Old Wind Farm Has a Secret
by Tina Casey
The new turbines, provided by Vestas, will have a far larger capacity rating
than late 20th century wind turbine technology.
New wind farm projects tend to get a lot of attention, but older arrays are due for their 15 minutes of fame in the renewable energy revolution, too. That's because on top of those aged wind turbine towers sits a signifianct opportunity to squeeze many more megawatts out of the same site, as demonstrated by PacifiCorp's new wind farm repowering project in Wyoming.
The Portland-based energy company PacifiCorp (a subsidiary of Berkshire Hathaway) has been making preparations to upgrade its older wind resources for a while now. Last week it completed one of the last big pieces of the wind puzzle by acquiring full ownership of Foote Creek I, a 41.4-megawatt wind farm located, somewhat ironically, in a Wyoming county that goes by the name of Carbon.
First commissioned back in 1999 as a demonstration project after years of planning, Foote Creek belongs to an early generation of utility-scale wind projects in the US. Its 68 turbine towers still sport their original 600-kilowatt Mitsubishi generators.
Though the turbines are aging, PacifiCorp is not shy about crediting Foote Creek with sparking the company's early-adopter, vanguard status as a wind energy investor over the past 20 years:
"The success of the facility and ongoing technological advancements led PacifiCorp to invest billions of dollars in low-cost wind energy, create associated tax revenue benefits and new wind energy jobs in rural communities in Wyoming, Washington, and Oregon. PacifiCorp is today the largest regulated utility owner of wind assets in the West."If all goes according to plan with the repowering project, the Foote Creek upgrade could also motivate other wind asset owners to go ahead and take advantage of improvements in turbine technology.
Pacificorp is looking at an increase of 60% in overall energy output for the facility while maintaining its peak output capability, even though the number of wind turbine towers will plummet from 68 to just 13.
The new turbines, provided by Vestas, will have a far larger capacity rating than late 20th century wind turbine technology. Today's longer turbine blades are the most visible element in the efficiency improvement. Somewhat less visible are improvements in gearbox controls and energy management systems over the past 20 years.
Wind Farms Vs. Coal Mines: Behind The Megawatts
PacfiCorp also takes note of some extra benefits associated with keeping the site active while trimming the number of turbine towers.
According to the company, the new equipment will help reduce operating costs while extending the lifespan of the array for another 20 years or more, with the savings (thanks, federal production tax credit!) passed along to ratepayers.
Though each of the new turbines is larger than the original models, the total footprint is not expected to exceed the existing footprint of 1% of the property, enabling use of the land for grazing and other agricultural pursuits.
The ability to extend the useful life of Foote Creek I is quite a contrast with the ongoing impacts of abandoned coal sites in Carbon County and elsewhere, including surface impacts from subsidence and underground fires.
As recently pointed out by High Country News, the problem of coal mine abandonment could leave the entire state in financial disarray. The warning signs include Cloud Peak filing for bankruptcy last spring and the more recent bankruptcy of another leading Wyoming coal producer, Blackjewel:
"With mines likely to close, Wyoming is entering a new and untested paradigm for coal -- reclamation without production. Typically, mines clean up their mess as they go; if they don't, then the state can shut down operations until they do. But once a company goes broke and the mine shuts down, the only funds for cleanup are reclamation bonds, which critics say are inadequate in Wyoming."More Wind For Wyoming (& Solar, Too)
With coal on the way out, Wyoming could use a few more of those renewable energy projects to fill in the gaps and restore the local tax base.
The state currently ranks #17 for installed wind capacity, a disappointing figure considering that it sits smack in the middle of some of the nation's best-quality wind resources. However, it is set to add another 3,753 megawatts to its current stockpile of 1,488 megawatts.
The state could use more help on the solar side, where its current ranking is down at the #36 mark for installed solar capacity.
That could change sooner rather than later. Though the state is far from the solar-rich southwest, evidence is beginning to pile up that cooler weather helps solar panels function more efficiently.
Just last summer, regulators greenlighted construction of the Sweetwater Solar facility, the very first utility-scale array in the Wyoming. That seems to have sparked a rush of interest from other developers.
PacifiCorp has a hand in that trend, too. Sweetwater was developed by a subsidiary of Hanwha, with an agreement to purchase the electricity by PacifiCorp subsidiary Rocky MountainPower.
CleanTechnica is reaching out to PacifiCorp for more insights on renewable energy development in Wyoming, so stay tuned.
BPA Signs Wind Power Deal by Associated Press, Capital Press, 12/21/1
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