Massive offshore turbine arrays would help us harness hurricanes

What would happen if a hurricane were to plough through a wind farm consisting of tens of thousands of individual turbines? A Stanford engineer recently ran a computer simulation to find out — and the results were astonishing.

Given the often devastating impacts of climate change, the need for effective weather control systems has never been more urgent. It may be a while — if ever — before we partake in geoengineering projects that mitigate the effects of rising carbon dioxide levels, so it may be incumbent upon us to develop such schemes. We've already engaged in cloud-seeding to facilitate rain and snow (a technique that would really help drought-stricken regions like California). And looking ahead the future, we could eventually build a weather machine to create a programmable atmosphere.

But as a recent study by Stanford engineer Mark Z. Jacobson shows, we may already have the means to mitigate one of the most powerful forces of nature known to humanity.

How to Tame a Hurricane

With the help of Cristina Archer and Willett Kempton of the University of Delaware, Jacobson set about the task of figuring out what would happen to wind farms when faced by the onslaught of a hurricane. The team was curious to know if the turbines would get wrecked, or if they might be capable of literally sucking the energy out of the storm.

To find out, they developed a computer model that simulated the effects of several hurricanes as they encountered massive arrays of offshore wind farms. And by massive, we're talking about wind farms that stretch for many miles along susceptible coasts and consisting of as many as 78,000 individual turbines. The virtual wind farms were confronted with three simulated hurricanes: Sandy and Isaac, which struck New York and New Orleans, respectively, in 2012, and Katrina, which devastated New Orleans in 2005.

Incredibly, the simulations showed that wind turbines could disrupt a hurricane enough to reduce peak wind speeds by up to 92 mph (148 km/h) and decrease storm surges by up to 79%.

"We found that when wind turbines are present, they slow down the outer rotation winds of a hurricane," noted Jacobson in a statement. "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."

According to the simulations, a wind farm placed off the coast of New Orleans could have reduced Hurricane Katrina's wind speed by 36-44 meters per second (between 80-98 mph) while decreasing the storm surge by up to 79%. In the case of Hurricane Sandy, the wind farms would have reduced wind speed by 35-39 meters per second (between 78-87 mph) and the storm surge by as much as 34%.

Massive offshore turbine arrays would help us harness hurricanes

Image: The London Array as seen from space. NASA Earth Observatory.

Quite obviously, these arrays wouldn't stop the hurricane altogether, but they could significantly diminish their destructive power once they make landfall.

As for the integrity of the wind farms themselves, current turbines can withstand wind speeds up to 112 mph (180 km/h) — the range of category 2 to 3 hurricanes. But Jacobson says that the presence of massive turbine arrays would likely prevent hurricane winds from reaching those speeds.

A Solution That Pays For Itself

Regrettably, there's political resistance in the United States to installing a few hundred offshore wind turbines, let alone tens of thousands. But as Jacobson argues, wind turbines would pay for themselves in the long term by generating normal electricity, while reducing air pollution and global warming.

Moreover, because the turbines would prevent more wide scale damage, they would also reduce the hard costs of cleaning up after a hurricane. For example, Hurricane Sandy cost roughly $82 billion in damage across three states.

Read the entire study at Nature Climate Change: "Taming hurricanes with arrays of offshore wind turbines."

Image: Horns Rev offshore windfarm west of Denmark.
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