County considers rules on turbine lights

Potentially making wind turbines less noticeable at night, and easing some people’s annoyance with the turbine’s aircraft warning lights, Union County Board of Supervisors are considering wanting the lights activated only when needed.

No action was taken.

During their meeting Monday, supervisors continued their research and discussion on revising its wind turbine ordinance as a suspension of all wind turbine projects is in effect until Dec. 10. The ordinance has been in use since 2019 when turbines were erected in the northwest region of the county. There have been proposals to expand the number of turbines in Union County influencing the supervisors to review rules.

“There are some light mitigation systems,” said Supervisor Dennis Hopkins. “There are several entities, Kansas, Minnesota, North Dakota, Washington, Colorado; a lot of states have already started introducing light mitigation. The biggest two concerns I here are noise and the lighting.”

Hopkins said he has been told stories of people who drive at night north from Creston on Cherry Street Road notice the aircraft warning lights on turbines; those in Adair County.

“It makes it difficult for them. It bothers them,” he said.

Lights can be altered to only be activated when aircraft are flying through the region.

“It wouldn’t be a constant flash all the time,” he said.

Synced with the airplane’s radar system, the lights would be activated only when the aircraft is flying through a certain area. The aircraft detected would be ones that can land and take off from Creston’s airport. Commercial flights, like those from Des Moines International Airport, would not need the lights mainly because of those plane’s typical elevation at the time in the turbine area.

Hopkins said for the cost to be more effective, the detection system would have to be linked to a certain number of turbines. There will be a cost to retro-fit the wind turbines or add the devices to new turbines.

“It still doesn’t stop them,” Hopkins said about the wind turbines. “It just makes it more digestable for the people that don’t like them. It helps offset some of that.”

Supervisor Rick Friday said he struggles with night vision and driving. He said his vision conditions are “horrible” when seeing the wind turbine lights because of cataracts.

“I’ll avoid it. You have a light coming in from different directions,” he said.

Francine Ide, who has been offering information about turbines to supervisors, said she knows a person who has physical side effects because of the warning lights.

Supervisor Dennis Brown said he has heard from people who see the lights some 20 miles away.

“Even the people who don’t live in proximity to them complain about the constant flashing lights,” he said.

In a related issue, supervisors discussed setbacks with turbines specifically for what is called flickering. That is what happens when shadows cast by the turbine tower or the blades. When the blades are turning, the shadow cast constantly repeats and moves as the sun changes location.

Brown and Friday are in favor of setbacks of seven times the total height of the tower, including the blades, from property lines. Hopkins has suggested at least 3,281 feet.

Friday said he has found research about flicker which state 2,624 to 4,347 feet setbacks have still caused flickering. The potential of flickering is based on the location of the sun, as it changes during the daytime during the year, and clouds.

“It is very annoying, you can’t get away from it,” Friday said. He compared flickering to strobe lights in Halloween season haunted houses. He knows of people who have physical side effects from strobe lights.

“I could see how this, on your own home, how it could be very annoying,” Friday said. The farther the setback, the less potential for flickering, he added.

Hopkins added with setbacks at 3,281 feet, flickering “in a worst case scenario” happens from 10 to 29 hours per year.

“That’s less than two total days,” he said. “You’re talking a very minimal amount.”

Supervisors also discussed financing requirements for decommissioning, when a turbine is no longer needed. Hopkins had suggested $50,000 per kilowatt of the turbine’s capability. A 5K turbine would need $250,000 reserved. Supervisors favor reviewing decommissioning costs on a yearly basis expecting costs to change from the prior year.

Friday said Monday was likely the last workshop for wind turbines. Public hearings for the revised ordinance will be scheduled. Superivsors have not yet considered any dates.