Thermal Energy Storage Technologies with Thermochemical and Phase Change Materials: A State-of-the-Art Review

This paper presents a comprehensive and state-of-the-art review on thermal energy storage (TES) technologies for building applications comparing thermochemical materials (TCMs) and phase change materials (PCMs) used as storage materials. Both of them enhance the energy efficiency of systems and sustainability of buildings by reducing the mismatch between supply and demand. Many considerations are discussed in this paper including thermochemical storage devices (materials, open and closed sorption, and chemical heat pump), latent heat TES systems (phase change materials and its thermophysical properties). It also classifies available methods of TES and summarizes various experimental, numerical and analytical studies concerning the integration of TES with heat transfer and enhancement techniques over the last several decades. Modelling of TES systems with PCMs and TCMs undertaken using available and engineering types of software such as ANSYS, CFD, ESP-r, Matlab, TRNSYS, etc are reported. Comparison of advantages and disadvantages between thermochemical energy storage systems (TCES) and latent heat thermal energy storage systems (LHTES) are detailed in this review. TES systems using PCMs or TCMs are found to be theoretically attractive since they provide high energy storage densities at a constant temperature. However, both technical and economic questions remain to be answered for their wide scale use. This therefore warrants more fundamental understanding of the PCM and TCM systems particularly the development and large-scale demonstration of TES technologies. The review forms part of current study to investigate in detail the use of PCM and TCM storage systems to store solar energy for applications in buildings.