New Interference on the Horizon for US Wind Power Development
by Jesse Broehl
Thursday 15 June 2006
Pittsburgh, Pennsylvania - At Tehachipi pass, a well-known wind farm in Central California, even the smallest wind turbine, the tips of its blades whirling at just the right speed, gives off a radar signal larger than that of a Boeing 747 Jumbo Jet, according to Gary Seifert, Program Manager, Idaho National Laboratory, who spoke at last week's annual US wind power industry conference.
At the same time, the US military is perfecting stealth technology so that some planes give off a radar signature no larger than a bird. This drastic mismatch, said Seifert, shows why military concerns over radar interactions with wind projects are putting the brakes on hundreds of megawatts of wind power development in parts of the country.
Siefert, a radar specialist, spoke to a well-attended session on radar-wind interaction at the American Wind Energy Association's (AWEA) recent annual WindPower conference held in Pittsburgh. The session was a last-minute addition to the conference lineup, as this issue has only recently posed an alarming new concern for wind development in the US.
"Recent action by some US government agencies to effectively halt development of many pending wind energy facilities could lead to a de facto moratorium on the development of wind power in the US," said a statement from the industry's major representatives, AWEA.
This stems from The National Defense Authorization Act for Fiscal Year 2006, signed into law January 6, 2006 (PL 109-163), which contained a last-minute amendment inserted by Senator John Warner (R-VA) requiring the Department of Defense to study and report on the effects of wind projects on military readiness.
A host of projects in the Midwest have been thrown into doubt pending completion of this review. Reportedly as many as 15 potential projects in the development pipeline were issued notices of "perceived hazard" from the Federal Aviation Administration (FAA), bringing progress to a halt.
Not only can many wind turbines give off a similar signature to that of an airplane on a landing approach, but wind projects can create radar "dead zones" above and behind a particular wind project, or "ghosting," whereby a second false image can be created, according to Siefert.
He stressed that the military and the wind industry are at a very preliminary stage in the process of working this situation out and that ultimately a middle ground will be found between the benefits of wind power and national security concerns. But he finished his speech with an ominous last remark.
"We have several thousand wind power megawatts in the ground within radar view. They're working OK together. Does that mean they'd be put in today if we had today's rules? Probably not."
A turning point of sorts occurred on the topic, following Siefert's overview, when a representative of the US Air Force, Lt. Col William Crowe, a high-ranking Airspace Policy Officer from the Pentagon, offered to act as an initial one-stop contact within the Air Force to facilitate the process for wind project developers to inquire about how their particular projects might be affected. He says a larger effort is under way to formalize a military contact covering all branches but he was only there to represent the US Air Force.
"We're trying to establish a standard process so that wind developers can hit one person in the Department of Defense," Lt. Col. Crowe said. "We're in process to achieve that and it's only in its infancy right now."
By all accounts, the original Congressional language was aimed at one project. However, DOD and the Department of Homeland Security (DHS) have decided to expand upon the original study directive and apply it to all proposed wind power installations in the United States. But only in the Midwest have projects actually been put on hold by the FAA - so far. Regional FAA offices have made the call to put these projects on hold.
David Luck, head of business development for Enexco, is just one of many wind power developers concerned about how this will impact projects currently in the pipeline. His company is the largest supplier of operations and maintenance for wind projects in the US with more than 4000 turbines currently under their watch. And he's a good example of a concerned developer that hasn't been able to get all the right facts and answers about this issue.
"It has a significant potential impact on all our projects, and it's such a new issue it almost came out of the woodworks," Luck said. " We're still working to understand the issue. If taken literally, it could eliminate thousands of megawatts of wind power."
The language Luck refers to is in an Interim Policy on Proposed Windmill Farm Locations, circulated on March 21, 2006 by the DOD and the DHS, that states: "[t]he DOD/DHS ... Interim Policy is to contest any establishment of windmill farms within radar line of the National Air Defense and Homeland Security Radars. This is to remain in effect until the completion of the study and publishing of the Congressional Report."
The key phrase is "radar line," or "line of sight," as others have put it. What has everyone so worried is that line of sight with radar can be broadly interpreted to an infinite distance from a radar facility. And the US military, as one might guess, has stunningly capable long-range radar systems with considerable range that could easily pick up signals from distant wind projects.
The study commissioned by Congress is supposed to evaluate this issue but the report is already overdue and there's no indication of when it will be completed.
"Right now this has a major unknown element to it," Luck said. "It's like a miniature version of the two-year 'wait and see' on the PTC," said Luck, referring to the wind power industry's challenge dealing with the federal government's on-again, off-again tax credit.
Even if certain projects are understood to impact certain radar facilities, there are technological and software solutions. For example, the operators of a particular digital radar facility can purchase an add-on software package that's designed specifically for interpreting the signals that wind farms produce. This has been employed in Europe - particularly the UK - with success.
Axel Albers, the Senior Scientist with WindGuard North America, has followed European experience with this issue as his firm's parent company operates primarily in Europe and only now has made a new push into the US wind market. Albers said initial radar concerns in Europe were widely overblown and in some cases politically motivated (a topic worthy of a separate article regarding the US situation).
"It has been figured out that, in most cases, concerns were not justified," said Albers.
And despite all the uncertainty on where this issue is going, and all the hushed talk about justification or political motivation, developers like Dave Luck think this will somehow work out in the end.
"We have a very active wind market here," Luck said. "The radar issue will sort itself out. So will the PTC, or at least people will figure out a soft-landing."