In the Chinese province of Jiangsu the largest energy storage system in the world to compressed air (CAES- Compressed Air Energy Storage), marking a historic milestone in the development of sustainable energy infrastructure. The power plant, with a total cost of approximately 520 million dollarsis sized to guarantee an annual production of approximately 792 GWh of electricity helping to meet the energy needs of 600 thousand domestic users per year. The project fits within the framework of the strategic objectives defined by the Beijing government, which envisage the achievement of more 180 GW of new energy storage capacity, against estimated investments of approximately 35 billion dollars.
A record-breaking energy infrastructure
The CAES plant in Huai’an represents one of the infrastructures more advanced for large-scale energy storage. The compressed air accumulation system is created inside cavities obtained from a former salt minelocated at depths between 1150 And 1500 metersand characterized by high impermeability and long-term geological stability. The power plant consists of two generation units 300MW each, for a total installed power of 600 MW, and is able to ensure an energy storage capacity equal to 2.4 GWh. The system has a conversion efficiency of 71%, placing itself between the higher levels performance achieved by CAES technologies on an industrial scale.
The plant acts as a gigantic one underground energy reserve. During hours of low demand or low energy costs, excess electricity is used to power compressors that pressurize approximately 980 thousand cubic meters of airstoring it inside the salt cavities. In the phases of maximum energy demand, the compressed air is released and conveyed into turbines for the generation of electricity. This mechanism allows you to increase the resilience of the electrical system through the compensation of peak loads (peak-shaving) and the adjustment of the network frequency.
What technology does it adopt and how does the system work?
A distinctive feature of the plant is the adoption of a technology high adiabatic temperature which allows the heat generated (up to 600°C) during the compression phase to be recovered and stored through a thermal storage system molten salts and pressurized thermal water. The heat thus stored is subsequently released to heat the air flow entering the turbine, improving the overall efficiency of the thermodynamic cycle. Unlike conventional CAES systems, this operational configuration allows for eliminate the use of combustion of fossil fuelallowing thezeroing of direct carbon dioxide emissions (CO2) and a significant reduction in environmental impact. According to estimates, under nominal operating conditions, the power plant will avoid the consumption of approximately 250 thousand tonnes of coal and reduce emissions by 600 thousand tons of CO2 per year.
Future prospects of CAES
With the start of commercial activities, the Huai’an plant consolidates its position Chinese leadership in the energy storage sector and represents a technological model potentially replicable on a global scale. However, the adoption of similar solutions results conditioning by the availability of specifications geological featureswhat about limit applicability to suitable territorial contexts. The relevance of this initiative is closely connected to the growing need for efficient and sustainable energy storage systems. The increase in production from non-programmable renewable sources, such as wind and solar, makes it necessary to implement alternatives capable of store excess energy and release it at times of greatest demand, ensuring continuity and reliability of the electricity supply.
