Blades the length of almost two school buses from a wind turbine owned by Akron-Westfield School District rest on the ground while repairs are underway.

The turbine's gearbox was also brought down using a tall crane to reach the top of the 11-year-old structure's 165-foot-tall tower, which is much higher than people realize, said Dwain Wilmot, A-W technology coordinator.

"You can see Vermillion (S.D.) on a good day," Wilmot said, if you stand on the top of the wind turbine tower. "I've only seen it once or twice."

Along with removing the gearbox, the turbine's three 72-foot-long blades with a mass of about 1 ton each also had to be considered.

"It was interesting," Wilmot said. "They tied each of the blades off to the ground so they wouldn't swing."

Bringing the gearbox and blades down didn't take too long, once the wind went down enough to satisfy repair workers, Wilmot said.

"After that everything went smoothly," he said.

The repairs to the blades and known gearbox work has a price tag of just over $73,000 for the school district, but officials expect there will be additional cost, Wilmot said.

"You don't know its absolute condition until you tear it (gearbox) all apart," he said. "We're supposed to know more about the additional costs this week if they get that far."

The repairs are nothing out of the ordinary according to the manufacturer and are needed to keep the wind turbine in top shape, Wilmot said.

The district generates roughly $3,000 a month or close to $50,000 a year in revenue from energy produced by the wind turbine, he said.

"At the base of the turbine, a huge transformer sends energy out to the entire town on the local electrical grid. Pretty much everybody uses it," Wilmot explained. "The school is billed from the meter and then we generate revenue from the turbine meter."

Throughout its 11-year lifespan, the turbine has been very reliable, Wilmot said.

It still has its original blades, one of which is just now splitting open. Its gearbox is 8 years old.

"It's not unusual to have blades go bad because of stress they have to endure," Wilmot said. "Gearboxes are (also) high stress points."

The school district has known for a while the turbine's gearbox needed some work, after a bi-annual oil change, Wilmot said.

Oil samples were sent to a laboratory and analyzed. That analysis determined some of the surfaces are wearing out and the gearings flaking.

Then when Energy Maintenance Services, of Howard, S.D., was hired to do the repairs the company provided detailed photographs of the wear to the gears, Wilmot said.

"They stuck a bore scope camera into it," he said. "They did show us where the surfaces are showing some extreme wear."

When the blade damage was discovered this past summer during a bi-annual inspection, the school district decided it was time to do both repair projects, Wilmot said.

The wind turbine itself is paid off. That was done last year, two years ahead of the projected 12-year payoff, Wilmot said.

"We are having to absorb obvious maintenance work and repairs. That's just a normal part of owning and operating a wind turbine," he said. "Eventually everything wears out."

In addition to bringing the wind turbine back into top working order, the repair work has also become a learning tool for some A-W students.

High school math teacher Mike Baker brought his math analysis and pre-calculus juniors and seniors to the site of the wind turbine when it was dismantled for repairs earlier this month.

The students used math problems to answer questions they came up with.

For example they looked at dollars and cents and asked if it is worth it to the school to make the $70,000 in repairs.

Students learned revenue from the wind turbine will pay back that cost in in 1 1/2 year's time, Baker said.

Baker also plans to take his pre-calculus students back to the turbine site because they want to measure variables and determine if a projectile end of a blade would hit Superintendent Tony Ryan's house.

When Baker asked his pre-calculus students Tuesday if the initial trip to see the wind turbine was worth it, he received loud favorable confirmations.

And then he asked them why.

"Because it's real-life application," Senior Grant DeRocher said.