5/8/10 TRIPLE FEATURE: Guess what? You're moving. And you're one of the lucky ones: Wisconsin homes to be bought out by wind developer AND The usual story about yet another 'unusual' turbine blade fail AND Cause of 'unusual' wind turbine collapse still unknown many months later, collapse zone established
Turbine Blade Damage 'Unusual'
SOURCE: Daily Chronicle, www.daily-chronicle.com
May 7, 2010
By Dana Herra
SHABBONA TOWNSHIP – Officials at NextEra Energy Resources aren’t sure what caused one of the three blades on a wind turbine south of the village of Shabbona to fail Friday morning. The 131-foot-long blade hung from the top of the turbine Friday, apparently bent at the base and split along its length.
That type of failure is unusual, NextEra spokesman Steve Stengel said.
“Our inspection at this point has just been visual, so at this point we don’t know what caused that,” Stengel said Friday afternoon. “Based on just visual inspection, it’s very unusual to have a blade fail and look like that.”
Stengel said the blade failed about 7:30 a.m. Friday. No one was injured and nothing besides the blade was damaged, he said. The turbine has been shut down.
The access road leading from Houghtby Road to that section of the 145-tower commercial wind farm was blocked off with orange cones and traffic barricades Friday. Stengel said NextEra is in the process of getting a replacement blade and arranging for a crane to repair the turbine so it can go back online after the cause of the failure has been determined.
Several vehicles pulled to the side of Houghtby Road while their occupants looked at the broken turbine Friday. One of those looking was Mel Hass, a member of a citizens group that filed a lawsuit last year opposing the wind farm.
Hass said he came to look at the turbine after getting a call that it had failed, and he had wondered if it was somehow damaged in a Thursday night thunderstorm.
Windmill Down; Fences Up
May 8, 2010
Safety Measures Implemented to Keep Public out of ‘Collapse Zone’
By Martha E. Conway
(Fenner) Enel Energy officials announced in March that heightened safety measures would be taken in light of the collapse of a windmill in the Fenner Wind Farm on Buyea Road Dec. 27.
“When the incident occurred, we fenced it off and set up security,” said Hank Sennott, director of corporate affairs and communications for Enel North America, Inc., out of Andover, Mass.
Now Enel is fencing off every turbine, Sennott said. He said with all the snow that stuck around this winter, it was difficult for anyone to get to the turbines, but with it gone, the company is erecting snow fencing to demarcate the “safety zone.”
“We are exercising an abundance of caution,” Sennott said. “The public has gotten use to having pretty liberal access to these turbines. We also needed to stake out the space before farmers begin working their fields.”
One of the things that made leasing so attractive to farmers was that they could work the land virtually up to the base of the windmill towers. Now Sennott says compensatory agreements will be made for the loss of use of the cropland unavailable inside the 300-foot radius – about the height of each windmill – staked out around each turbine.
The decision was made after concrete core samples from the foundations preliminarily showed inconsistent aging and degradation.
“Some of the samples looked like they were poured yesterday,” Sennott said. “Others… Didn’t.”
According to Sennott the samples of five or six foundations led to the decision to test all 19 in the project. He said the company is in the home stretch of collecting data and a report is expected soon.
Surveyors also are working the site to make sure towers are not moving, Sennott said.
“The last thing we want to do is have something happen,” Sennott said, adding that also is the motivation behind not hurrying to restart the turbines.
Sennott said he doesn’t know how much revenue is being lost each day the turbines don’t turn; he said he hopes the company can pull back the fences quickly and Enel’s expectation is that the turbines will be up and running by the fall.
“I don’t know of any turbine foundation failures, but we were the first, so there is nothing to go back and research,” Sennott said. “This project was the larges built east of the Mississippi when we constructed it 10 years ago. There’s no history for us to look at.”
Sennott said how much location may play into the problem is still a big unknown.
“That’s why we’re being overly cautious,” Sennott said. “Maybe we’ll look back and think it was excessive, but we would rather go overboard on the side of safety. We’ve never had any incidents, and we’ve never had anything like this ever happen.”
The top windmill engineering firm in the world is working on the investigation and report, Sennott said, and subcontractors who helped construct the project also are assisting.
“It’s been a real collective effort to try and sort this out,” Sennott said. “Everyone’s stepped up to the plate.”
Sennott said the community pride in the wind farm has been unparalleled.
“We can’t go anywhere without people tapping us on the shoulder, asking us when they are going to be started again,” Sennott said. “It shows that people are interested and care. There is real community pride in this project. Everybody’s been great. You don’t know how it feels to visit the Fenner website and see our turbines there. That really says it all.”
The Fenner Windpower Project consists of 20 wind turbines, each with a capacity of 1.5 megawatts for a total installed capacity of 30 megawatts. Each wind turbine generator consists of a concrete foundation, a 213-foot-tall tubular steel tower, a 231-foot diameter, three-bladed rotor connected to a gearbox and generator, and an electrical control center to automatically operate the system.
The towers are 13.5 feet in diameter at the base and 8.5 feet at the top. The total height of each tower with blade extended is 328 feet; each blade is 113 feet long.
Each turbine weighs 380,000 pounds; the concrete foundation for each tower weighs more than 610,000 pounds. Access to the top of the tower is made by use of a vertical ladder located inside each tower.
The project is located in the town of Fenner, about 20 miles east of Syracuse in Madison County. The project encompasses about 2,000 acres of leased land running from the intersection of Mile Strip and Bellinger Roads in the North to the intersection of Buyea and East Roads in the south.
Two additional wind turbines and the electrical substation are located south of the intersection of Peterboro and Rouses roads, east of the main project site. Electricity produced by the windmills is transmitted to the National Grid power grid.
Construction began in June 2001 and was completed in November of that year.