Compressed air energy storage technology is an energy storage technology that converts mechanical energy into electrical energy. Its principle involves compressing air into high-pressure gas, storing it in a storage tank, and then releasing the compressed air through the reverse process when a downstream load needs electricity, driving a turbine/generator set to generate electricity.
Specifically, compressed air energy storage systems typically include the following components:
1. Air compressor: Used to compress air from atmospheric pressure (about 1 bar) to very high pressure (usually 100-300 bar) in order to store more energy in the air tank.
2. Gas storage tank: Used to store compressed air and maintain it under high pressure without leakage. Gas storage tanks can be underground gas storage facilities or large gas tanks.
3. Expander/Turbine: Used to release stored compressed air and convert mechanical energy into electrical energy. Common turbine types include turbines and expanders.
4. Generator: Used to convert mechanical energy into electrical energy.
The main characteristics of compressed air energy storage technology are as follows:
1. High controllability: The gas storage tank can store different amounts of energy as needed, and the system's output power can also be adjusted according to demand.
2. High efficiency: The energy conversion efficiency of compressed air energy storage systems can reach 70%-85%, which is higher than that of traditional batteries.
3. Easy to maintain: Compressed air energy storage systems are composed of simple mechanical parts, making them easy to maintain and repair.
4. Environmental protection: Compressed air energy storage systems do not produce harmful gases such as carbon dioxide during operation, making them a relatively environmentally friendly energy storage technology.
5. Multifunctionality: Compressed air energy storage systems can be used in conjunction with renewable energy sources such as wind power to help eliminate fluctuations in unstable power sources and improve grid stability.
Compressed air energy storage also has some obvious drawbacks. On the one hand, there are issues with thermal management, and on the other hand, the energy density is relatively low and the energy loss ratio is relatively high, making it difficult to miniaturize and apply. It can only be used as a low-demand energy application.
