MidAmerican testing system to keep wind turbine warning lights off until needed

DES MOINES — Residents of four Iowa counties may notice there are no red lights now blinking in the night sky. MidAmerican Energy spokesman Geoff Greenwood says the company is testing a new radar system where the lights on some 200 wind turbines in Adair, Audubon, Cass, and Guthrie counties are only on when needed.

“The lights are off all the time unless our system detects an aircraft in the area within about three miles of the wind farm. And so this system, we expect will reduce nighttime lighting by at least 95%. So it’s going to be a dramatic drop in nighttime lighting,” Greenwood says. He says the commercial jets that regularly fly over Iowa at high altitudes would not set off the system.

Greenwood says warning lights have been on top of wind turbines since they started putting them up.in 2004 “Anything that’s a few hundred feet up into the air,  the FAA requires warning lights so pilots know that there is an obstruction in the area,” he explains. “So as you drive in rural Iowa at night, you’ll notice all these red flashing lights.”

He says they just recently started testing the system for the Eclipse the Morning Light wind farms in the four counties. “Area residents would have noticed that the lights were off and probably wondered what’s going on here,” he says. “Well, that’s what’s going on we’re testing this new system. And we expect that from here on out the lights should be off most of the time at these three wind farms during nighttime hours.”

Greenwood says they are looking for input on the change from residents and pilots. “We know the FAA has signed off on this and believes it’s safe, we’re confident it’s safe. It will protect nighttime skies for pilots, and make sure that they are safe, but it will also darken the nighttime skies. And that’s why we think that the communities where we’re testing this will really be happy with the way this turns out,” he says.

He says they will run tests throughout the next year to see how everything works. “How weather may impact it, how things like ice may impact it. It just makes sure that it works as advertised,” Greenwood says. “And it’s something that we would like to look at for other Mid American wind farms.” Greenwood says it may be a system they used with new wind farms and they could also look at a system for other wind farms as they take down components and replace them with new ones.