In the post-Katrina era, it’s the zillion-dollar question: How can we stop hurricanes from taking thousands of lives and causing billions of dollars in damages?
Massive offshore wind farms might be the solution, according to a new study published in the journal Nature Climate Change.
Using a computer model to simulate the devastating path of Hurricane Katrina, researchers at Stanford University and the University of Delaware found that an array of 78,000 wind turbines could be able to mitigate the hurricanes’ wind speeds, wave heights, and storm surges.
“We found that when wind turbines are present, they slow down the outer rotation winds of a hurricane,” said lead author Mark Jacobson, a civil and environmental engineering professor at Stanford University. “This feeds back to decrease wave height, which reduces movement of air towards the center of the hurricane, increasing the central pressure, which in turn slows the winds of the entire hurricane and dissipates it faster.”
Using a computer model he’s been developing for 20 years, Jacobson examined the relationship among air pollution, energy, weather, and climate. The simulations showed dramatic results: By the time Katrina made landfall, the offshore wind farm could have slowed the hurricane’s speeds from 140 miles per hour to 92.
Considering the reality of today’s offshore wind farms and the design limitations of the turbines themselves, the findings, though striking, are a bit far-fetched.
One of the largest offshore wind farms in the world, the London Array, in the United Kingdom’s Thames Estuary, has just 175 turbines. Jacobson’s simulation used 450 times this number. “It’s not practical—78,000 turbines,” Dominique Roddier, the co-inventor of a structure designed to support floating wind turbines, told USA Today. “That’s an insane number of wind turbines. You can’t build that many.”
Another debatable finding is Jacobson’s assertion that the offshore wind turbines could withstand a hurricane of Katrina-level proportions (its top wind speeds reached 140 miles per hour). Operators shut down current wind farms when gusts reach 125 miles per hour, according to Scientific American.
“We found that whether it’s the Gulf Coast or the East Coast, the hurricane actually dissipates by the time it reaches the turbines such that the wind speeds never get up to the destruction wind speed of the hurricane, even in something so powerful as Hurricane Katrina,” Jacobson said in a video. In the Katrina simulation, the turbines were located 62 miles off the Louisiana coastline.
Though the installation of such a large offshore array of turbines is considered politically unfeasible today, Jacobson says his research’s cost-benefit argument could change the current climate.
Monster hurricanes Katrina and Sandy caused $100 billion and $65 billion in damages, respectively. Yet Jacobson says that if the supersize wind farms had been in place when the hurricanes hit, the storms' costs would have been reduced. Flood damage and health care costs, for example, would have been reduced because of the wind turbines' ability to dissipate the hurricanes before hitting land.
Of course, that would assume that the turbines would be able to withstand the hurricanes’ top speeds in the first place.