Field Testing of Electrical and Thermal Performance of Photovoltaic Modules Cooled with Phase Change Materials

The efficiency of photovoltaic (PV) modules significantly decreases under high operating temperatures, motivating the exploration of passive cooling strategies to enhance their performance in real outdoor conditions. This paper presents a field-based experimental evaluation of the thermal and electrical performance of PV modules integrated with phase change materials (PCMs). Three salt-hydrate PCMs, with melting temperatures of 18∘C,29∘C, and 48° C, were applied to monocrystalline silicon PV modules and tested against a reference module without PCM at the SolarTech LAB of Politecnico di Milano. Over a 47-day monitoring period, the system's thermal behavior, electrical output, and PCM phase transition dynamics were systematically analyzed using high-resolution sensors and thermographic imaging. PV-PCM48 achieved the best thermal and electrical performance, followed by PV-PCM29. In contrast, PVPCM18 showed a slight thermal penalty and reduced electrical output, confirming the importance of aligning PCM properties with climatic conditions. Additionally, correlations between the electrical power, temperature, and heat flux were characterized to support the thermal modeling of PV-PCM systems in future research. The results of the thermographic analysis confirmed the critical role of PV-PCM assembly and PCM selection and thermal matching to environmental conditions, as improper melting dynamics or encapsulation geometry can lead to suboptimal heat dissipation and reduced performance benefits.