Researchers at Simon Fraser University have tracked declining wind speeds over land in the Pacific Northwest, which appears linked to climate change and has implications for the nascent wind energy field.
By contrast, the study of existing wind data stretching back to the 1950s found that coastal winds were stronger and showed eight-to-nine-year waves in the overall trend.
“One [implication] is that this is something that needs to be taken into account for wind power,” Karen Kohfeld, an assistant professor in SFU’s department of resource and environmental management. “It needs to be estimated into their calculations of what the payback time [for a project] is.”
According to the Global Wind Energy Council, Canada in 2009 generated just one per cent of its electricity needs with wind.
The goal of the Canadian Wind Energy Association, however, is to boost that to 20 per cent by 2025.
The research, conducted by Brad Griffin, one of Kohfeld’s students, found a trend showing winds in overland areas have slowed by three to five per cent per decade since the 1950s.
Over coastal areas, winds are stronger, and Kohfeld said neither trend can be explained by regular climate swings such as El Nino.
The study looked at wind data from 92 stations stretching from Lytton and Hope in inland B.C., west to Vancouver Island and south into western Oregon.
Kohfeld said urbanization may have played a role in stilling inland winds, but bigger factors, such as a northerly shift in the global atmospheric circulation system that controls major wind patterns known as the Hadley Cell.
That shift has been predicted by climate-change forecasters.
“That could bring lower pressure differences or extensive high-pressure zones and lower wind speeds to mid-latitudes around the world,” said Kohfeld, who holds a Canada Research Chair in climate resources and global change at SFU.
Kohfeld added that the results of Griffin’s research are similar to studies that show declining wind speeds in parts of Europe, the United States, Australia and parts of Asia.
Understanding winds are crucial to wind-energy projects, although for proponents of wind projects, data that is as localized as possible is more important than trends.
“The longer you have localized data sets that [are] third-party verified, have looked at your wind and potential output, those are core to financing a project,” said T.J. Schur, director of external relations at Victoria-based Aeolis Wind Power Corp.
That information is the basis for determining a project’s electricity output and financiers want to have confidence that output (and the project’s revenue) will be consistent over time.
“It’s a fundamental component to turning a potential project into a real project.”
Aeolis is a developer of wind-power that has identified potential wind-farm sites in B.C.’s northeast and on Vancouver Island.
Schur said she couldn’t speak to the SFU study but added that a trend study is only one tool “wind prospectors” will use in their work finding potential sites.
For most of B.C., Schur said, the difference in topography location to location has a huge influence over wind speeds often more so than the trends.
And in northeast B.C., Schur said the long-term-trend data Aeolis has examined has shown the wind speeding up in that region.
However, Schur added that if the coastal wind-speed trend is a result of climate change, she believes it helps make the case for pursuing renewable wind energy more aggressively.
“We’re trying to slow climate change by being in the renewable energy sector,” Schur said.
Kohfeld said the extremes of wind speeds in coastal areas might make those areas look like they have more potential for wind energy, but her team wants to understand the cycles better.
Kohfeld added that the next step for the team, which includes Griffin and SFU associate professor Andy Cooper, is to see if they can forecast some of the wind changes using models.
“Brad has started to try to do that, and one of the things he’s found out is that where you are located is a lot more important than what the climate cycles are in our study,” she said.
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