Ultra-high-voltage electricity transmission in China

On the transmission and distribution side, the country has focused on expanding capacity and reducing losses by:

1. deploying long-distance ultra-high-voltage direct current (UHVDC) and ultra-high-voltage alternating current (UHVAC) transmission
2. installing high-efficiency amorphous metal transformers^[5][6]

Ultra-high-voltage overhead power lines circuits have long been in use in many parts of the world. For example, 2,362 km of 1,150 kV circuits were built in the former USSR, and 427 km of 1,000 kV AC circuits have been developed in Japan (Kita-Iwaki powerline). Experimental lines of various scales are also found in many countries.^[7] However, most of these lines are currently operating at a lower voltage due to insufficient power demand or other reasons.^[8][9]

In 2015, the State Grid Corporation of China proposed the Global Energy Interconnection, a long-term proposal to develop globally integrated smart grids and ultra high voltage transmission networks to connect over 80 countries.^[10] The idea is supported by CCP general secretary Xi Jinping and his leadership in his attempt to develop support in various internal forums, including UN bodies.^[11]

China's focus on UHV transmission is partly driven by the geographic separation between major energy resources and demand centres.^[12] A significant share of China's solar power capacity is located in the solar-rich, sparsely populated western and northern regions, while studies have found that more than 99% of the country's technical potential for concentrated solar power is located in the western provinces of Xinjiang, Inner Mongolia, Qinghai, Gansu, and Tibet.^[13][14] The majority of the hydropower resources are in the west, while coal resources are concentrated in the northwest. Major electricity demands, however, is concentrated in the east and south, including major cities such as Beijing and Shanghai.^[5][7] To reduce transmission losses over these long distances, UHV transmission is a logical choice. At the 2009 International Conference on UHV Power Transmission in Beijing, the State Grid Corporation of China announced plans to invest RMB 600 billion (approximately US$88 billion) in UHV development by 2020.^[15]

Implementation of the UHV grid enables the construction of newer, cleaner, more efficient power generation plants far from population centers. Older power plants along the coast will be retired.^[16] This will lower the total current amount of pollution, as well as the pollution felt by citizens within urban dwellings. The use of large central power plants providing electric heating are also less polluting than individual boilers used for winter heating in many northern households.^[17] The UHV grid will aid China's plan of electrification and decarbonization,^{[citation needed]} and enable integration of renewable energy by removing the transmission bottleneck that is currently limiting expansions in wind and solar generation capacity whilst further developing the market for long-range electric vehicles in China.^{[citation needed]}

As of 2023, the operational UHV circuits are:

The under-construction/In preparation UHV lines are:

• Southern Hami–Zhengzhou UHVDC
• Electricity sector in China