The state-owned State Grid Corporation of China has started construction of an ±800 kV ultra-high voltage flexible direct current (UHVDC) transmission project linking the provinces of Gansu (western China) and Zhejiang (eastern China). The project, touted as a world first, will enable the transmission of over 36 TWh/year of electricity to Zhejiang once completed, with more than half of this amount generated from renewable energy sources. The project, with a rated capacity of 8 GW and a total investment of about CNY35.3bn (US$4.82bn), will run for 2,370 km through six provincial administrative regions, namely the Gansu, Ningxia, Shaanxi, Henan, Anhui, and Zhejiang provinces.
Ultra-high voltage transmission lines refer to power transmission cables operating with greater than 800 kV of direct current, or 1,000 kV of alternating current. In January 2024, State Grid announced that it would invest CNY500bn (US$70bn) in grid network construction in 2024 to develop ultra-high voltage (UHV) lines, ensure power supply stability and boost renewable power consumption in China. State Grid expects to complete six UHV AC lines in 2024 and start several new UHV projects.