10/9/2008 10:00:00 AM Goal is to have Bloomfield wind farm operating by end of year
NPPD PhotoIt takes a big crane to lift up the pieces of the massive 262-foot wind turbines that are being constructed near Bloomfield as part of the Elkhorn Ridge wind farm.
BLOOMFIELD - Jack Kosman likes the challenges of his job as project construction manager for the wind farm north of here known as Elkhorn Ridge.
"Each day is different and something new happens," Kosman said. "It makes the days pass quickly."
Kosman's home is Cedar Rapids, Iowa, and he is looking forward to spending some time there in December when the Elkhorn Ridge project is completed.
By Dec. 31, all 37 wind turbines will be operating and generating power.
As of this week, 20 turbines are completely finished. All of the 262-foot towers have been under construction at some level since the work began, Kosman said.
His average daily crew of 90 to 100 men works 12-hour days, six days a week. Depending on what phase the construction is in, the crew may even be larger than 100.
Kosman said this is his first experience with this particular turbine design. Although the turbines may look all the same to laymen, there actually are many different designs.
While some of the turbines are still being assembled, some of the first erected are being tested to see if they are operating properly - for example, to see whether they are electronically communicating with each other.
Proper weather conditions are needed for making sure the turbines and their 145-foot blades spin correctly in order to generate electricity. In other words, wind is needed for the tests.
The recent warm, calm fall weather allowed for progress overall on construction but didn't lend itself to testing blades, Kosman said.
"We don't want a calm day obviously," Kosman said. "The minimum wind speed needed to turn the blades is 7 mph."
The wind speed for the best operating conditions for the blades is 15-18 mph. If the winds increase to 48-50 mph, an automatic shutoff inside the turbine shuts the machine down.
The towers in Knox County are the biggest land-based machines being used today. When the blades are vertical, the entire height of the structure is 410 feet.
The Bloomfield wind farm covers four to five miles and is aligned with a Nebraska Public Power District transmission line. When the electricity is running to all 37 towers, they light up the skyline.
All towers will have synchronized lights so they will flash on and off as one.
The concrete base contains 500 yards of cement. The landowner-farmer is able to farm within 16 feet of the base of the tower. The 16-foot strip around the tower is graveled and used as an access road for employees who need to check the tower operation.
Since the towers are computerized, just a click of a keyboard key allows project engineers and technicians the opportunity to check operations from a distance or as close as the "nacelle" inside the turbine tower if needed.
The "nacelle" is what the workers call the inside control room and it is used to check the day-to-day operations.
When the turbines begin generating electricity this December, the Nebraska Public Power District - which has contracted with Elkhorn Ridge to buy its electricity - will be ready to incorporate the juice directly into the current grid of electricity owned and sold by NPPD, said Mark Becker of Columbus, the utility's media relations specialist.
NPPD, which has already constructed a substation north of Bloomfield, also is working with a separate wind project in Knox County known as the Crofton Hills Wind Farm.
NPPD has a goal to be using 500 megawatts of wind generated electricity by the year 2020, Becker said. Its first wind farm near Ainsworth produces 60 megawatts while the Bloomfield and Crofton farms will produce a combined 122 megawatts.
"We are always looking for opportunities to purchase and provide electricity to our customers while working to keep the rates as low as possible," Becker said.
