New generation of wind farms arises
Technology allows more electricity at lower price
By Matt Carter, STAFF WRITER
LIVERMORE — Using technology imported from Denmark, a new wind farm in the Altamont Pass could generate more electricity at a lower price than its predecessors while killing fewer birds of prey.
But because of regulatory and economic hurdles, wind-farm operators aren't rushing to modernize all 5,200 aging wind turbines in the hills between Livermore and Tracy.
Obstacles to "repowering" — replacing wind turbines installed in the 1980s with more modern machines — include concerns about bird deaths. To claim lucrative federal tax credits, companies seeking to modernize their wind farms also must negotiate new agreements to sell their power to Pacific Gas & Electric Co.
The first wind-farm operator to move forward with a repowering project in the Altamont Pass is Altamont Power LLC, a partnership between Florida-based FPL Energy and Global Renewable Energy Partners. GREP is a subsidiary of wind-turbine manufacturer Vestas Wind Systems of Denmark.
The new Vestas V47 turbines — brought on line in December by Altamont Power at the company's Diablo Winds facility — use the latest materials, design innovations and computer automation to squeeze more electricity out of the wind.
Company officials say fewer than three dozen new wind turbines at the Diablo Winds facility on Altamont Pass Road have the potential to produce more electricity than the 169 old FloWind turbines they replace.
Although the new wind turbines are bigger than the "egg beater" FloWinds, they're also more sophisticated.
The fiberglass blades of the 31 Vestas turbines sweep through the air up to 258 feet off the ground, supported by steel towers weighing nearly 45 tons. Wind gauges on each machine measure the direction and speed of the wind, adjusting the angle of 77-foot-long blades to match conditions.
Like a bicyclist changing gears to climb a steep hill, adjusting the "pitch" of the blades helps the Vestas turbines generate electricity at a wide range of wind speeds — from 6 to 56 mph. Many older turbines only produce electricity when wind speeds top 12 to 14 mph.
Stengel said Altamont Power has invested about $25 million in the Diablo Winds project. The wind farm has an estimated 20-year life span.
To be eligible for a federal tax credit, Altamont Power was required to renegotiate its contract to sell power to PG&E.
PG&E, which had been paying 6.8 cents per kilowatt hour under a contract that was set to expire in 2016, negotiated a reduced rate of 4.3 cents per kilowatt hour for the Diablo Wind project. That rate will be allowed to rise with inflation to a maximum of 5 cents per kilowatt hour in 2016.
Altamont Power and other wind farm operators may be less willing to negotiate new contracts for older wind farms that are still generating electricity. Those wind farms rely on other models of obsolete wind turbines, and parts to repair them are more readily available.
FPL Energy operates wind farms with 220 megawatts of generating capacity — nearly half of the total in Altamont Pass — but hasn't submitted plans to modernize other facilities. (One megawatt of generating capacity is enough to supply about 1,000 homes, but most wind farms produce no more than one-third of their rated capacity).
PG&E is looking for ways to meet state mandates to obtain 20 percent of its electricity from renewable sources such as solar and wind energy by 2010. But the total generating capacity of wind farms in the Altamont Pass has been capped at 583 megawatts until wind farm operators can prove they can reduce bird deaths.
A recent study estimated that 881 to 1,300 birds of prey are killed each year in the blades of wind turbines in the Altamont and on the power lines that carry the electricity they generate.
State and federal wildlife officials, environmental groups, and the California Energy Commission hope repowering projects will curb bird deaths by reducing the total number of wind turbines in the Altamont by a factor of seven or more.
In the future, power lines will be placed underground — the Diablo Winds project eliminated eight miles of overhead power lines — and new turbines will be sighted in ways to make them less lethal to birds.
Although the Diablo Winds project was allowed to proceed under the auspices of a 1998 Environmental Impact Study, some other repowering projects will require separate studies that can take a year more.
Buena Vista LLC is working with officials in Contra Costa County on an environmental study of a proposal to repower a 37.5 megawatt wind farm on Vasco Road. The company already has begun scrapping 179 old wind turbines, which it proposes replacing with 38 modern machines.
Additional obstacles to repowering include the need to renegotiate leases with ranchers who own the land the wind farms use, and potential disputes between wind farm operators. Rows of larger wind turbines can create wakes that have the potential to reduce power generation at turbines downwind.
al obstacles to repowering include the need to renegotiate leases with ranchers who own the land the wind farms use, and potential disputes between wind farm operators. Rows of larger wind turbines can create wakes' that have the potential to reduce power generation at turbines downwind.
al obstacles to repowering include the need to renegotiate leases with ranchers who own the land the wind farms use, and potential disputes between wind farm operators. Rows of larger wind turbines can create "wakes" that have the potential to reduce power generation at turbines downwind.
