Thinking Tech

Do wind farms lower military readiness?

Posting in Energy

The FAA and the Department of Defense say yes.

Members of a House Armed Services sub-committee this week listened to complaints from both the FAA and the DOD about the spinning blades of wind turbines and how they interfere with radar signals that detect flying aircraft -- a problem if these aircraft are flying by a wind farm, and an even bigger problem if the wind farm is located near a military base.

The radar may detect spinning wind turbine blades as a 747, and the signals from smaller planes are drowned out.

The FAA also complained that wind turbines confuse next-generation weather radar, which interprets the spinning blades as storms and makes it harder for air traffic controllers to tell pilots what to expect if they're flying near a wind farm.

Emotions on wind farms and radar ran especially high in March, according to Dr. Dorothy Robyn of the DOD, when the FAA halted construction on the Shepherd's Flat wind farm in Oregon -- projected to be the largest land-based wind farm in the world -- even though the project was already more than five years old and new wind turbines were about to go up.

NORAD and the U.S. Northern Command feared that the turbines would interfere with their long-range surveillance radar, Robyn said -- and hence, the defense of the U.S. homeland. Shepherd's Flat's backers -- General Electric and Caithness Energy -- which had already spent hundreds of millions of dollars on the project, were not pleased.

On April 30, after intense discussions, the defense agencies withdrew their objections. They decided the new turbines' impact on their radar wouldn't be as bad as they thought. But they're also expecting scientists at MIT's Lincoln Lab to come up with new ways to handle radar interference before the new turbines are up, 18 months from now.

The real problem here, according to wind turbine manufacturers, who are also talking to Congress, is that 80 percent of U.S. radar is badly outdated. It's 30 to 60 years old, and it needs to be upgraded or replaced.

The U.S. is also behind on technology to capture wind, they say -- stealth composite blades, for instance, which absorb radar signals, are used in Europe but are not validated for use in the U.S. Other technology can help reduce environmental noise so radar can read objects more accurately.

Here's another problem -- the process for deciding where to place wind farms dates back to the 1960s, when the DOD and the FAA were able to evaluate a construction project within 30 days because all they had to worry about were tall buildings.

New legislation due next year, which aims to avoid another Shepherd's Flat debacle, is supposed to speed approval for wind farms by creating a single place within the DOD to review applications. Details are still being worked out.

In the meantime, applications for wind farms are pouring in to the FAA, partly because of federal stimulus money -- this year the FAA has over 25,000 applications, eight times as many as in 2004.

Radar and wind farms are now competing for available land, and the FAA can't afford to keep up. Here's what the FAA's Nancy Kalinowski told the Armed Services subcommittee:

Lease holders who currently have primary radars are now being offered substantial financial incentives not to renew their leases with the FAA and instead, lease to companies that want to install wind turbines.

This puts the FAA in the undesirable position of having to condemn property at fair market value to avoid losing the use of the navigational aid.

The call for the FAA to simply move its radars to accommodate requests to install wind turbines fails to take into account that this is not a realistic option for a number of reasons. The FAA cannot take down a radar without an unacceptable loss of coverage. Even assuming an acceptable, alternate site could be identified, the radar could not simply be moved. Rather, a new radar would have to be installed at the new location.

The reality is that the FAA does not have extra radars available for replacement and there are no spare long range radars. Even if a new radar were available, moving the radar site would require changes to the national airspace system. Airways, reporting points, and airspace fixes are parts of the airspace system that could be impacted. Depending on the situation, such changes could require regulatory action.

The bottom line is that moving radars around the country is a costly, disruptive, unacceptable, and unworkable proposition. It may sound simple, but in fact, it is not something the FAA can accommodate or the taxpayers can afford.

Wind farms could move away from radar, off-shore, but those projects have problems too -- several environmental groups last week filed a lawsuit against a proposed wind farm off Cape Cod. They're worried about protecting whales and migratory birds from spinning wind turbines.

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Deborah Gage

Contributing Editor

Contributing Editor Deborah Gage has written for the San Francisco Chronicle, Minnesota Public Radio, Baseline and various magazines and newspapers. She is based in San Francisco. Follow her on Twitter. Disclosure