China's world-leading renewable megabases rely on coal-heavy transmission, report finds

By Colleen Howe

BEIJING, July 21 (Reuters) - China is building more large-scale wind and solar than the rest of the world combined, but inadequate transmission links and a continued reliance on coal-fired power are limiting its use, according to a report published on Tuesday.

• Wind and solar make up around 20% of the power sent through China's ultra-high voltage direct current (UHVDC) transmission network, little changed since 2021, while 42% is from coal, the Global Energy Monitor said.

• Under China's energy megabases policy, green power is generated in the sparsely populated north and northwest and sent via ultra-high voltage direct current (UHVDC) transmission lines to power cities and factories in the east.

• Some 315GW of megabase capacity will need outbound transmission by 2030, requiring 27 UHVDC lines, the report said. China aims to have 10 under its five-year plan for 2026-2030.

• The current 11 proposed transmission lines dedicated to megabases combine 129 gigawatts (GW) of wind and solar with 40 GW of coal, and the projected electricity mix is split almost evenly between coal and renewables, the report said.

• The high proportion of coal is hard to square with policymakers' framing of coal as having only a supporting role in China's power system, said report author Aiqun Yu, senior East Asia strategist for GEM.

• Yu said renewables bases should use energy storage technologies to back up intermittent renewables, instead of coal.

• For example, a proposed UHVDC line from Inner Mongolia's Kubuqi to Shanghai has renewables making up more than 60% of the planned transmission volume, backed up by 9,000 megawatt hours (MWh) of energy storage and 2.64 GW of coal where other similar projects have 4GW. "This is a small step forward," Yu said.

• As of June 2026, China had 664 GW of solar planned or under construction, making up one-third of the global total, the report found. China has 698 GW of proposed wind capacity, or one-quarter of the global total.

(Reporting by Colleen Howe; Editing by Kate Mayberry)