Due to climatic change, increasing thermal loads in buildings and rising living standards, comfort cooling in buildings is becoming increasingly important and the demand for comfort cooling is expanding very quickly around the world. The increased cooling demand results in a peak in electrical power demand during the hottest summer hours. This peak presents new challenges and uncertainties to electricity utilities and their customers. Cool thermal storage systems have not only the potential to become one of the primary solutions to the electrical power imbalance between production and demand, but also shift cooling energy use to off- peak periods and avoid peak demand charges. It increases the possibilities of utilizing renewable energy sources and waste heat for cooling generation. Phase Change Materials (PCMs) used for cool storage has obtained considerable attention, since they can be designed to melt and freeze at a selected temperature and have shown a promising ability to reduce the size of storage systems compared with a sensible heat storage system because they use the latent heat of the storage medium for thermal energy storage.