China's State Grid to Pivot to VSC Technology
UHVDC technology - generally categorized as HVDC projects with a DC voltage above 600 kV - allows bulk electricity to be transmitted over very long distances with minimal losses, making it useful for transmitting power that is generated a long distance from theload centres.
These systems are particularly prevalent in China (see World Map), where UHVDC is used to transmit large amounts of power over very long distances. For example, from the Three Gorges dam to load centres in Shanghai and Guangdong. As a result, China has established itself as the global leader in UHV technology, with over 50,000 kilometers of UHV transmission lines in operation by 2025. The country has invested the equivalent of approximately 200 billion euros in UHV infrastructure, with an additional 50 billion euros in construction in 2024.
China's existing UHVDC expertise has achieved several world records. For example, China's flagship project, the Changji-Guquan link, operates at 1100kV and can transmit up to 12GW of electricity - the equivalent of Sweden's total average power demand.
Following on from this, the next milestone in UHVDC is close to being realized - the first Voltage Source Converter (VSC) ±800kV 8GW HVDC project in the world; the Gansu-Zhejiang Project, will be commissioned in 2026 to support large-scale clean power integration in China. Ultimately, China sees the benefits VSC schemes provide in overcoming weak remote networks dominated by renewable energy sources, and intends to proliferate this technology into future transmission projects.
On January 8, the State Grid Corporation of China held the "±800kV/8GW" UHV VSC DC technology achievement release and application promotion" meeting. At the meeting it was announced that "the development of ±800kV 8GW UHV flexible DC is an urgent need to serve the large-scale development of new energy and help achieve the goal of "double carbon", to strengthen the safety and stability of large power grids and build a new power system, and to promote the development of the industrial chain and cultivate new technology."
This advancement comes at an important time as countries worldwide seek efficient solutions for integrating renewable energy sources into their power grids. UHV technology is particularly valuable for nations with geographically dispersed renewable resources and population centers, such as China.
