Increasing the amount of electricity we get from renewable sources such as the sun and wind is a national priority and a state mandate. Among the many obstacles to getting that done — opposition to new transmission lines, worries that solar plants will harm endangered species, conflicts over land use — one has until recently remained largely off the public radar screen. But the radar screen is precisely the problem: Wind farms interfere with commercial and military radar systems.
In 2009, wind projects that would have produced a combined 9,000 megawatts of power were shelved or stalled after the Department of Defense or the Federal Aviation Administration raised concerns about radar, according to the New York Times. That's nearly as much as the power generated by wind farms that were actually built last year. The Mojave Desert is a particular trouble spot because of the many military air facilities in the region, and several proposed projects there have been withdrawn after hitting turbulence from the military.
Modern wind farms plant rows of spinning turbines on towers up to 400 feet tall, sometimes causing aircraft passing overhead to appear to vanish from radar screens. It's a serious problem but it's not insurmountable, as wind developers in Solano County recently showed.
After officials at Travis Air Force Base raised objections to a wind-power project in the nearby Montezuma Hills, the project's developer and the Air Force reached a highly unusual agreement to share data. An independent consultant used the information to demonstrate that the turbines wouldn't interfere with the base's radar system, and the Air Force withdrew its opposition.
Unfortunately, that kind of cooperation is rare. More typical is the situation described by JASON, an independent advisory group that does scientific consulting for the U.S. government, in a 2008 report on wind farms and radar. It suggested that the military's preferred response to proposals for wind projects near bases was "to declare encroachment and block installations of offending turbines, rather than attempt to find technical means of ameliorating the turbine impact."
Such technical solutions exist, but they're expensive. The best one is simply to replace outdated military radar systems with more modern equipment that isn't fooled by wind turbines, but there are others, such as using high-tech coatings on turbine blades that don't interfere with radar. What's really needed is for the Obama administration to work out a coherent plan for dealing with such conflicts between its energy and national security priorities.