ELIZABETH CITY, N.C.
The Navy agreed last year to let Spain-based Iberdrola build the largest wind farm in the southeastern United States close to a radar system in Chesapeake that monitors potential threats to national security.
Navy officials have hammered out an agreement with the company, but it will take a year of construction and testing to determine whether the 104 turbines – each nearly 500 feet tall – clutter vital radar signals. Leaders last week broke ground on the project, west of Elizabeth City.
The radar system is part of Naval Support Activity Northwest Annex in southern Chesapeake. It monitors more than 10 million square miles of air space for the military and law enforcement agencies that track drug trafficking as far away as South America.
The Navy requires examination of any project within about 30 miles of the site. The $400 million Iberdrola project site begins roughly 12 miles away.
Wind turbines can clutter radar images, disrupting aircraft detection or producing false readings, according to a Department of Defense report. Officials have raised concerns before: In February 2014, U.S. Marine Corps Gen. John Kelly, head of the U.S. Southern Command, told Congress the North Carolina wind farm “likely will adversely impact” the Navy radar in Chesapeake.
He said the Northwest Annex hosts the only radar capable of tracking illegal aircraft in Latin American and the Caribbean, where drug trafficking and organized crime infiltration to the United States is on the rise. The military and developers are working on lessening the impacts, he said, but he added, “I have little confidence they will succeed.”
Since then, the Navy has worked with Iberdrola to mitigate the effect of the turbines, something the Pentagon report says can be done through location selection, “tuning” the radar and other changes. Reached by phone, Navy spokeswoman Katisha Draughn-Fraguada said, “It is not anticipated the turbines will interfere with the radar system.”
Iberdrola has agreed to erect turbines where they would cause the least interference, generally to the south end of the 22,000-acre tract straddling Pasquotank and Perquimans counties, said Craig Poff, a regional director of business development for Iberdrola Renewables, the energy company building the wind farm.
Miles of turbines, each with three spinning blades nearly 200 feet long, will generate more than 200 megawatts – enough to power 60,000 homes. Amazon Web Services plans to buy the electricity.
The company is required to run tests with the Navy to ensure the spinning blades do not disrupt the Northwest Annex mission.
The Navy has the right to shut down the turbines in case of a national security threat, according to the agreement between the Navy and Iberdrola. The Navy would also screen foreign companies that might install or repair equipment in case of security concerns, the agreement says. The Spanish firm Gamesa will manufacture the turbines.
“The national security threat must be resolved prior to allowing access to the site,” the agreement says.
The federal government includes concerns like that in contracts all over the world, Poff said.
The Department of Defense Siting Clearinghouse reviewed 521 wind projects last year nationwide for federal facility interference, including two in North Carolina and two in Virginia, according to the agency’s 2015 annual report.
In all, 2,594 energy-related projects including transmission poles and lines and solar structures were reviewed last year, a 25 percent increase from the previous year. Of those, 2,332 were approved.
The report did not say how many of the 521 wind projects reviewed were approved.