The Guo'ao double-circuit cross-border transmission line. [Photo/Inner Mongolia Daily]

China and Mongolia achieved direct power grid interconnection for the first time on Sept 16, marking a milestone in energy cooperation between the two countries.

The interconnection was completed at 12:32 am when Mongolia's 220-kilovolt Tavan Tolgoi Substation was connected to the power grid in North China's Inner Mongolia autonomous region.

The project enables electricity from Inner Mongolia to be transmitted to Mongolia's South Gobi Province through the 220-kV Guo'ao double-circuit cross-border transmission line, which starts in Urad Middle Banner, Bayannuur.

Chinese and Mongolian teams hold a technical coordination meeting during the project's preparatory phase. [Photo/Inner Mongolia Daily]

The project is a landmark initiative in China-Mongolia energy cooperation. After Mongolia proposed cooperation in February 2023 to strengthen the power supply to its southern region, the two sides quickly established a cross-border coordination mechanism and worked through multiple stages of construction and commissioning.

Initial power transmission began in July 2026, two substations were energized in early September, and full grid interconnection was completed on Sept 16.

The project will provide a more stable electricity supply for industrial and mining projects and local communities in southern Mongolia. Under a cross-border green power cooperation mechanism, green electricity is expected to account for more than 40 percent of Inner Mongolia's electricity exports to Mongolia.