Inner Mongolia Energy Group’s Dengkou Energy Storage Power Station Expands to 1.005 GW / 3.01 GWh, Becoming the World’s Largest Operating Energy Storage Facility
Date: 14 Dec 2025 |
Source: http://nm.people.com.cn, 14 December 2025
On 12 December 2025, Inner Mongolia Energy Group announced that its Dengkou County 400 MW / 1,600 MWh independent energy storage project has successfully connected to the grid and completed the first batch of charging and discharging tests. With this milestone, the MENGNENG Dengkou Energy Storage Power Station has expanded its total capacity to 1.005 GW / 3.01 GWh, making it the largest energy storage power station currently built and in operation worldwide.
The project is located in Dengkou County, Bayannur City, and adopts a hybrid technology route combining vanadium flow batteries (VFB) and lithium iron phosphate (LFP) batteries. The VFB system forms part of a regional “Jiebang Guashuai” (challenge-based) science and technology demonstration program, with reported performance including 80% energy efficiency at a single-cell rated current density of 500 mA/cm², and system energy efficiency above 72%, exceeding relevant industry standards.
Supported by the local government, the project progressed from formal construction start to grid connection and charge/discharge operation in just 80 days.
“Energy storage power stations have dual attributes as both load and power source,” said Ma Quanshan, project lead for the Dengkou Energy Storage Power Station at Mengneng New Energy Company. “They can provide peak shaving and valley filling, support stable grid operation, enable renewable energy integration, and improve utilization of wind and solar resources—making them a key link for coordinated development across the power system and industry.”
Inner Mongolia Energy Group’s New Energy Company has also developed 4.45 GW of installed photovoltaic capacity in Dengkou County. Following commissioning, the new storage capacity is expected to significantly enhance regional renewable consumption and power-system stability, support local sand-control and ecological restoration efforts, and create additional room for integrated wind-and-solar development. The project will also contribute a major demonstration reference for Inner Mongolia’s push toward a “source-grid-load-storage integrated” new-type power system.