Wanted: Flat ground with a clear line of sight to the horizon and few obstructions.
That is an ideal spot for a wind energy farm. Coincidentally, such topography is also ideal for military and Federal Aviation Administration radars.
The clean energy industry has found itself clashing with the Defense Department and FAA in recent years over the location of windmills, which are sprouting up across the nation from the prairies to the shores.
The crux of the problem is radar clutter. Both the moving blades and the towers they sit on can create false readings. Personnel monitoring screens at military bases, training facilities or other installations that watch U.S. airspace could mistake a windmill for an aircraft. Interference can also create blind spots that pilots of a hijacked airplane, or a small aircraft, could use to avoid detection.
Not only are the turbines becoming more numerous, they are becoming taller. The longer the blades, the more electricity they can produce at a cheaper kilowatt-per-hour cost. However, the increasing heights mean more radar clutter.
Industry advocates are now looking toward Great Britain to serve as an example of how the military and commercial interests can work together to solve the problem. That nation was recently forced to tackle the windmill radar clutter issue in both the technical and policy realms.
“What happened in the U.K. is the U.S wind industry’s model for the way we would like to see things proceed here,” said Tom Vinson, director of federal and regulatory affairs at the American Wind Energy Association.
The British realized they had a problem when the government set a goal requiring that 20 percent of the nation’s energy come from renewable resources by the year 2020, said Bill Troia, Lockheed Martin international business development manager for long-range radars. Offshore wind farms were a large part of the plan. Realizing that they were going to cause radar interference, the Ministry of Defence began rejecting almost all applications.
“It just so happens where you want wind farms is a perfect place for where you want radars — flat, open, good visibility to the horizon. That is also a good area for wind to come in,” Troia said.
The United Kingdom is a relatively small nation where there is keen competition for this kind of real estate. Upgrading radar software was tried first, and in some cases, that eliminated the false alarm problem, but it didn’t clear up the blind spot issue, Troia added.
Vinson said Britain’s wind energy association — Renewable U.K. — negotiated with the Ministry of Defence and the Civil Aviation Authority to produce a memorandum of understanding that laid out a process for early engagement between wind farm developers and the agencies. It set clear timelines for resolving conflicts.
The United States has yet to develop such policies, Vinson said.
A recent House Armed Services Committee readiness subcommittee hearing on the subject brought some attention to the differences between government and industry.
The FAA, which has the power to review and reject windmill licenses, is receiving about 1,500 applications a week, said Nancy Kalinowski, the FAA vice president of systems operations services at the air traffic organization. Each tower requires a separate license. The Defense Department also has the right to review and object to applications before they move forward.
Rep. Randy Forbes, R-Va., repeatedly asked Air Force Maj. Gen. Lawrence Stutzriem, director of plans, policy and strategy of U.S. Northern Command, if the Defense Department was willing to accept a decrease in military readiness to support national energy initiatives. After several attempts to receive a straightforward answer, Stutzriem finally agreed to share his personal thoughts, while noting he was not authorized to speak for the department.
“In my opinion, homeland defense is our top priority … and it should take precedence,” he said.
Kalinowski backed him up and said she was authorized to speak for the FAA. It would not accept any degradation of radar systems.
Dorothy Robyn, the Defense Department’s deputy undersecretary of defense for installations and environment, said, “I don’t think we intend to accept a significant level of reduction of military readiness.”
Charlie Walker, Lockheed Martin’s domestic business development manager for long-range radars, said in an interview that the security issue became serious in the wake of the 9/11 hijackings. The FAA has short-range radars for traffic control purposes that extend some 50 to 60 miles from each airport. The problem is the long-range FAA radars that are located in various spots across the United States that are designed to track airplanes and jets between airports. In the late 1990s, the agency began to lose interest in the radars as it began to rely on beacons to keep track of aircraft as they traveled between cities. But one of the first actions the 9/11 terrorists took after hijacking the jetliners was to turn off the beacons.
After 9/11, the Defense Department wanted to fund and maintain the long-range radars for security reasons. They are still FAA assets, but the Departments of Defense and Homeland Security are the primary users of the data. The radars are needed to track jetliners in the case of a beacon being cut off. Small aircraft, which could potentially be used for terrorist attacks, do not normally carry the beacons.
At the hearing, Robyn accused the industry of lining up investors for projects and choosing sites before applying for licenses. The key to fixing the problem is learning about projects early and working with developers to come up with mitigation strategies, whether these solutions involve moving the turbines or improving the radars, she added.
Vinson said this is an example of a policy issue that the British have worked out.
U.S. developers are not required to submit the paperwork stating the exact locations of wind turbines until 30 days before breaking ground. That, Vinson concedes, is far along in the process. The FAA, however, doesn’t have the human resources needed to review proposed sights in advance to give developers a heads up on any potential issues.
The agency wants the exact location of each individual turbine when the paperwork is filed. Most developers don’t want any surprises and do begin to engage with local base commanders or other military authorities as soon as they can, Vinson said. But it’s not always clear who is in charge and who they should contact.
The department is not always responsive, he said. Some base officers are helpful in finding solutions — others aren’t. And “if you talk to one part of DoD you might get one answer and if you talk to another part, you might get another answer…. It’s been kind of ad hoc,” Vinson said. “That’s one thing we’re trying to solve and DoD is trying to solve on their side as well.”
Along with a plan for early engagement, the British also set a research and development agenda.
Robyn testified that the Defense Department needs to spend more dollars on finding remedies to the problem, and consider picking up the pace of upgrading radars.
In Britain, Lockheed Martin was brought in to see if its long-range radar, the TPS-77 could be a solution. During a military exercise in Denmark, a mobile version of the radar was set up near a wind farm and a British pilot flew behind and above the towers to see if it could distinguish the aircraft from the blades and ensure there weren’t any blind spots. The test was deemed a success and the radar has been purchased to replace some of the older British systems that couldn’t cut through the clutter.
One question the U.K answered that hasn’t been addressed in the United States is “how good is good enough,” Walker said. The Ministry of Defence decided it didn’t need a radar so powerful that it could pick up objects flying among the turning blades — it would be unlikely that a pilot could successfully fly so close. However, it did want detection capabilities above and behind the towers.
“We’re not trying to convince anybody that the solution is to blanket the whole country with our radar — that would be really nice — but we’re offering our radar as a solution for the time being,” Walker said.
Vinson said there won’t be a “one size fits all” technical solution to solving the clutter problem.
“We need to do a lot more research to understand what the technical solutions are,” he said. The Defense Department will also want to validate any solutions before officials are comfortable deploying them, he added.
In some cases, it may only require a software upgrade. If the radar is based on 1960s era analog technology, then it might be time to swap out the whole system with a new radar, he suggested. There are also proposals to coat the blades with the same kind of material that makes stealth fighter aircraft invisible to radar.
“There are so many different kinds of radars in use,” Vinson said. “They have different missions, the bases have different missions, and then there’s the impact of the terrain. There is not a single solution that is going to work everywhere.”
The association would like to see a more coordinated federal research agenda. The Air Force, the Department of Energy’s federally funded labs, and industry are all looking for technical solutions. The White House office of science and technology policy is currently undertaking a review to try to get a handle on what all these departments are doing, Vinson said.
The final question the United Kingdom had to work out is the funding.
The TPS-77 radar, for example, can cost anywhere from $14 million to $20 million. Wind Farms are for-profit enterprises. Why should taxpayers foot the bill to replace or upgrade long-established government radars that have been in the same location for decades?
In one case, wind energy developers in the United Kingdom banded together to pay for about half of the cost of a TPS-77 radar, Troia said. An agreement was worked out so they did not have to come up with all the money up front. They will start making payments when the farm is up and running.
Vinson said U.S. wind farm developers are willing in some cases to pay for part of the costs of software upgrades, or even full-scale radar replacements. That has happened at least one New England based offshore wind farm, he noted. Fifty or perhaps 75 percent of the costs could be shared, but he stopped short of saying that 100 percent of the expenses should be paid by developers.
There is a policy problem yet to be worked out, though. The Defense Department doesn’t have the statutory authority to accept money from developers. For the FAA, that is not a problem.
Vinson said the association will continue to go to the agencies and Congress to pitch the U.K. model as a solution.
Walker added: “Obviously, the Brits found a way to solve this problem where everyone wins. The developer gets to put his wind farm where it can be profitable. He creates jobs, green energy, and the MoD gets to at least maintain their surveillance capability.”