Thermal energy storage options

Thermal energy storage (TES) refers to a collection of technologies that store thermal (heat, hot or cold) energy and use the stored energy either directly or indirectly through energy conversion processes when needed. TES technologies are classified into three categories: sensible, latent, and thermochemical heat storage. These technologies, depending on the material selection and system design, can reach an efficiency over 90%, with an energy density ranging from 0.2 to 3GJ/m3, and an installation cost as low as 0.5€/kWh in applications such as district heating and cooling. TES can be implemented over a wide working temperature range in applications as diverse as power generation, district heating and cooling, building thermal management, the cold chain, and integration with industrial processes. TES systems can be designed for small-, medium-, or large-scale applications (from kWh to GWh) with a system lifetime of over 40 years. This chapter provides an overview of these technologies, covering materials, devices, and applications through to system integration. The chapter also highlights some of the most recent and exciting TES developments, not only in terms of fundamental science but also by considering applied aspects.