CautiousSlug (@CautiousSlug)

Energy storage knowledge: What is compressed air energy storage? Compressed air energy storage system: The compressed air energy storage system is a system that uses high-pressure air pressure energy as a form of energy storage and generates electricity through the expansion of high-pressure air when needed. The working process of this system can be divided into two parts: energy storage and energy release. 1) Energy storage link: The compressed air energy storage system uses wind/photovoltaic or low valley electric energy to drive the compressor and convert electric energy into air pressure energy. The high-pressure air is then sealed and stored in abandoned mines, caves, abandoned oil wells or man-made gas storage tanks; 2) Energy release link: By releasing high-pressure air to drive the expander, the stored air pressure energy is converted into mechanical energy or electrical energy again. Traditional compressed air energy storage systems need to burn fossil fuels in the combustion chamber to heat the air during the energy release stage to achieve the function of using air to generate electricity. The development of traditional air energy storage technology is limited, and there is limited room for efficiency improvement. Traditional compressed air energy storage systems rely on fossil fuels and large air storage chambers, and the system efficiency is low. For example, the efficiency of the Huntorf compressed air energy storage power station in Germany is only 42%, and the energy efficiency of the Mcintosh power station in the United States is about 54%. Their development and application are limited. At present, the most important new compressed air energy storage systems mainly have three new technical paths. Thermal compressed air energy storage (TS-CAES), liquid compressed air energy storage system (LAES), supercritical compressed air energy storage system (SC-CAES). 1) Thermal compressed air energy storage (TS-CAES): The air compression process will generate compression heat, in traditional compressed air energy storage. This part of the heat is usually taken away by the cooling water and eventually dissipated, while the regenerative compressed air energy storage stores this part of the heat during energy storage. When releasing energy, this part of the heat is used to heat the air at the inlet of the expander, realizing energy recycling and improving system efficiency. At the same time, due to the heating of compression heat before the expander, the combustion chamber can be eliminated, which means that the system also gets rid of its dependence on fossil fuels. 2) Liquid compressed air energy storage system (LAES): With the help of air cooling and liquefaction technology, air is stored in liquid form through the addition process. When storing energy, the high-pressure air passing through the compressor enters the regenerator cooling and decompression equipment for liquefaction, and the liquefied normal-pressure low-temperature liquid air is stored in the liquid storage tank. When releasing energy, the liquid air is boosted by the cryogenic pump and heated by the regenerator, and then enters the combustion chamber, mixes with fuel, and then enters the expander to expand and perform work. 3) Supercritical Compressed Air Energy Storage System (SC-CAES): Utilizes the supercritical characteristics of air to efficiently transfer heat/cold during the heat storage/cold process, and store the air in liquid form. Achieving the advantages of high system efficiency and high energy density, the system has the characteristics of thermal storage and liquid compressed air energy storage, while getting rid of the problem of relying on large air storage chambers and fossil fuels. Regenerative energy storage is expected to be commercialized on a large scale in the short term, and supercritical technology has a bright future, which may further improve system efficiency. Taken together, thermal storage does not rely on fossil fuels, has high efficiency, and has relatively mature technology. We believe that it has begun to meet the conditions for large-scale commercialization. China has a large number of salt caves and abandoned mine caves, and using existing caves to build low-cost compressed air energy storage systems has great development prospects. Thermal compressed air energy storage is expected to achieve large-scale commercialization in the next few years, further reducing costs. Supercritical, on the other hand, has the advantages of both liquid and thermal storage, and has a brighter future. After technological breakthroughs, the system efficiency of compressed air energy storage is expected to be further improved. https://www.huntkeyenergystorage.com/compressed-air-energy-storage/