China’s State Grid Corporation has started building an ultra-high voltage (UHV) alternative current power transmission project in the Sichuan province and Chongqing municipality (southwestern China). The CNY29bn (US$4bn) project includes the construction of 658 km of 1,000 kV double-circuit lines. The project is expected to be commissioned in 2025, and some parts will be built at altitudes surpassing 4,000 m. Once the project is completed, the voltage of the main power grid in Southwest China is expected to increase from 500 kV to 1,000 kV, transmitting 35 TWh/year of power.
In July 2022, State Grid Corporation of China started operations for a major 2,080 km segment of the Baihetan-Jiangsu 800 kv UHV direct current transmission line, running from Sichuan to the Jiangsu province.