The world's first 300-megawatt (MW) compressed air energy storage (CAES) station in Yingcheng, central China's Hubei Province was connected to the grid for power generation for the first time on April 9.

This groundbreaking project has set world records in single-machine capacity, energy storage scale, and conversion efficiency, and achieved ten international firsts and global breakthroughs in six industries.

The Yingcheng project in Hubei is the first grid-connected 300MW CAES project in the world. As a national new-type energy storage pilot and demonstration project, it adopts CAES solutions independently developed by Energy China. It was listed in China's third batch of newly-developed major technological equipment in the energy sector.

The project's core CAES equipment, including the expander and compressor, was recognized as one of the top 10 technological innovation achievements in the energy industry in 2023.

With a total investment of 1.95 billion yuan ($269.46 million), the project's single-machine capacity reaches 300MW. When the energy storage scale stands at 1,500MW, the conversion efficiency of the project's system will hit about 70 percent.

As a typical representative of new-type energy storage technologies, CAES is currently one of the most mature physical energy storage technologies besides pumped-storage hydropower. It is also a hotspot in the research and development of large-scale, long-duration energy storage technologies today.

The station, dubbed a "super power bank", was built in about two years, much shorter than six to eight years required for a pumped-storage hydropower plant. In terms of scale, lifespan, cost, and efficiency, the station and a pumped-storage hydropower plant are evenly matched.

CAES is a key technology for building China's new energy system and new power system, as well as an important direction for cultivating strategic emerging industries.

This project utilizes abandoned salt mines in Yingcheng as air storage caverns. During the construction of the project, Energy China and other developers ensured that all the project's key core technical devices were manufactured domestically and overcame challenges in the integration of process systems, the development of critical equipment for the construction of underground air storage caverns, and other aspects. This has enabled proprietary intellectual property rights and standard systems in this field, forging a series of cutting-edge technologies and supporting products, which are the first of their kind in the world.

Upon completion, the Yingcheng project can effectively improve peak-shaving capacities of the regional power grid and enhance the grid's ability to absorb more electricity generated from renewable energy sources including wind energy and solar energy.

The project can store energy for eight hours and discharge energy for five hours per day, with an annual gas storage capacity of 1.9 billion cubic meters with the generation of 500 million kWh of electricity. It will provide an important driving force for industrial upgrading and economic development in central China.

The project, which was jointly invested by China Energy Digital Technology Group Co., Ltd. and State Grid Hubei Integrated Energy Services Co., Ltd., with Central Southern China Electric Power Design Institute Co., Ltd. of China Power Engineering Consulting Group as the EPC contractor, has injected new momentum into the development of new quality productive forces. 

Constructed by China Energy Engineering Group Hunan Power Construction Co.Ltd. and China Energy Engineering Group Southern Construction & Investment Co., Ltd., the project has been operated and maintained by China Energy Digital Technology Group Co., Ltd.

Beijing North-Star Technology Development Co.,Ltd., has offered whole-process digital and smart services while China Energy Engineering Group Equipment Co., Ltd has provided primary and secondary core equipment, along with equipment monitoring and management services for the main components.

At present, Energy China has over 50 CAES projects that meet the implementation conditions and are under construction across the country, including in cities like Jiuquan, Chaoyang and Tai'an.

The company has also initiated the research and development of key core technologies for 600MW to 1,000MW CAES projects with conversion efficiency ranging from 72 percent to 75 percent.