In wind farm areas, most people will tell you that after a few weeks, the turbines kind of fade into the background and people stop noticing them.
One exception to that is the FAA required red lights that flash at night for aircraft safety.
New technology that will become standard on new wind farms going forward will greatly mitigate that effect.
If you drive across Iowa at night, you might encounter a series of coordinated red lights flashing in the sky.
Greenwood: “It looks like a whole bunch of fireflies lighting up at the same time.”
Geoff Greenwood is with MidAmerican Energy, which operates 3,400 wind turbines across the state.
Red lights are placed on top of the turbines to prevent pilots from crashing into the structures, which can be more than 200 feet tall.
But that flashing lights up the night sky, which some people find annoying — so at three of its wind farms, MidAmerican Energy has installed a radar system that scans for nearby planes.
When a low-flying plane is detected within a few miles of the turbines, the warning lights start to flash.
But when the skies are clear, the lights stay off — and Greenwood says that since the system was installed, they stay off about 95% of the time.
Greenwood: “It has a dramatic impact on the nighttime sky.”
He says safety is the priority, so if the radar system fails, the lights turn on automatically.
After testing the technology for a year, the company will look to install it at other wind farms — keeping pilots safe while reducing light pollution.
Greenwood: “This gives us the best of both worlds.”
“It has a dramatic impact on the nighttime sky” What about the daytime sky? I ask again: why are windmills white? Why aren’t they blue, or green? Cellphone towers are whatever color the background is. Once, driving from LA to Las Vegas, I had no idea I was coming upon a large cellphone tower until I was practically on top of it.
I suspect windmills are white for the same reason there are flashing red lights atop them: for the benefit of low-flying airplanes. Which begs the question: why aren’t we then painting the tops of trees white?
One possibility is that white turbines will be cooler in the daytime potentially lowering the rate of degradation of the bearings.