An Overview of Thermal Energy Storage (TES) Materials and Systems for Storage Applications

This paper presents an overview of thermal energy storage (TES) materials and systems for storage applications. A TES system is composed of a storage medium (TES material), a heat exchanger and a storage tank. TES systems employ storage technology by heating/cooling a medium so that the stored energy can be used later in various applications. In recent years, TES systems have attained significant interest in the scientific community, finding multiple applications in air heating/cooling, water heating, buildings, and more. TES systems depend on capacity, power, efficiency, storage period, and cost. TES systems are divided into three main categories, depending on how the energy is stored: sensible systems (with hot water), systems using phase change materials (PCMs), and systems based on chemical reactions. Among these three types, PCM-based systems are outstanding in terms of both performance and cost-effectiveness. These advanced materials contribute to the conservation of heat and solar energy, as well as improving their efficient use. This paper addresses different aspects of PCMs utilization. The classification of PCMs is based on the thermophysical properties of composite PCMs, their methods of production, the main challenges associated with them, and the solutions to these challenges. The progress in creating more efficient TES systems and finding the appropriate PCMs is also reviewed.