Wind power growth gated by radar conflicts

February 4, 2010 9:43 AM PST

by Martin LaMonica

WASHINGTON--The most well known obstacles to installing wind turbines are complaints over their visual impact and the potential for birds and bat deaths. But conflict with radar systems have derailed over 9,000 megawatts worth of wind capacity--nearly as much as was installed in the U.S. last year.

(Credit: U.S. Air Force) "We're not going to put up more wind (in many locations) without conflict because radar systems and wind systems love exactly the same terrain... which is where the wind is at," said Gary Seifert, a program manager for renewable energy technologies at the Idaho National Laboratories during a presentation at the RETECH conference here on Thursday. "It's really causing a challenge to meeting long-term goals."

The problem is wind farms create "cones of silence" above them, making it difficult for primary radar systems to detect airplanes when they fly over them, Seifert explained. Planes with transponders can communicate with air traffic control towers, but smaller planes don't all have transponders.

Because of radar issues, 2,100 megawatts of wind projects were held up, 5,100 megawatts were deferred, and 2,100 megawatts were abandoned, he said, citing data from a survey done by the American Wind Energy Association. Last year, 10,000 megawatts were installed in the U.S.

Seifert said research could lead to technical fixes to address the problem, including upgrading the software within radar systems to better discern between a spinning turbine blade and an airplane. Turbine blades can also become more "stealthy," or less reflective and detectable by radars systems, he added.

Working with stakeholders early on in a wind development project can also address issues.

But the problem is that it's unclear "who owns the liability of the sky," he said. Homeland Security, the Department of Defnese, and the Federal Aviation Authority could all be involved in addressing the situation.

The fear for wind developers is that a delay to study radar-related complications could make a project unprofitable, he said.