**3.1 The PCM supercooling**

Supercooling occurs when a phase change material (PCM) like water does not solidify at its equilibrium freezing point, staying liquid even below this temperature due to the absence of nucleation sites, which are necessary for phase change initiation. This state hampers the PCM's ability to store and release thermal energy efficiently, impacting the effectiveness, reliability, and performance of thermal energy storage (TES) systems. The degree of supercooling is influenced by factors such as impurities and surface conditions. To counteract supercooling, strategies like incorporating nucleators, using gelling agents, and applying the Cold Finger Technique are employed, enhancing the operational efficiency of TES platforms [75].
