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What’s up with wind towers?

Saratoga – Preliminary work has begun on the Saratoga Wind Farm that will have 33 wind towers when finished. They are being built by Madison Gas & Electric and will produce 66-megawatts of energy. It is expected to become operational in early 2019.

MG&E built Rosiere Wind Farm in 1999 in Kewaunee County, Wis. It contains 17 wind turbines and stands 290 feet tall. Top of Iowa Wind Farm in Worth County, Iowa was built in 2008 and has 18 turbines. It stands 400 feet tall. Saratoga Wind Farm turbines will be 499 feet tall.

Roads: Before any work could begin, the county has to get involved. Howard County Engineer Nick Rissman explained the construction company had to get permission from the county to change the footprint of the roads. “Anyone wanting to do something in the road right-of-way needs to get a permit from the county,” he said.

Also, the county has to analyze every structure the heavy equipment will be traveling over, such as roads, culverts and bridges. “There was one bridge we said they couldn’t use unless they replace it. They opted not to use that route. And, if they damage any road, they have to pay to fix it.”

For the heavy equipment going in and out of the tower sites, the access roads were strengthened.

To reinforce the infrastructure, a powder is knifed into the ground to make it hard. The process is called ground stabilization.
Saratoga Wind Farm signed a road use agreement for all the work being done.

All the driveways and intersections are being widened to allow for the extra-long semis to get the precast tower sections to the building site. Afterward, the extra rock will be removed to be used as fill at the various tower sites.

Concrete: Dean Mackenburg of Croell Redi-Mix at Cresco and Lime Springs have been supplying the concrete for the base.

He said the first step is to put down a mud mat or base which consists of 40 yards of concrete. That ages for a while as the rebar, which is 1.5 inches thick at the maximum, is installed. Each base holds 75,000 pounds of rebar.

Each “hole” needs to be inspected before the concrete for the base can be poured.

For the past 3-4 weeks, the redi-mix plant has been pouring 350 yards as a base for each unit. Then a pedestal of 40 yards is installed. Each load holds 10 yards, which means it takes 43 loads to finish a hole.

It takes at least a month before the concrete is hard enough to withstand the weight of the towers themselves.

An interesting sidenote about the concrete for this project is it is required to be below 87° Fahrenheit for the base and 81° for the pedestal. “If it is over that,” Mackenburg explained, “there is a formula we follow to add ice to cool it down. It takes about 20 pounds per yard.” So far, they have not had to go the ice route, but they do run water over the rocks to keep them cool.

Turbines: Dan Clausen of MG&E said the turbine parts will start arriving around Aug. 27. “They will come by train from factories in Colorado and be unloaded at Manly. Then they will get loaded on semis.”

In addition, a large crane began arriving last week, which needs to be constructed on-site. A maintenance building will be put in at Davis Corners. Six employees will work full-time out of the office.

“We plan on being done by the end of the year,” Clausen stated. The energy produced by the turbines will go into the midwest grid.