Officials Work to Resolve Wind Energy, Radar Dilemma


US Defense Department officials are reaching out to academia and the energy industry to strike a balance between its support for alternative energy sources and its need to protect national security.

Dorothy Robyn, the department's deputy undersecretary for installations and environment, outlined the dilemma at a hearing before the House Armed Services Committee's readiness subcommittee June 29.

The department strongly supports the development of renewable energies – leaders have called America's dependence on foreign oil a national security issue -- and it is a recognized leader in the use of solar, geothermal and wind to produce energy, Robyn said. However, she added, military leaders also have found that the increasing use of wind turbines is taking a toll on the aging radar systems the military uses to, among other things, track threatening aircraft over the United States.

The situation was highlighted March 1 when the Federal Aviation Administration, which owns the radar, filed an objection to a proposed 338-turbine wind farm in north-central Oregon on behalf of the North American Aerospace Defense Command and U.S. Northern Command, which said the wind turbines were disrupting radar. The commands, which are collocated in Colorado, are responsible for aerospace warning and control and protecting the continent, respectively.

The department contracted the Massachusetts Institute of Technology to study the Oregon wind farm issue. MIT researchers found that the turbines disrupted radar as much as 20 percent of the time, frequently giving false positive readings, according to the report it released to the subcommittee. Wind farms disrupt radar by blocking microwave signals from reaching intended targets and by creating unwanted reflections or "cluttering" of radar signals, they said.

The department withdrew its objection to the Oregon project, which had been in the works for five years, after MIT discovered the problems could be mitigated with adjustments to the radar settings and modifications to the systems.

Most existing wind turbines have not disrupted military radar, Robyn said, but as the alternative energy source grows in usage, so, too, will the disruption problems like those created in the Oregon project.

Moving forward, Robyn said, the federal government needs to identify such projects earlier than the current 30-day notification deadline to mitigate potential problems without undue disruption to the projects. Also, she said, federal departments and agencies need to give more attention to the issue, and aggressively work to upgrade the radar systems, many of which were built in the 1960s.

The Defense Department has sharpened its focus on the issue by creating a director of operational energy position to serve as a central point of contact, by reaching out to the energy industry for collaboration, and by directing installation commanders to engage with local and regional planning officials on projects in development, Robyn said.

Source: US Department of Defense