By PETER S. GREEN
Sept. 28, 2014 4:56 p.m. ET
Could an armada of giant windmills reduce damage from the next big hurricane?
A study by scientists at Stanford University and the University of Delaware suggests that U.S. coastal cities could be spared by installing tens of thousands of gigantic wind turbines offshore in arrays up to 20 miles long. The scientists say the turbines, as high as a football field is long, would suck much of the energy out of storms and pay for themselves with the clean electrical power they produce.
The idea is that if you take away enough wind speed and reduce the height of the waves, you will break the feedback loop that makes hurricanes more powerful. Computer models in the study show that the giant turbines—with blades more than 400 feet across, and hubs nearly 330 feet above the water—would cut the wind’s force by about half.
During Hurricane Katrina in 2005, to cite an example from the study, having 78,000 turbines off the coast of New Orleans would have reduced the storm surge that swamped the city by as much as 71% and cut wind speeds by as much as 57%.
Still, while the physics may be sound, the economics may be less so: The study’s authors propose 121,000 7.5-megawatt turbines or 181,000 five-megawatt turbines along the U.S. coastline, for total costs of $2.7 trillion, or about $77 billion a year over 35 years. As an extra incentive, the turbines not only would offer hurricane protection but would produce 20% of all U.S. power by 2050.
But there are now only about 1,900 offshore turbines in the top 25 offshore wind farms in the world, and none in the U.S.
At CIT Group Inc., a New York City-based provider of commercial lending and leasing services, Mike Lorusso, managing director of the company’s energy group, says it would be impossible to secure financing for a project of such immensity. Siting and erecting 120,000 towers near coasts and shipping lanes, he says, would be an insurmountable hurdle.
Mark Z. Jacobson, a co-author of the wind-turbine study, is aware that the idea faces, well, headwinds. But he argues it is the best option available.
“The alternative is sea walls, which could cost $30 billion for one city alone,” says Prof. Jacobson, who teaches at Stanford University and directs the university’s atmosphere and energy program. “But sea walls don’t reduce storm surge, they don’t reduce wind speed, and they don’t pay for themselves,” Prof. Jacobson says.
New York City plans to spend $20 billion over 10 years to improve the city’s ability to withstand another major storm, according to the mayor’s Office of Management and Budget.
Prof. Jacobson says that New York should devote some of that money to seeding private investment in a 20-mile array of wind turbines off Sandy Hook, N.J., near the entrance to New York Harbor.
He estimates that this array alone would cost about $210 billion, but says it could be repaid within 20 to 30 years by selling the electricity that the turbines generate.
View the original article here: http://online.wsj.com/articles/offshore-wind-turbines-could-tame-hurricanes-1411937788
By PETER S. GREEN