Panel Performance in Hot-Arid Climates

Operating at high temperatures is one of the key factors affecting the performance of photovoltaic systems. In hot-arid climates, the temperature is typically extremely high. In this study, the experimental performance of two passive cooling systems, phase change materials (PCMs) and zeolite X13-CaCl₂, was comparatively assessed to improve the performance of cadmium telluride photovoltaic panels under the same real operating conditions in Baghdad, Iraq. An improvement of approximately 8.5% in electrical conversion efficiency (i.e., the percentage increase compared to the reference system and not the actual value) was achieved, with a decrease in temperature of approximately 12 °C being recorded from the use of PCM. On the other hand, the temperature decreased by 15 °C in the case of zeolites, with an improvement in the relative efficiency of approximately 10.2% compared to the reference system. In addition, there was an improvement of approximately 23.8% in energy production when the PCM was used. However, there was a greater improvement of approximately 33.1% in energy production when the zeolite system was used. The results of the zeolite system were better than those of the PCM system because the zeolite system had a higher thermal storage capability owing to its porous nature. The phase change only occurs in the range of certain temperatures in the PCM system.