Recent progress, design characteristics and future directions of thermal energy storage technologies

Abstract

Thermal energy storage (TES) technologies have gained significant traction across academic and industrial domains due to their capability to capture and subsequently release thermal energy with high throughput and efficiency. TES technologies are classified into sensible heat storage (SHS), latent heat storage (LHS), and thermochemical storage (TCEs). Despite their increasing uses in various applications such as district heating and cooling, and solar power, their efficiency depends on a variety of technical, economic and environmental factors.  This review presents the recent development in TES technologies with emphasis on their technical, economic, and environmental implications. It also examines and compares these TES systems in terms of their designs, mechanisms, applications and suggests the optimal system for sustainable energy storage. More importantly, it addresses the recent challenges, opportunities and solutions to attain high performance TES devices with emphasis on material or medium selection, technical, economics, environmental and the uniform thermal characteristics. This critical review utilizes a structured design approach to collect the relevant data from Scopus database and analysed the TES technologies in terms of their designs, operation mechanisms, technical, economical and environmental implications. LHS and TCES have higher energy density and offer various benefits as discussed in this review, but the material selection and complex design, especially for TCES systems, hinder their transition from laboratory-based to industrial and scalable production. LHS based PCM nanomaterials (e.g. graphene, carbon, metallic and their hybrids) are anticipated to revolutionize the TES industry. This review is appealing to both researchers and engineers in the field as it provides the recent progress, mechanisms and future directions on TES technologies. Future studies should focus on developing integrated systems that integrate the high-density materials of LHS (e.g., PCMs) with the SHS and TCES systems to achieve reliable and robust TES system.