ABSTRACT

Compressed air energy storage (CAES) is described in this chapter, from some historical realizations to advanced technologies.

The elementary principles and properties are described, with the strategy of isothermal compression and expansion in the foreground. The general characteristics of adiabatic, poytropic, and isothermal characteristics are compared, as well as the single-stage and multiple-stage machines. The concept of the liquid piston is introduced, as well as an original concept of the so-called finned piston.”

A medium-scale hydropneumatic storage system is described, using a closed gas cycle with water injection. Finally, a new underwater CAES system is described, using immersed expandable energy bags. The system has the property to be operated with constant pressure at the level of the compression/expansion machine, and also for the storage reservoir.

In the sector of sustainable mobility, a compressed air car is introduced.

The chapter is completed with didactic exercises, facilitating the understanding of the CAES principles.