Introduction  As a long-term energy storage form, compressed air energy storage (CAES) has broad application space in peak shaving and valley filling, grid peak regulation, new energy consumption, auxiliary services, and other aspects, which is of great significance for accelerating the construction of a new power system with new energy as the main body in the context of "carbon peak & carbon neutrality".

  Method  Firstly, current status of CAES were analyzed and summarized from the principles and technical classifications. Then, based on the current technological development, a creative solution of CAES was proposed by China Energy Engineering Corporation Limited, which includes the "medium temperature adiabatic compression" technology route for high-pressure hot water heat storage and the "high temperature adiabatic compression" technology route for low melting point molten salt and hot water combined heat storage. The key technical points, such as system integration and optimization, equipment selection, heat storage medium, gas storage equipment, and digital network storage coordination, have been introduced. Finally, engineering cases were introduced around the two technical routes.

  Result  The results indicate that, in order to improve the conversion efficiency of power plants, it is necessary to comprehensively consider the material flow and energy flow coupling characteristics of various systems, such as compressor system, turbo-expander system, heat storage system, and gas storage system, and then develop the key equipment such as compressors, turbo-expanders, heat exchangers suitable for compressed air energy storage, as well as key technologies such as underground gas storage and grid storage coordination.

  Conclusions  The research can provide scientific reference for the subsequent development of CAES.