FREDERICTON — A $200-million wind farm in northern New Brunswick is frozen solid, cutting off a potential supply of renewable energy for NB Power. The 25-kilometre stretch of wind turbines, located 70 kilometres northwest of Bathurst, N.B. has been completely shutdown for several weeks due to heavy ice covering the blades.
GDF SUEZ Energy, the company that owns and operates the site, is working to return the windmills to working order, a spokeswoman says. “We can’t control the weather,” Julie Vitek said in an interview from company headquarters in Houston, Texas. “We’re looking to see if we can cope with it more effectively, through the testing of a couple of techniques.”
She says the conditions in northern New Brunswick have wreaked havoc on the wind farm this winter.
“For us, cold and dry weather is good and that’s what’s typical in the region. Cold and wet weather can be a problem without any warmer days to prompt thawing, which has been the case this year.
“This weather pattern has been particularly challenging.”
Wintery conditions also temporarily shutdown the site last winter, just months after its completion. Some or all of the turbines were offline for several days, with “particularly severe icing” blamed.
The accumulated ice alters the aerodynamics of the blades, rendering them ineffective as airfoils. The added weight further immobilizes the structures.
Ms. Vitek says workers are trying to find a way to prevent ice buildup from occurring again in the future. The shutdown has not had any effect on employment at the site, which provides 12 permanent jobs.
In February 2008, Suez was awarded a contract to build a 33-turbine wind farm at Caribou Mountain. NB Power signed a 20-year power purchase agreement for its 99 megawatts of power capacity, which went online in November 2009.
At the time, the project was praised for bringing NB Power to its goal of having 400 megawatts of wind power capacity by 2010. The facility has enough capacity to power about 19,000 homes.
Melissa Morton, a spokeswoman for the utility, says the contract isn’t based on power delivered during a specific period, but rather on an annual basis.
“Although there may be periods when production is down from what would be expected, there are also periods when production is above what would be expected,” she says.
“We only pay for the energy that actually goes on our transmission system.”
But with energy market prices changing constantly, she says there’s no way to know if NB Power is paying more or less for replacement power.
“It can be more expensive. It can also be cheaper,” she says, but fluctuations in production at other sites can make up the difference.
“Our hopes is that it will balance out over the 12-month period and, historically, that has been the case.”
Despite running into problems in consecutive winters, Ms. Morton says NB Power doesn’t have concerns about the reliability of the supply from the Caribou Mountain site.
Suez’s website states its wind farms on average produce about 35% of their capacity on an annual basis, accounting for daily and seasonal fluctuations in wind patterns.
David Coon, executive director of the Conservation Council of New Brunswick, says winter tends to bring higher winds to the province, which would push wind farms to produce more power.
He says the problems at Caribou Mountain are confusing, as other projects in cold climates haven’t had similar ice issues.
“I don’t know why, because there’s a lot more wind (farms) to the north of us in Quebec, so I don’t know why in particular they’re having trouble,” he says.
NB Power also has contracts to buy power from other wind facilities in the region.
A TransAlta-owned wind farm, located south of Moncton, consists of 32 turbines. An additional 18 turbines are being constructed at the site, which will make it the largest wind farm in Atlantic Canada.
NB Power also has power-purchase agreements with the Acciona wind project in Lamèque and another Suez farm on Prince Edward Island.
Suez operates a second wind farm on the Island, as well as owning facilities in Central and South America and across Europe.