BLOG/TECHNICA

According to State Grid Corporation’s plan, during the 14th Five-Year Plan period, the total investment in UHV AC and DC projects will reach RMB 300.2 billion, with 12,600 kilometers of new UHV AC transmission lines and 174 million kVA of additional substation capacity, as well as 17,200 kilometers of new DC transmission lines and 163 million kW of additional converter capacity. As a result, the UHV grid is set to enter a new phase of intensive construction.

Recently, the Baihetan–Zhejiang ±800 kV ultra-high-voltage direct-current transmission project received approval from the National Development and Reform Commission, marking the 10th UHV line to be approved since the resumption of UHV projects in 2018.

According to the “Notice on Accelerating the Planning and Construction of a Batch of Key Transmission and Transformation Projects” issued by the National Energy Administration in 2018, it was planned at the time to approve 12 UHV transmission lines by the end of 2019.

According to industry insiders, although the pace of UHV project approvals since the resumption has fallen short of expectations, under the broader context of building a new-type power system and achieving carbon peaking and carbon neutrality, the 14th Five-Year Plan period is set to see a surge in the commencement of UHV construction projects.

01

Multiple projects are awaiting approval.

A review of ultra-high-voltage (UHV) project commencement over the past five years reveals that China recorded zero UHV projects initiated in both 2017 and 2020. Even in 2018, when the state resumed UHV projects, only six UHV transmission lines were commissioned. At present, the Zhumadian–Wuhan UHV AC project and the Nanchang–Wuhan UHV AC project remain pending approval.

Following the commissioning last year of the Mengxi–Jinzhong 1,000-kV and Zhangbei–Xiong’an 1,000-kV UHV transmission lines, this year has seen the addition of three more UHV projects: the Qinghai–Henan ±800-kV line, the Northern Shaanxi–Wuhan ±800-kV line, and the Ya’an–Jiangxi ±800-kV line. Industry insiders believe that, thanks to its technical advantages—such as large transmission capacity, long-distance capability, and high efficiency—UHV technology can significantly boost grid transmission capacity, facilitate the integration of renewable energy in Northwest and Southwest China, and reduce curtailment rates for hydropower, wind power, and solar power. As a result, UHV infrastructure development is poised to enter a period of robust growth. According to sources familiar with the matter, State Grid Corporation of China will accelerate the construction of UHV projects within its operating area over the next five years, with numerous UHV initiatives planned during the 14th Five-Year Plan period. It is estimated that the number of UHV projects commencing construction in China during this timeframe could reach as many as 13.

Sources familiar with the matter told reporters that, according to State Grid Corporation’s plans, during the 14th Five-Year Plan period, total investment in UHV AC and DC projects will reach RMB 300.2 billion. This includes adding 12,600 kilometers of UHV AC transmission lines with a substation capacity of 174 million kVA, as well as 17,200 kilometers of UHV DC lines with a converter capacity of 163 million kW, ushering in a new phase of intensive construction for the UHV grid. “At present, the UHV projects awaiting approval include the ±800 kV Jinshang–Hubei DC line, the Longdong–Shandong DC line, the Hami North–Chongqing DC line, and the 1,000 kV Sichuan–Chongqing UHV AC line.”

According to interviews with reporters, all ongoing ultra-high-voltage projects are being vigorously advanced, and the ±1,000 kV Nanchang–Changsha UHV AC transmission project, scheduled for completion and commissioning by the end of 2021, is progressing on track. “At the construction site of the new 1,000-kV substation in Nanchang, Jiangxi, nearly 900 grid‑construction workers are making full use of this autumn’s favorable weather to carry out intensive work. To date, more than half of the equipment installation has been completed, and we plan to finish the entire 1,000-kV GIS installation by the end of this month,” said Wei Chunhua, the on-site project manager of Jiangxi Provincial Transmission and Transformation Engineering Co., Ltd.

02

Optimizing Regional Energy Supply and Demand

According to industry experts, China’s resource endowments and load centers are distributed in opposite geographic patterns. Ultra-high-voltage transmission, serving as a linking platform, effectively addresses this mismatch and enables large-scale, cross-regional energy allocation.

Data show that during the 13th Five-Year Plan period, ultra-high-voltage (UHV) inter-regional and inter-provincial power transmission volumes exhibited a steady upward trend. Last year, State Grid’s UHV inter-regional and inter-provincial transmission reached 2,076.413 billion kWh, and this year it is projected to climb to 2,441.541 billion kWh. By 2025, the State Grid’s operating area aims to achieve an inter-provincial and inter-regional transmission capacity of 300 million kW, with clean energy accounting for 50% of total transmitted power.

This summer, Zhejiang’s peak electricity demand across the entire society exceeded 100 million kilowatts for the first time, while both the Lingzhou–Shaoxing UHV DC transmission project in Ningxia and the Xiluodu–Jinhua UHV DC project in Sichuan operated at full capacity. Particularly during the peak‑demand period of the summer, supply‑demand balance at both sending and receiving ends nationwide remained tight, underscoring Zhejiang Province’s urgent need to enhance its capacity to integrate clean energy. Industry experts believe that the approval of the Baihetan–Zhejiang ±800 kV UHV DC transmission project could not have come at a more opportune moment; once commissioned, it will significantly bolster interprovincial power‑support capabilities.

Several respondents noted that, in addition to enabling large-scale interprovincial energy transmission, the UHV industry has played an exceptionally prominent role in driving economic growth.

According to data from CCID Consulting, in 2020, the total investment spurred by China’s UHV industry and its upstream and downstream supporting sectors exceeded RMB 300 billion, with nearly RMB 100 billion invested directly in the UHV sector and over RMB 200 billion in related social investment. By 2022, the total investment driven by China’s UHV industry and its supply chain is projected to reach RMB 414 billion; by 2025, the combined investment in the UHV industry and its ancillary sectors is expected to climb to RMB 587 billion. Supported by expectations for UHV infrastructure development under the 14th Five-Year Plan, capital markets have been particularly buoyant lately, with the UHV sector posting strong gains.

03

The approach to UHV construction has shifted.

According to industry experts, UHV infrastructure development is shifting from the traditional model—where generation, transmission, distribution, and consumption are integrated and operated in a unified manner—to a more coordinated, interactive approach that balances supply, grid, load, and storage on a non‑fully real‑time basis. To effectively support the development and utilization of diverse renewable energy sources and their high‑penetration integration into the grid, and to enable seamless access for various types of energy facilities, it is imperative to accelerate the construction of the UHV grid and promptly establish a robust, smart grid with UHV lines serving as its backbone.

“The approach to UHV development has shifted compared with the past, aligning with China’s current industrial transformation and upgrading,” the informed source stated plainly.

According to reports from reporters, in order to ensure high-quality construction of UHV projects during the 14th Five-Year Plan period, State Grid Ultra-High Voltage AC Company and State Grid Ultra-High Voltage DC Company have been merged into the UHV Construction Branch of State Grid Corporation of China.

An industry insider who asked not to be named told reporters that ensuring a reliable power supply in the eastern and central regions during the 14th Five-Year Plan period is an urgent challenge. While electricity demand growth is expected to moderate compared with previous periods, the pressure to maintain grid balance will intensify as China works to build a new‑type power system. Accordingly, accelerating the construction of a 1,000‑kV interprovincial transmission network in Central China to meet cross‑provincial power exchange needs has become one of the most pressing priorities.