Cryogenic Energy Storage

Cryogenic Energy Storage (CES) refers to a technology that stores energy in a material at a temperature significantly lower than the ambient temperature. The storage material can be a solid (e.g., rocks) or a liquid (e.g., salt solutions, nitrogen, and air). This chapter specifically deals with the CES that stores energy in a cryogenic fluid with the fluid also acting as a working fluid for power generation. The concept, the process and the recent development in the area are introduced first with liquid air based CES as an example. A thermodynamic analysis is then briefly described on a standalone liquid air based CES system. The use of cryogen as an energy carrier for renewable energy transmission as well as versatile services is illustrated using examples including as peak-load shifting, black start, frequency regulation, cold chain transportation, and ammonia synthesis.