Dodge County has 36 massive wind turbines in Dodge County to boost the region’s clean energy supply.
But they were built less than 20 miles from a weather radar station, and the project has had an unintended consequence.
Something unusual came up when the blades started spinning: the radar screens went haywire. A permanent signal appeared on the maps that had forecasters baffled for a while.
The bizarre illusion looked like a storm. But there was none.
What was it about the operation of the wind farm that tricked the meteorological computers?
How Dodge County has to dodge a clash of tech
The Butler Ridge Wind Farm in Dodge County, Wisconsin, features an impressive 36 giant turbines.
Its neighbor is the KMKX Doppler radio station in Sullivan, operated by the National Weather Service.
It’s an essential facility for forecasters. They use the precise data from the dish daily to warn local communities about the weather.
But a high-tech conflict appeared on the horizon that no one predicted.
The wind farm was placed smack-bang in the middle of the radar station’s line of sight. The proximity of just 20 miles was a major problem for the uber-sensitive radar dish.
The instant the blades started doing their work, the screens in the radar control office started glitching.
Official weather maps all of a sudden flashed with a mysterious signal. And it wouldn’t go away.
What was the phantom signal all about, and how did it tie in with the wind farm?
Radar vs. solar: A blind spot in the forecasting
The “ghost in the machine” turned out to be more serious than a glitch in the system.
The radar was picking up a huge cluster of energy in the shape of the Butler Ridge Wind Farm footprint. The pattern matched perfectly.
The KMKX Doppler radar beam can’t see past the steel turbines. It’s the nature of how radar works.
The turbines create a “shadow” in the readings behind the facility, and the result is a meteorological blindspot.
There’s a real danger involved, according to the National Weather Service. It warns that localized interference hides actual potential hazards.
For example, a developing flash flood, thunderstorm, or even a tornado could be missed. This puts real lives at stake.
There’s another kicker: this is not the only place with the same problem. Turbines are causing havoc with radar and changing localized weather all over the world.
NOAA and the wind energy industry as a whole are working towards solutions to the challenge.
What can be done to make sure that public safety and clean energy coexist without clashing?
What specific effect leads to rain on the radar?
Doppler radar science has the answer.
Weather stations work by sending out beams into the atmosphere. When they hit an object as they’re traveling through the air, the energy bounces off.
The weather part comes in when they encounter rain, hail, or snow. The signal gets scattered, and a fraction is reflected back to the dish.
Doppler shift comes into play when objects are moving. The frequency of the beam changes as it returns from something in motion.
The computers on the receiving end use this info to calculate the speed of an object. And this is how the 36 turbines at Butler Ridge are sending faults to the forecasters.
Radar needs to up its game
Wind turbine blades reach up to 180 miles per hour as they spin.
Strangely, the fast motion mimics the signals of a heavy band of precipitation. In some instances, the motion even alters the regional weather patterns.
Radar systems are not sophisticated enough to tell the difference. So the KMKX station’s automated radar computers threw up storm front data when there was none.
Will advances in engineering find a way to harmonize wind farms with weather prediction? Or should we just get used to less reliable forecasting of potential disasters?
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