Curious Iowa: What happens to wind turbines after they’ve been decommissioned?

With Iowa being a leader in renewable energy, wind turbines standing hundreds of feet above the ground can be seen throughout the state.

And as the renewable energy grows, wind turbine structures are projected to grow taller to capture and produce more energy.

But as the stature and the number of wind turbines continue to grow regionally and within Iowa, more turbines are meeting the end of their lives. So, what happens to wind turbines after they are decommissioned?

That’s what one Iowan asked when they wrote to The Gazette’s Curious Iowa, a series that answers audience questions about the state and how it works.

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Jeff Danielson, vice president of advocacy for the Clean Grid Alliance, said developers plan out a turbine’s decommissioning process before a wind turbine is even built.

“It’s standard practice to begin with the end in mind,” Danielson said. “When wind farms are planned, there is a decommissioning process and it's common practice now to ensure that there's financing for the decommissioning.”

Danielson said this can include a development company having “post-financial guarantees” in place when a turbine reaches the end of its life, so there are apt resources available to take the structures down and restore the land around them.

Overall, however, Danielson said wind turbines seldom are taken down.

He said this is because wind turbines are most often “repowered” when they reach the middle of their life span to prolong their use.

With the average wind turbine being designed to last 20 to 30 years, Danielson said that the turbines will be repowered with replacement blades or new components of the structure’s nacelle, which is the large box at the top of the tower that sits behind the blades.

The “components replaced are more efficient and so the benefit of that is that you don't have to completely start over,” Danielson said. “They're built to last and they're also able to be modified as improvements are made.”

In the renewable energy sector, Danielson said wind turbines have only been around since the mid-1990s, making it a relatively young energy source.

With that, he said the circumstances where wind turbines are “completely decommissioned or completely taken down and disposed of still is rare.”

Sri Sritharan, chair of interdisciplinary engineering and professor of construction and environmental engineering at Iowa State University, said that when wind energy was first gearing up, the turbines were built with a life span of about 20 years.

Since then, researchers have prolonged a turbine’s life span by five to 10 years, he said, adding that the amount of kilowatts wind turbines have been able to produce has increased as well.

A push to recycle

Sritharan said there has been a significant push to recycle wind turbines and their blades across the wind energy sector.

According to the Department of Energy, about 90 percent of mass wind turbines and wind systems can be recycled.

Despite this, however, Sritharan said more research and development into wind turbine recycling is needed.

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“This is kind of an up-and-coming area in terms of technology development and how people would go about using them,” Sritharan said. “There are different materials getting used, and so the recycling concept varies to different degrees. … But there has been more and more effort put into improved recycling so that these components could be recycled.”

Sritharan said that more policy is needed to propel wind turbine recycling further.

“Then it becomes feasible,” he said.

In June 2024, a new wind turbine blade recycler opened in Fairfax.

The facility, REGEN Fiber, which is owned by owned by Alliant Energy subsidiary Travero, uses a mechanical process, instead of using heat or chemicals, to process up to 12 tons of material an hour.

The average decommissioned blade has from 3 to 10 tons of recyclable material.

Cindy Timlinson, senior manager of communications with Alliant Energy said that REGEN Fiber receives blades to recycle from around the country but most are from wind farms in the Midwest.

Jeff Woods, director of business development at REGEN Fiber, said the company developed a process to transform decommissioned wind turbine blades into “100 percent recycled high-performance reinforcement fibers.”

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“We saw a fresh new way to recycle the blades in an environmentally friendly manner that adds strength, flexibility and longer life to some of the world’s most widely used materials, including concrete, asphalt and composites,” Woods said in an email to The Gazette on Wednesday, Nov. 5. “Our patented mechanical process — no heat, no chemicals — saves energy and eliminates toxic byproducts, making the recycling process safer for workers and the environment.”

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Olivia Cohen covers energy and environment for The Gazette and is a corps member with Report for America, a national service program that places journalists in local newsrooms to report on under-covered issues. She is also a contributing writer for the Ag and Water Desk, an independent journalism collaborative focusing on the Mississippi River Basin.

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Comments: olivia.cohen@thegazette.com