UHV transmission refers to AC transmission of 1,000 kV and above; and DC transmission of ±800 kV and above. The technology effectively transmits power by large capacities over long distances with little line losses. Since 2004, in collaboration with partners, State Grid has made breakthroughs in developing the UHV theory, technology, standards, equipment, as well as building and running UHV projects. The company has obtained proprietary intellectual property rights of the technology and promoted the export of technology and related equipment. This is a technology developed and led by China.
Up to date, State Grid has built and operated 14 AC and 12 DC UHV projects with two AC and three DC UHV projects under construction. The total 31 UHV projects cover 41,000 kilometers, with a transforming (converting) capacity of over 450 GVA (GW). Its UHV AC transmission technology won the Special Prize of the State Scientific and Technological Progress Award in 2012 and its UHV DC transmission technology was granted the same honor in 2017.
By 2020, over 2,100 TWh of power have been transmitted by the UHV lines, and State Grid has improved its capacity of resource allocation serving better power supply, reliable operation, clean energy development,and environmental protection.