Global warming could be causing long-term shifts in the generation of wind energy.
New research published yesterday in the journal Nature Geoscience suggests that future climate change might cause wind resources to decline across the Northern Hemisphere. These losses could be tempered by increases in wind power potential south of the equator, under severe climate change scenarios.
The findings don't disqualify wind as a competitive source of renewable energy, cautioned lead study author Kristopher Karnauskas of the University of Colorado, Boulder. But they do suggest that energy planners should take the future climate into account when creating long-term strategies for renewables.
"On a local level, I think this [study] can provide some important information in terms of planning and allocating resources, where to build new wind farms relative to other locations, or deferred maintenance—which ones to service next if you have finite financial resources," he told E&E. "And ultimately it's a recognition that the baseline wind energy resource can't be considered a constant."
It's already known that climate change can affect global wind patterns. One reason winds exist is because certain parts of the planet receive differing levels of solar radiation. The result is varying levels of atmospheric pressure around the globe, which affects the way air flows from one place to another.
So scientists are well-aware that changes in global temperatures—particularly when those changes are occurring faster in some regions, like the Arctic, than in others—may affect the flow of air around the planet. And these changes could have a big impact on the amount of power wind turbines are able to produce from the air flowing around them.
Some studies have previously investigated the issue on a small scale, using individual models or looking at specific regions of the Earth. But according to the authors, the new study is one of the first to examine the issue from a global scale, using an ensemble of different climate models.
The researchers investigated two potential future climate scenarios—a severe climate trajectory, in which average global temperatures could rise by more than 5 degrees Celsius by the end of the century, and a more moderate climate scenario, somewhat closer to what could be achieved by the global commitments made through the Paris climate agreement.
Under both scenarios, wind energy resources declined across the Northern Hemisphere. The changes varied by location—for example, in the central U.S., the study suggested wind power reductions of 8 to 10 percent by the year 2050. Other parts of the Northern Hemisphere could see declines as high as 40 percent by the end of the century.
On the other hand, some increases in wind energy resources were projected for the Southern Hemisphere, which could help to offset the decreases in the North—but only under the more severe climate change scenario.
"That irony was not lost on me when I saw the results that we were getting for the first time," Karnauskas said. "It looks like you get some sliver of good news on the higher-emissions scenario."
But he added that even under this trajectory, the increases in the Southern Hemisphere would be unlikely to totally counter the declines in the Northern Hemisphere.
"The Southern Hemisphere is not where most of the built-out wind farms are and not where most of the consumption is," he said.
According to Daniel Kammen, an expert on energy policy at the University of California, Berkeley, who was not involved with the research, the study reinforces similar findings described by other papers. The results, he said, embody "a disturbing but entirely expected consequence of climate change."
But it's not all bad news either.
The projected declines in the Northern Hemisphere are "not trivial," according to Karnauskas, but certainly not enough to deter decisionmakers from the continued expansion of wind energy. Rather, the study suggests that planners should pay more attention to future climate projections when deciding where to place wind farms and how to balance the portfolio of different renewables—including solar or hydroelectric power—in different regions around the world.
"Wind power should still be considered an important part of the portfolio of renewable investments, as part of the broader strategy to reduce carbon emissions and so forth," Karnauskas said. "And as renewables, including wind, are a part of the strategy, it's just important to make sure we fully understand how the potential efficacy of that strategy may be changing concurrently with the problem itself."
Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.