Wind harvesting continues close to projections
By Jolene Farley
A venture into the wind energy market by two local investment groups has gone well so far, according to Minwind I President Mark Willers.
The first wind generator, three miles southeast of Beaver Creek or seven miles southwest of Luverne, started operation on Wednesday, Oct. 8. The last of four turbines, all owned by the Minwind groups, was running by Thursday, Oct. 17.
Despite a partial month in October and some operational procedure issues the first few days of November, the turbines generated enough energy to come within 5.5 percent of projected revenue.
"We thought this was extremely good, considering that we had only been up and running for six and a half weeks," wrote Willers in a letter to stockholders.
NEG Micon of Denmark crews, the manufacturers of the equipment, worked out some bugs along the way.
Technical difficulties weren’t totally unexpected, according to Willers.
"Every time you have a several million dollar project, you have a few things to work through," Willers said.
One generator required new hydraulics, covered under warranty. Routine software updates from NEG Micon, provided every six months and part of the contract, were installed on all the generators.
"The first few weeks, you kind of wonder," said Willers. "But the last four or five weeks things have been going very well."
The first annual Minwind investor meeting is planned for Monday, Feb. 3. Future projects will be discussed, and accountant Dan Heard, Rock Rapids, will advise investors on tax credits and their effect on shares.
John Dunlap, President of American Wind Energy Association, may speak on future growth in wind generation and cost analysis of other forms of energy production.
The Minwind groups, both Limited Liability Corporations, each spent $1.6 million on the project, which will be paid off in 10 years.
The groups are unique because they are the first in the state to own turbines. Most are owned by power companies, which then lease land from individuals.
Visit at your own risk
Visitors to the local wind turbines should be cautious, according to Willers. Light rain, wet snow or fog, can cause ice buildup on turbine blades.
In October ice chunks more than two inches thick and anywhere from 8 to 15 feet long formed on generators by Chandler.
A chunk fell on a full size service van parked directly below the blades, caving in the top of the vehicle.
Luckily, the workers weren’t in the vehicle but were inside the tower at the time of the accident.
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People ask, "When do the generators run and why do they run at different speeds?"
Sometimes one or two generators coast at low wind speeds and the others aren’t moving.
When a generator isn’t moving, the generator’s computer has applied the brakes (at slower than 3-mph wind speed) to keep the turbine in place so coasting doesn’t cause additional wear on the transmission.
Sometimes one turns slowly while the others turn faster, (between 3- and 5 1/2-mph wind speeds) the generator is coasting to build momentum.
At 5 1/2-mph wind speeds, the computer shifts the small generator into operation, and a small amount of electricity is made. The blades are moving at 14.4 revolutions per minute.
When the wind blows at about 6.8 mph, with the blades moving at 22.2 rpms, the computer starts the large generator and the turbines start producing substantially more electricity.
If the wind is about 6.8 miles per hour, the computers of any given wind generator may be running at either low or high speed.
Therefore, some turbines could be running at 14.2 rpms and some at 22.2 rpms.
Once running at 22.2 rpms, the generators continue running at this speed up to 68-mph wind speed.
The blades don’t move faster, the generator shifts gears automatically, increasing production.
In the evening, when the wind dies down, the blades may come to a complete stop for 10 to 12 minutes, then begin turning again at 14.4 rpms.
When the wind picks up, the computer can shift the transmission up automatically, but when the wind speed slows down, the generator must come to a complete stop.
The computer then shifts the transmission off for a period of time and starts it back up safely.