The Role of Thermal Energy Storage in the Energy System

The increase of the share or renewable energy into the existing power and heating and cooling infrastructure requires overcoming new challenges. Thermal energy storage (TES) and electrical TES bring technical, economic and social opportunities in this new energy system. This chapter explores the use of TES and ETES in all steps of the energy system, generation, transmission and distribution, and demand side. Within the generation side, on top of highlighting advantages and drawbacks compared to other storage systems such as batteries, the successful case of CSP with TES is presented, together with the newer concept of electric TES use in power-to-heat solutions. In the distribution/transmission, TES can be used as support of the smart grid and as support of district heating and cooling systems. Finally, in the demand side, TES can be integrated in buildings (both residential and commercial), in industrial sites, and in smart districts and smart cities.