Thermo-economic Study of Phase Change Materials (PCMs) for Thermal Energy Storage

Abstract

Thermal energy storage in the form of latent heat using phase change materials (PCMs) provides the advantages of high energy storage density and isothermal storage and retrieval behaviour. The thermal properties of PCMs are important in deciding the space requirement, heat exchanger design and its applicability with a given thermal energy source. Another important factor is the price of PCM, which limits certain materials from being used due to the high costs involved. Hence, a comprehensive evaluation of the thermal and economic aspects of PCMs would serve in making proper choice of energy storage material. This paper presents thermo-economic analysis of PCMs and estimations on energy storage densities and the cost of storage per unit of thermal energy stored. It was observed that NaOH and CaCl2.6H2O having thermal capacity of 106.85 and 100.53 kWh/m3 and low storage cost of 1.76 and 0.69 $/MJ, respectively, make them a good choice for energy storage.