Blades Peeling Apart "Piece by Piece"

Lightning and cold weather may be culprits at nearby Allegheny Ridge Wind Project.

Trade association: ‘Blade problems are rare’

Wind-energy experts say incidents such as the splintering of two blades and cracks in five others produced at Gamesa’s Cambria Township factory are rare.
The American Wind Energy Association views the problem as a fluke, an anomaly that turned up in a time-proven industry involving a highly respected company.
“We haven’t heard of anything like this before. There have been thousands of blades installed, and this is a first,” said Christine Real-de-Azua, spokeswoman for the wind energy national trade association, based in Washington, D.C.
“Offhand, this doesn’t seem like a big issue. We haven’t heard of any other problems.”
Gamesa officials as late as Friday continued to search for a cause of the Fiberglas skin cracking on the blades, which were installed during the past several months on turbines at Allegheny Ridge Wind Farm in Portage and Washington townships.
With the troublesome blades now being removed from the towers and two already back at the Ebensburg-area plant, Gamesa officials said they will continue the investigation until the mystery is solved.
“We’re still analyzing all of the information recorded,” plant manager Alberto Gros said Friday. “We’re going back to the original material we used, the transportation.”
The problem will have no impact on employment levels at the Ebensburg-area plant, Gros said.
Investigators, including two from Spain, are looking at the manufacturing process, shipping and installation of the 143-foot-long blades on the towers, he said. Attention will be paid to all aspects of the weather, including two extreme cold spells when some of the blades were installed.
“Lightning can be a problem,” Gros told officials from Portage and Washington townships last week. “We’re trying to get as much information as we can.”
The defect is showing as cracks on the Fiberglas membrane stretched over the harder Fiberglas and plastic blade form.
“We know they are not well bonded on the edge,” Gros said.
“We’re looking at that area.”
In addition, a team of experts is at the wind farm going over blades still on the towers.
The plant has turned out 360 blades so far, a number of which were shipped to wind farms in Texas and Illinois. Gros said skin cracking has not occurred in those areas.
Five defective blades at the Portage and Washington township farm were spotted by Gamesa workers after they were in place on the towers, while the side of a sixth splintered and fell to the ground. A larger outside percentage of the skin on a seventh blade came off and also fell, officials said.
“Piece by piece, they just peel apart,” said Gros, who has been with the company for 10 years.

Full Story: Johnstown Tribune-Democrat, March 24, 2007
HT: National Wind Watch