Principle of deep cold compressed air energy storage

What is compressed air energy storage (CAES)?

Compressed air energy storage (CAES) is an effective solution for balancing this mismatch and therefore is suitable for use in future electrical systems to achieve a high penetration of renewable energy generation.

What determines the design of a compressed air energy storage system?

The reverse operation of both components to each other determines their design when integrated on a compressed air energy storage system. The screw and scroll are two examples of expanders, classified under reciprocating and rotary types.

Where can compressed air energy be stored?

The number of sites available for compressed air energy storage is higher compared to those of pumped hydro [, ]. Porous rocks and cavern reservoirs are also ideal storage sites for CAES. Gas storage locations are capable of being used as sites for storage of compressed air .

How does a compressed air energy storage system work?

The performance of compressed air energy storage systems is centred round the efficiency of the compressors and expanders. It is also important to determine the losses in the system as energy transfer occurs on these components. There are several compression and expansion stages: from the charging, to the discharging phases of the storage system.

Where will compressed air be stored?

In a Compressed Air Energy Storage system, the compressed air is stored in an underground aquifer. Wind energy is used to compress the air, along with available off-peak power. The plant configuration is for 200MW of CAES generating capacity, with 100MW of wind energy.

How is energy stored in a low demand space?

In low demand periods, energy is stored by compressing air in an air tight space (typically 4.0~8.0 MPa) such as an underground storage cavern. To store energy, air is compressed and sealed in the space. To extract the stored energy, compressed air is drawn from the storage vessel, mixed with fuel, and then combusted. The expanded air is then passed through a turbine.