On October 3rd, Sichuan Online reporters learned from Dongfang Electric Corporation that its EPC-contracted national demonstration project, the Huadian-Dongfang Electric Mulei Compressed Carbon Dioxide Energy Storage Comprehensive Energy Demonstration Project, has successfully connected to the grid and begun generating power in Mulei, Xinjiang. The project is China's first 100-megawatt-scale compressed carbon dioxide energy storage project, having established the complete process chain of carbon dioxide compression, liquefaction, storage, gasification, expansion, energy release, and power generation, achieving a major breakthrough in China's gas-liquid phase change energy storage key technologies and engineering-integrated applications, further enriching the domestic long-duration energy storage technology system and providing a replicable and promotable engineering model for supporting energy storage at large-scale wind and solar bases in desert and gobi areas.
This giant "power bank" located on the gobi desert can achieve flexible storage and discharge according to grid demand, charging during low-demand periods and discharging during peak periods. China's first 100-megawatt-scale compressed carbon dioxide energy storage project. Image courtesy of Dongfang Electric Corporation.
During low electricity demand periods, it uses surplus power to drive an electric motor that compresses carbon dioxide at ambient temperature and pressure through a compressor 鈥?much like how a pump heats up when inflating a tire, compressing carbon dioxide also generates substantial heat. After storing this heat, the compressed carbon dioxide is condensed into liquid form for storage, which provides higher energy density and means more energy can be stored. During peak electricity demand periods, an evaporator gasifies the liquid carbon dioxide, then uses the heat stored during the energy storage process to heat the high-pressure liquid carbon dioxide into a high-temperature gaseous state, which then drives turbine blades to rotate and generate electricity.
The project is equipped with core equipment and control systems independently developed by Dongfang Electric, including carbon dioxide compressors, electric motors, turbine expanders, generators, pressure storage tanks, large heat exchangers, and high-power frequency converters. It adopts non-supplementary combustion gas-liquid phase change energy storage technology, featuring zero carbon emissions throughout the process, rapid response to grid dispatch, flexible startup and shutdown, wide load adjustment range, ground gas storage site selection unrestricted by geological conditions, and fully domestically produced and independently controllable core equipment. China's first 100-megawatt-scale compressed carbon dioxide energy storage project. Image courtesy of Dongfang Electric Corporation.
The project innovatively developed high-power-density axial and centrifugal compressor technology, paired with fully independently developed high-efficiency high-power carbon dioxide turbine technology. The turbine efficiency can reach over 90%, with an intake flow rate of 1,472.4 tons per hour, making it the compressed carbon dioxide power generation unit with the highest power generation efficiency in China, with power output and capacity both at industry-leading levels. The project is equipped with 600,000 kilowatts of wind power and 400,000 kilowatts of photovoltaic power, which will effectively smooth out wind and solar output fluctuations, reduce curtailment rates, and enhance the peak-shaving capacity and new energy consumption level of the Xinjiang regional power grid. After commissioning, the project can save approximately 50,000 tons of standard coal annually, reduce carbon dioxide emissions by approximately 170,000 tons, drive the development of local equipment manufacturing, engineering construction, and operation and maintenance service industries, continuously release green energy dividends, and support the green transformation of the local economy.