Global Warming’s Potential Impact on Wind Energy
Three things you need to know:
-- Increasing global average surface temperatures may reduce the amount of wind energy available for electricity production, a new study says.
-- Global air circulation is influenced by many aspects of the global climate, including differences in atmospheric temperatures between the equator and the North and South Poles.
-- Across North America, average wind speeds have decreased slightly over the past 40 years.
Turbines at Shanghai's Donghai Bridge Offshore Wind Farm capture wind energy in the late summer of 2010. A new study suggests that further global warming could reduce available wind energy by the end of this century. Credit: Alyson Kenward
People tend to think wind energy is a classic example of a renewable energy resource. But while it is true that wind will still blow no matter how many wind turbines are built, some new research suggests that wind power may decrease in some regions of the world as global temperatures rise.
Atmospheric scientist Diandong Ren, from the University of Texas at Austin, recently compared a number of common climate projections to study how wind patterns might change if recent global warming trends continue. Narrowing in on China, Ren found that each of the climate models indicated the wind power available over China, at the average height of a wind turbine, is expected to decrease by about 14 percent within this century.
“We show that the efficiency of tapping wind energy is adversely affected by future global warming,” says Ren, in his recent paper.
This research is among the first to clearly predict a continual decrease in wind energy as average global temperatures go up, but the reasons why wind energy potential might change is not yet entirely clear. Researchers already know that how air generally circulates on a large scale depends on the temperature differences between the equator and the more extreme Polar Regions. Furthermore, they expect that as global warming continues, the temperature difference between, say, the equator and the North Pole is expected to shrink, because the Arctic is warming much faster than the tropics.
It may be that these types of large scale changes in air circulation will contribute to the overall changes in wind speed and strength that Ren's study predicts, but it is still unclear what the more local affects will be and whether similar trends can be predicted for wind energy over the United States.
Ren's current findings are published in the Journal of Renewable and Sustainable Energy.
Why this science matters:
Ren’s study reveals that as average global temperatures increase, wind energy resources may decrease. On one hand, you might think this means there will be less of a reason to build wind turbines and develop our wind industry. But Ren says the opposite is true and that the results suggest wind infrastructure needs to be developed sooner rather than later.
“Harnessing wind quickly is imperative, simply because this energy resource will shrink as our climate warms,” he explains in his paper.
Indeed, the U.S. Department of Energy has already examined whether it will be possible to meet 20 percent of the country’s total energy demand by the year 2030 with wind energy. They found that this target is likely achievable, albeit with a significant investment into the country's wind power infrastructure. That analysis, however, did not take into consideration the effects that further temperature changes might have on the availability of wind.
Additionally, researchers in the United States have already observed that over the past 40 years wind speeds have decreased by a small, but significant, amount across the country, although this varies on a regional basis. On a year-to-year basis, this decline in wind energy hasn’t been consistent however, so researchers are not yet sure whether they can attribute the changes they’ve observed to the overall rise in average air temperatures since the 1950s, and further studies will be needed to confirm this global warming-wind energy connection.