The rapid expansion of China's renewable energy is now running up against grid bottlenecks, keeping the country reliant on coal for electricity, according to a new report by Global Energy Monitor.
China leads the world in renewable capacity additions, with more than 500 gigawatts of wind and utility-scale solar capacity currently under construction.
For wind projects alone, China's development pipeline surged 37% over the past year, as the rest of the world saw a 1% decline, according to GEM.
Its prospective utility-scale solar and wind capacities stand at 664 GW and 698 GW, respectively, enabling it to meet its 2030 target by the end of this year, the report said.
However, the country's power grid has limited flexibility, resulting in solar curtailments rates between 10% and 17% and wind curtailment rates between 4% and 9% across the northern and northwestern regions, GEM highlighted.
At these curtailment rates, which pertain to wind and solar output that could have been consumed but was instead reduced or withheld, "wasted energy is rising," the organization said.
"Grid infrastructure is lagging and heavily reliant on coal," it also noted, referring to limited transmission capacity dedicated to renewable energy.
China's 15th five-year plan aims to add 10 ultra-high voltage direct current lines, while wind and solar mega-bases require 27 networks, according to the study.
While wind and solar power represent only around one-fifth of transmitted electricity across the UHVDC network, coal accounts for 42% and planned transmission "remains coal-linked," GEM said.
"Ultimately, the success of China's renewable energy mega-bases will not be measured by the gigawatts added, but by the volume of coal they actively displace," GEM research analyst Aiqun Yu said.