Phase Change Materials for Thermal Energy Storage

Salt hydrate phase change materials used for thermal storage in space heating and cooling applications have low material costs, but high packaging costs. A more economic installed storage may be possible with medium priced, high latent heat. Latent heat storage is one of the most efficient ways of storing thermal energy. Unlike the sensible heat storage method, the latent heat storage method provides much higher storage density, with a smaller temperature difference between storing and releasing heat. This paper work on latent heat storage and provides an insight to recent efforts to develop new classes of phase change materials (PCMs) for use in energy storage. There are large numbers of phase change materials that melt and solidify at a wide range of temperatures, making them attractive in a number of applications. Hydrated salts have larger energy storage density and higher thermal conductivity but experience super cooling and phase segregation, and hence, their application requires the use of some nucleating and thickening agents. Sodium carb-onate, sodium phosphate and sodium sulfate tested as phase change material by crystallization in this work.