By Scott Williams of the Journal Sentinel

NOAA
A small part of the electromagnetic energy radar is reflected back by
the rotating turbines of the Butler Ridge Wind Farm in Dodge County.
The radar processes this “returned energy” as an area of precipitation
and plots it on the map.

 

The National Weather Service has issued a new kind of warning because
of a Dodge County wind farm that is disrupting the agency’s ability to
monitor storms in southeastern Wisconsin.

The wind farm’s giant turbines – each as wide as a football field and
as tall as a 20-story building – are sending false storm signals to
the government’s weather radar system.

Weather service officials say they see no significant public safety
threat, although they say the wind farm has caused radar interference
and could confuse some storm watchers.

Meteorologist Marc Kavinsky said the approaching summer storm season
will be the federal agency’s first opportunity to gauge the wind
farm’s full impact.

“It’ll be interesting,” he said. “I’m hoping the effects will be
minimal.”

Located just outside the Dodge County community of Iron Ridge, the
wind farm includes 36 turbines that began operating over the past few
months, generating electricity for several surrounding communities.

The farm is about 30 miles north of the National Weather Service
office in Sullivan, which provides radar coverage and severe weather
alerts across a 125-mile radius that includes all of southeastern
Wisconsin.

Iron Ridge Fire Chief John Beck said he has heard residents complain
that the wind farm was disturbing their television reception, but he
had no idea it could affect the weather radar.

“Somebody should’ve worked out that problem a long time ago,” Beck
said, noting that wind energy has been under development for many
years.

The owner of the wind farm, Babcock and Brown Ltd., just recently
became aware of the situation in Dodge County and intends to discuss
it with the weather service, company spokesman Matt Dallas said.

Dallas said the company has not encountered a similar problem with any
of its other 24 wind farms operating throughout the country.

“It’s definitely new to us,” he said.

Known as the Butler Ridge Wind Farm, the Dodge County facility has
come under criticism and scrutiny in the past.

Before it was approved by Dodge County officials, environmentalists
complained that the operation would threaten surrounding wildlife. The
Federal Aviation Administration later stalled the project before
agreeing that it would not compromise military aircraft radar.

The turbines, which are 300 feet wide and 260 feet tall, were
installed starting last summer and began operating late last year.

Michael Vickerman, executive director of the wind energy advocacy
group Renew Wisconsin, said it is among 10 wind farms statewide with a
combined 327 turbines, capable of powering 100,000 households. Many
more wind farms are in the planning stages, he said.

Saying that weather radar interference has never been a problem before
in Wisconsin, Vickerman said it almost certainly can be managed and
should not slow the growth of the alternative energy resource. But he
added, “The wind industry has to take this problem seriously.”
Showing up quickly

Weather service officials said they began to notice the problem almost
immediately after the Dodge County wind farm began operating.

According to a report on the agency’s Web site, the spinning wind
turbines have presented “persistent interference” that mimics storm
systems and could “negatively impact warning effectiveness” when real
storms move into the area.

Rusty Kapela, the agency’s warning coordinator meteorologist, said
officials have tried to adjust the radar system to block out the wind
farm readings.

But because it affects such a small geographic area and is easily
recognized by the weather service’s trained experts, Kapela said, the
situation is not a significant problem. It was posted on the Web site
only as an informational report for the general public, he said.

“It’s just interesting science stuff,” he said. “In the grand scheme
of things, it’s just a minor blip.”