In this project, framed within the MSCA-COFUND actions of the Talent4Iberia programme, an innovative approach is proposed based on the use of solid–solid phase change materials (PCMs) as thermal regulators in photovoltaic systems. This strategy not only eliminates the risk of leakage associated with liquid-phase PCMs, but also enables the design of PCMs through crystal engineering to enhance their thermal conductivity. Moreover, since solids are denser than liquids, a smaller PCM volume is expected to be required, which in turn would improve the stability, durability, and overall reliability of the system.