Thermal energy storage can be subdivided into different technologies such as storage of sensible heat, storage of latent heat as well as thermos-chemical and absorption storage. Low-temperature thermal energy storage can be operated below 200°C and is mainly applied to heating and cooling of buildings and district heating and cooling (DHC) using waste heat from different sources or renewable energy sources.
High temperature thermal energy storage plays an important role in the integration of renewable energy sources, first of all the concentrated solar power (CSP) in the energy systems and in the recovery of high-temperature waste heat from industry. According to the length of time for which the thermal energy must be stored, systems can also be divided into ‘short-term’ (seconds-minutes) and ‘long-term’ (hours-seasons) energy storage.