On June 9, 2026, a bid for an energy storage project worth 4.4 billion yuan quietly emerged in the deep grasslands of Xilingol, Inner Mongolia.

The candidate for the EPC general contracting of the ground power station project of the compressed air energy storage project on the power grid side of Shenneng Xilingol West Ujimqin Banner has been officially announced. This is a non staged compressed air energy storage power station with a scale of 3 × 350MW/420MWh. After completion, it will become one of the largest and highest parameter artificial cavern type compressed air energy storage power stations in China and even the world.

Two power construction giants are facing each other head-on. In the end, Jiangsu Electric Power Construction First Company of China Energy Engineering Group won the first place with a price lower than the second place by 67 million yuan, surpassing Shanghai Electric Power Design Institute under China Electric Power Construction Group.

The small difference in a single quotation reflects a new stage of bidding for large-scale energy storage projects in China, shifting from technical competition to a dual competition of technology and cost.

Artificial chamber gas storage achieves the highest level in the world

The project is located in Bayanhua Town, Xiwuzhumuqin Banner, Xilingol League, Inner Mongolia Autonomous Region. It plans to construct a 3 × 350MW/420MWh non supplementary combustion compressed air energy storage power station and a 500kV booster station. The underground gas storage adopts an artificial chamber scheme, with a total volume of 639000 cubic meters and an operating pressure between 9.6 and 17 megapascals. The thermal storage system adopts a medium temperature technology route.

The designed service life of the ground power station is 30 years, with a rated charging time of 6.5 hours and a continuous power generation of up to 4 hours at full power. After completion, a 500kV transmission line will be connected to the Baolage 500kV substation. The project has a controlled price of 4.4 billion yuan and a construction period of 773 days, covering integrated tasks such as survey, design, procurement, construction, and commissioning.

67 million yuan price difference determines the winner

After fierce competition, the two units stood out from numerous bidders. China Energy Engineering Jiangsu Electric Power Construction Co., Ltd. ranked first among the candidates with a low price of 429336 million yuan, while Shanghai Electric Power Design Institute Co., Ltd. ranked second with a quotation of 436.046 million yuan. The difference between the two is about 67 million yuan, and the price advantage has become a key factor for China Energy Construction to break through.

China Energy Engineering Jiangsu Electric Power Construction Company has long been deeply involved in large-scale thermal power, new energy, and power grid projects, accumulating rich construction and technical experience in the field of energy storage. This low price winning bid is not simply a pricing strategy, but a comprehensive demonstration of strength based on engineering experience and cost control capabilities.

Zero carbon energy storage achieved through non supplementary combustion routes

The construction significance of this project goes far beyond the landing of an engineering contract. The wind and photovoltaic resources in the Ximeng region are abundant but highly volatile. The large capacity energy storage of 3 × 350MW/420MWh can achieve full power discharge for up to 4 hours, effectively smoothing out fluctuations in new energy output.

The artificial chamber gas storage technology has broken through geographical limitations and provided valuable experience for the construction of large-scale energy storage power stations in inland China in the future. Compared to supplementary combustion compressed air energy storage, non supplementary combustion routes consume no fossil fuels throughout the entire process, truly achieving zero carbon emissions and meeting the requirements of new power systems for green energy storage. Keywords: New energy news and information, energy storage

The project is also expected to become a landmark project for China's compressed air energy storage from demonstration to commercial operation, and provide a replicable project model for China's cooperation with countries along the the Belt and Road in the field of energy storage technology and equipment.Editor/Gao Xue