A TES system normally consists of a storage medium in a reservoir/tank, a packaged chiller or built-up refrigeration system,
piping, pump(s), and controls. Based on the range of operating temperature, TES can be classified into two groups: low-temperature TES (consisting of aquiferous low-temperature TES and cryogenic energy storage) and high- temperature TES (including latent (fusion) heat TES, sensible heat TES and concrete thermal storage).