China\u2019s network of ultra-high-voltage (UHV) transmission lines is often described as a pillar of the country\u2019s clean-energy transition. With relatively low losses, it can move power thousands of kilometres, from renewable energy megabases in the country’s north and west, to demand hotspots along the populous eastern seaboard.<\/p>\n\n\n\n
But much of the electricity it carries still comes from coal. A system widely seen as essential for delivering clean power, now risks locking in fossil fuel.<\/p>\n\n\n\n
With China set to invest roughly RMB 5 trillion yuan<\/a> (over USD 700 billion) in its power grid by 2030, the next five years are a critical window to raise the renewable share on these UHV lines. The technology to do so exists \u2013 from storage to more flexible grid configurations \u2013 but the outcome will depend on whether policy frameworks in China shift to support its deployment.<\/p>\n\n\n\n No country has deployed UHV technology on a comparable scale to China. According to our research at Global Energy Monitor, by the end of 2025, the country had commissioned 45 UHV lines<\/a>, totalling 52,300 km and with a transmission capacity of about 300 gigawatts (GW). This accounts for over 70% of China\u2019s inter-regional and inter-provincial power-transmission capacity.<\/p>\n\n\n\n UHV transmission refers to alternating current (AC) lines operating at 1,000 kilovolts (kV) or higher and direct current (DC) lines at \u00b1800 kV or above.<\/p>\n\n\n\n UHVDC is typically used for long-distance, point-to-point transmission, while UHVAC is better suited for interconnected networks.<\/p>\n\n\n\n Compared with conventional grids, UHV lines that operate at far higher voltages allow proportionally lower current which can dramatically reduce energy loss along the way. This physical feature enables UHV lines to transmit far larger volumes of power over long distances, especially UHVDC, with higher efficiency and a smaller land footprint.<\/p>\n<\/div><\/div><\/div>\n\n\n\n The huge scale of UHV development reflects China\u2019s geography as much as its climate ambitions. Energy resources are concentrated in the north and west, while electricity demand is highest in the east and south. UHV has therefore become the backbone of China\u2019s long-standing \u201cwest-to-east power transmission<\/a>\u201d strategy.<\/p>\n\n\n\n But China\u2019s UHV system was not originally designed for wind and solar. Early projects were built mainly to transmit hydropower, with a small share of coal. Both of these sources offer stable, high-output electricity well suited for transferring large amounts of electricity over long distances.<\/p>\n\n\n\n A major shift came in 2014, when severe air pollution in northern cities prompted the government to plan 12 \u201cair pollution control transmission corridors<\/a>\u201d. The strategy sought to reduce coal-fired power generation in eastern regions by relying on electricity imports from the west.<\/p>\n\n\n\n Nine of these corridors were built as UHV projects and eight of those were designed to transmit coal-fired electricity. According to our Global Coal Plant Tracker<\/a>, between 2016 and 2019, they were commissioned alongside nearly 50 GW of new supportive coal capacity, more than a quarter of China\u2019s coal additions during that period.<\/p>\n\n\n\n The UHVs did help shift pollution away from cities in the east, but they also locked coal into long-distance power flows. Even today, wind and solar account for only around one-fifth<\/a> of electricity transmitted through UHV lines \u2013 a share that has barely increased since 2021, despite the rapid growth of renewables nationwide.<\/p>\n\n\n\nBuilt for distance, not decarbonisation<\/h2>\n\n\n\n