DANVILLE — Extreme weather is being blamed after an investigation into why two blades broke off a California Ridge Wind Farm turbine near Oakwood Junior High School.
According to wind farm owner Invenergy, about 9 p.m. Nov. 20, a blade on turbine No. 134 in the California Ridge facility broke off and fell to the ground near the base of the turbine, which sits northwest of Oakwood Junior High and near the intersection of county roads 2150 N and 900 E north of Oakwood.
"We believe that as this blade fell, it hit a second blade on the same turbine, causing that second blade also to break off and fall to the ground near the base," Invenergy said in its statement.
Daphne Turner was home with her family in their rural home where they can see turbine No. 134 from the back of their property. Turner said she heard a loud noise and felt the house shake for a few seconds that night. Thinking someone was on their property, Turner went outside to check, saw nothing, and didn't know until morning that what she had heard was the turbine blades breaking. Turner said it makes sense that the severe weather just days before may have damaged the integrity of the blades.
According to Alissa Krinsky with Invenergy, the turbines monitor wind and turn off when they detect high speeds.
Turner, who does not lease property to Invenergy, said she wishes the company would inspect all the blades after such severe weather before turning them on again, and she also would like to see an incident report detailing where the broken pieces landed in comparison to nearby properties. Turner said she did get a call from the company answering some of her questions about the incident.
Invenergy officials said the turbine, as designed, automatically stopped after the blade break. No one was injured, and Invenergy has been working with officials from General Electric, the turbine's manufacturer, to determine the cause of the break. The turbine remains non-operational with its lone remaining blade intact.
Lindsay Theile with GE said early indications of the investigation into the recent blade failure point to extreme weather.
The break occurred three days after severe storms ripped through Illinois, including a tornado that devastated Gifford, about 25 miles northwest of the broken blade. The 134-turbine California Ridge project stretches from far eastern Champaign County, where there are 30 turbines, into western Vermilion County, where there are 104 turbines. The broken turbine is at the most eastern edge of the wind farm in Vermilion.
It's the second turbine in California Ridge to experience a broken blade, each of which are about 159 feet long, and the third turbine in East Central Illinois to experience a blade failure. A blade broke off another California Ridge turbine in November 2012.
Invenergy's Krinsky said that break was determined to be a result of a manufacturing issue. The California Ridge project uses 1.6-megawatt turbines manufactured by GE — the same as the ones in the Settlers Trail Wind Farm near Sheldon, where a blade broke in June 2012. That wind farm is operated by Chicago-based E.On Climate & Renewables, and last March, GE issued a statement saying that an isolated manufacturing issue was also the cause of the first break in the Invenergy project and the one in the Settler's Trail project.
GE said then that the company had reviewed the turbine fleets at both projects to ensure their reliability and performance and addressed the manufacturing issue to prevent it from happening in the future. But those aren't the only blade breaks GE has experienced.
Breaks have happened recently in other wind projects in the U.S., and GE has been investigating each of them to determine the cause.
Three days prior to the most recent break in Vermilion County, a blade broke from the same kind of GE wind turbine at an Invenergy-owned wind farm in New York. And in Michigan, blades broke on the same type of turbines in different DTE Energy wind farms in March and on Nov. 7.