February 26, 2014
Wind Turbines Could Tame Hurricanes
Brett Smith for redOrbit.com - Your Universe Online
According to a new study in the journal Nature Climate Change, thousands of offshore wind turbines could diminish hurricanes' wind speeds, wave heights and storm surge.
"We found that when wind turbines are present, they slow down the outer rotation winds of a hurricane," said study author Mark Z. Jacobsen, a professor of civil and environmental engineering at Stanford University. "This feeds back to decrease wave height, which reduces movement of air toward the center of the hurricane, increasing the central pressure, which in turn slows the winds of the entire hurricane and dissipates it faster."
In determining the global capability for wind power for a previous study, Jacobsen noted that as turbines are generating usable energy, they are also drawing energy from the atmosphere. He discovered that there is more than enough wind to service global energy demands with a minimal effect on the global climate.
In the new study, the scientists looked at how the turbines' wind removal might have an impact on hurricanes. In contrast to normal long-term weather patterns, massive storms act in a strange manner. The authors hypothesized that a hurricane might be more impacted by wind turbines than typical winds.
"Hurricanes are a different animal," said study author Cristina Archer, a climatologist at the University of Delaware.
The study team developed a model that simulated a hurricane encountering an immense wind farm extending several miles offshore and along the coast. The team learned that the wind turbines could affect a hurricane enough to cut back peak wind speeds by up to 92 mph and reduce storm surge by up to 79 percent.
The researchers used their model to simulate hurricanes Katrina, Isaac and Sandy and see what would happen if large wind farms had been in the storms' paths. They watched as lower wind speeds at the hurricane's edge would gradually shift inwards toward the eye of the storm.
"We found that when wind turbines are present, they slow down the outer rotation winds of a hurricane," Jacobson said. "This feeds back to decrease wave height, which reduces movement of air toward the center of the hurricane, increasing the central pressure, which in turn slows the winds of the entire hurricane and dissipates it faster."
Citing political resistance to installing wind turbines off the coast of the US, Jacobsen noted that there are two financial rewards that could encourage installation. One is the reduction of financial damage. Caused by substantial winds and flooding, hurricane damage can run into the billions. Hurricane Sandy, for instance, induced roughly $82 billion in damage across three states.
Second, Jacobson said the wind turbines would pay for them themselves in the long term by generating electricity while minimizing air pollution and global warming.
"The turbines will also reduce damage if a hurricane comes through," Jacobson said. "These factors, each on their own, reduce the cost to society of offshore turbines and should be sufficient to motivate their development.”