Last month Energywise argued that the primary reason Chinese wind farms underperform versus their U.S.-based counterparts is that China’s grid operators deliberately favor operation of coal-fired power plants. Such curtailment of wind power has both economic and technical roots, and it has raised serious questions about whether China can rely on an expanding role for wind energy. New research published today appears to put those concerns to rest, arguing that wind power in China should still grow dramatically.
The report today in the journal Nature Energy projects that wind energy could affordably meet over one-quarter of China's projected 2030 electricity demand—up from just 3.3 percent of demand last year.
In fact the researchers, from MIT and Tsinghua University, project that modest improvements to the flexibility of China’s grid would enable wind power to grow a further 17 percent. That, they argue, means that China's non-fossil resources could grow well beyond the 20 percent level that China pledged to achieve under the Paris Climate Agreement.
These projections come at an important moment. Curtailment of wind farms nearly doubled last year from 8 percent to 15 percent of total wind output, according to InsideClimate News. Curtailment jumped the most in northern provinces that boast some of China’s best wind resources. Wind farms in Gansu province, the hardest hit, lost 39 percent of their generation.
In response, Chinese officials ordered a moratorium on wind farm approvals in Gansu and five other northern regions. They also have begun to question wind power’s future potential, according to Jiahai Yuan, an environmental economist at Beijing's North China Electric Power University. Growing curtailment has "raised calls for a radical rethinking on wind policy,” writes Yuan in an accompanying essay in Nature Energy.
Today's MIT-Tsinghua report relies on an hourly dispatch model for China’s grids that Yuan calls a "first of its kind." The model determines the optimal hourly output of various classes of generators to meet electricity demand at least cost, subject to various operational constraints. The latter include the availability of flexible power plants to back-up variable wind power, must-run generation such as coal-fired plants that provide steam to cities in winter, and transmission bottlenecks.
As a base case the MIT-Tsinghua team finds that 2,590 terawatt-hours of wind energy could be accommodated in 2030 at roughly the current cost of wind energy. The projected generation would be 26 percent of anticipated demand in 2030.
Cheap wind generation projected for 2030 rises to over 3,000 TWh with improved grid flexibility. Flexibility measures include enabling coal generators to ramp down to 40 percent of rated capacity when winds are strong (rather than the current 50 percent limit) and scheduling power plant operation daily instead of weekly or monthly.
Interestingly, the MIT-Tsinghua model also affirms Chinese energy officials’ reticence to rely on additional wind power in the windy north. Their 2030 projection instead tilts wind farm installations toward central and eastern provinces, which need more power and have fewer must-run coal plants.
As the authors put it, geographic detail is an important output from the model that could help energy planners worldwide:
“Failing to consider the grid-integration step … when developing national blueprints for the spatial distribution of future electricity capacity can yield vastly different recommendations for planning. Integration cost should not be overlooked.”
Peter Fairley has been tracking energy technologies and their environmental implications globally for over two decades, charting engineering and policy innovations that could slash dependence on fossil fuels and the political forces fighting them. He has been a Contributing Editor with IEEE Spectrum since 2003.