Wind stream

Workers are busy at the site of tower eight of the O’Brien Wind Energy Project just northeast of Sanborn. The project counts a total of 104 turbines, which combined can produce 250 megawatts of energy.  Photo by Rylan Howe

REGIONAL—A wind farm under construction is helping renew O’Brien County’s role as the wind energy production capital of Iowa.

Crews from Mortenson Construction of Minneapolis will have erected 25 of the 104 turbines that will make up the O’Brien Wind Energy Project. The wind farm will produce 250-megawatts of energy in northern O’Brien County once it is completed.

“By the end of November we should be done,” said Scott Cobb, a wind project manager for MidAmerican Energy, which owns the development.

This project is the second MidAmerican Energy-owned wind farm in O’Brien County.

The first wind farm was the recently completed 214-turbine Highland Wind Energy Project, located throughout southern portions of the county. It can produce 502 megawatts of power.

Combined, both wind farms will be capable of producing 752 megawatts of wind power, more generation than any other county in Iowa and among the highest nationally.

MidAmerican Energy’s latest wind investment in the county already has changed the skyline along the north side of Highway 18 west of Sanborn. A number of the 263-foot tall wind turbines are visible from the thoroughfare. Other portions of the project will be east, northeast and southeast of Sanborn.

Ahead of schedule

Construction on the new wind farm is about a week ahead of schedule, something Cobb contributed to ideal weather this summer and the construction crew’s familiarity with the process.

“It’s the same crew as the last build, this layout construction yard was here already, it’s the same turbine, same tooling, same contractor,” he said.

Another factor that has helped things go smoothly for MidAmerican Energy is support from area landowners. Cobb noted the success of the Highland Wind Energy Project made northern O’Brien County landowners more receptive to hosting wind turbines.

“They know what it looks like when it gets finished and how it gets restored and they know the repairs happen in a timely manner for drain tiles and things like that,” he said. “Crop damage gets taken care of and reimbursed.”

Like its predecessor, the O’Brien Wind Energy Project is expected to generate large tax revenues for O’Brien County in addition to electricity.

Seven fiscal years after the project is completed — theoretically in fiscal year 2017-18 — O’Brien County would receive 30 percent of each device’s assessed value, or about $18,000 per turbine. A little more than half of those tax revenues go to the public school systems in areas where turbines are present.

Participating landowners also are expected to benefit financially from the turbines.

Cobb did not provide specifics, but said each individual negotiation is line with one another and is based on the numbers of turbines on a property, how many megawatts the turbine produces, per circuit foot of cable buried on the property and for allowing access roads to the devices on their land.

No more planned

Earlier this year, MidAmerican announced Wind XI, its plans to invest $3.6 billion into building more wind farms in Iowa. Called the largest economic development deal in the state’s history, landowner payments on that project are expected to be about $18 million annually.

Although they have had great participation from O’Brien County landowners in the past, Cobb said the county is not being considered for the Wind XI project at this time.

“We haven’t looked at anything else in O’Brien County,” he said.

Another developer, Apex Clean Energy of Virginia, expressed interest in possibly bringing another wind farm to O’Brien County in January; however, that project, Upland Prairie Wind, appears to be taking place only in Clay and Dickinson counties.

While no additional wind developments are slated for O’Brien County at this time, the Highland and O’Brien projects will remain viable for at least the next four decades.

Both wind farms have a 40-year lifespan, but there is a decommissioning agreement in place with the county and landowners once that time arrives.

“We build them and we tell everybody 40 years is what we want to have on these,” Cobb said.

“The contract we have with the landowner is that if we don’t do anything else and we decide we are not going to use this park anymore, we are obligated to remove everything.”


According Scott Cobb, a wind project manager for MidAmerican Energy:

  • It takes about three weeks to build a single wind turbine.
  • Each turbine is 263 feet tall.
  • Rotator blades are 173 feet long and rotate six to 16 revolutions per minute.
  • The foundation for single wind turbine requires 531 cubic yards of concrete and 96,000 pounds of reinforcing steel.
  • Energy generation begins when wind speeds reach 7 mph and maximum generation occurs at 25 mph.