Teams tackle complex terrain to construct ultrahigh voltage line

The Shaanxi section of the Gansu-Zhejiang ±800 kilovolt ultrahigh voltage direct-current transmission line project was completed in late September, accelerating the "Gansu power to Zhejiang" initiative and the direct delivery of northwest clean energy to the Yangtze River Delta.

As a backbone channel of the national "West-to-East Power Transmission" strategy, the Shaanxi section spans approximately 486 kilometers. It traverses four cities and 11 counties including Baoji, Hanzhong, Ankang and Shangluo, featuring terrain that ranges from 600 to 2,100 meters in altitude. The landscape is dominated by mountains and ravines. Of the terrain, general hills account for 27.4 percent, high mountains for 55.3 percent, and steep ridges for 17.3 percent.

Overcoming this complex geographical challenge, construction teams spent 15 months completing the foundation, tower assembly and wiring, realizing the full connectivity of the Shaanxi section.

During the construction of the Shaanxi section, the project involved crossing numerous power lines, including the ±800 kV Qinghai-Henan UHC DC power transmission line, the ±500 kV Deyang-Baoji power transmission line, four 750 kV lines, three 330 kV lines and 15 110 kV lines, as well as three expressways.

Facing a 70-day rainy autumn in southern Shaanxi in 2025, State Grid Shaanxi Electric Power Company pioneered the use of large-span mechanized bridges to cross the ±500 kV Deyang-Baoji power transmission line, providing a guarantee for the safe and efficient progress of the project.

Throughout the construction, State Grid Shaanxi Electric Power Company adhered to an eco-first approach to construction. They formulated specialized plans for soil and water conservation, ecological protection and vegetation restoration, establishing a whole-process supervision and control system.

In response to special construction scenarios, such as high mountains and forested ravines, they implemented green construction standards to control the scope of construction disturbance. By enforcing water and soil conservation measures, such as slope protection and re-greening, they achieved a synergy of power grid construction and ecological protection.

"The Shaanxi section project will now fully transition into the stages of handover acceptance, defect elimination, and system commissioning," said a manager at State Grid Shaanxi Electric Power Company.

"We will continue to strictly uphold standards for quality, safety and environmental protection to ensure the project is put into operation on schedule."