Study Finds Wind Turbines ‘Slow Down’ Hurricane

OCEAN CITY — While the effort to develop an offshore wind energy farm just 30 miles off the coast of Ocean City continues to plod steadily forward, a new study released last week suggests offshore wind farms of a considerably greater size than the one proposed off Maryland’s coast could significantly lessen the power and mitigate the damage caused by hurricanes and other major coastal storms.

Late last year, the federal Bureau of Ocean Energy Management (BOEM) announced the lease of Maryland’s designated Wind Energy Area, an 80,000 acre tract of open ocean roughly 10 to 30 miles off the coast of Ocean City would be put out for bid early in 2014. Already, one major player, Virginia-based Dominion Energy, announced its intention to bid on Maryland’s wind energy area and others are expected to soon follow suit.
Just last week, a study released by Stanford University, in partnership with the University of Delaware, suggests offshore wind farms with thousands of turbines, could siphon away the energy from hurricanes and coastal storms and significantly reduce peak wind speeds and lower storm surges. Noted Stanford civil and environmental engineering professor Mark Jacobson conducted the research with the help of University of Delaware professors Cristina Archer and Willett Kempton.

During the study, a computer model simulated the potential impact of a vast offshore wind energy farm stretching for miles on a major hurricane bearing down on the coast. The model simulated Hurricane Sandy in 2012 and Hurricane Katrina in 2005 and determined the presence of a significant wind energy farm off the mid-Atlantic coast and the Gulf coast respectively could have reduced wind speeds by as much as 92 percent and storm surge along the coast of up to 79 percent.

It’s important to note the Stanford study simulated a wind energy farm with thousands of turbines lined up for several miles along the coast. However, the proposed offshore wind energy farm off the coast of Ocean City would likely have less than 100 turbines and possibly as few as 40. However, the study has relevance locally if a vast network of offshore wind energy farms all along the East Coast is considered. Currently, wind energy farm projects in Virginia and Delaware are slightly ahead of Maryland’s proposed project.

“We found that when wind turbines are present, they slow down the outer rotation of winds of a hurricane,” said Jacobson. “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.”

For Hurricane Katrina, the study’s model predicted the presence of a vast offshore wind energy farm off the Gulf Coast would have resulted in a wind speed reduction of as high was 98 miles per hour and a 79-percent decrease in storm surge. The figures generated for Sandy were less pronounced with wind speed reductions of up to 87 miles per hour and storm surge reductions as high as 34 percent.

In the study, Jacobson acknowledged there was some resistance in the U.S. to installing even a few hundred wind turbines, much less than the thousands outlined in the study. However, the environmental and energy efficiency benefits coupled with the added benefit of potential storm force reductions should stimulate future development, he said.

“The turbines will also reduce damage if a hurricane comes through,” he said. “These factors, each on their own, reduce the cost to society of offshore turbines and should be sufficient to motivate their development.”