The wind hasn’t provided much relief to Texans during the recent stretch of a 100-plus degree days, but it has helped to keep air-conditioners humming.
Texas’ wind turbines – particularly those along the Gulf coast — have come through for the state’s electric grid more than expected during the hot afternoon hours when demand has been its highest.
Wind only accounts for about 11 percent of the state’s total power capacity, and last year only 8 percent of the power produced in Texas came from wind turbines.
But during last week’s daily power crisis, officials with the Electric Reliability Council of Texas, which manages the state’s main high voltage power grid, repeatedly touted wind power’s contributions during peak demand.
Typically ERCOT only expects about 800 megawatts of power to come from the 9,500 megawatts of wind turbines installed around the state.
But wind’s contribution ranged from 1,300 megawatts to 2,400 megawatts during peak demand — including 2,000 MW last Wednesday, when the state set a new power demand record at 68,294 MW.
It’s a big improvement from last summer, when only 650 MW of wind power was humming during the peak hours of Aug. 23, when Texas hit its 2010 record of 65,776 MW.
“The wind gods have been very very good to us this summer,” said Ted Hofbauer, director of asset management for Pattern Energy, which owns and operates the 283 megawatt Gulf Wind project south of Kingsville in Kenedy County.
Typically a wind power project produces 30 percent to 40 percent of its rated capacity on a good day – meaning a wind farm with 100 MW of wind power capacity would generate 30 to 40 MW – said to Hofbauer.
“We’ve been close to or at 100 percent many times during the past week during the afternoon peak,” Hofbauer said.
Most of Texas’ wind farms, located in West Texas, reach their peak output in the evening, when the winds blow hardest. They do little for the state’s needs during the hottest afternoon hours and are so far removed from the areas of heaviest demand that they often have little to no impact.
But the growing number of wind projects along Texas’ coast has helped boost wind’s contribution during peak summer hours since coastal winds tend to pickup in the afternoons.
As the land heats up during the day the air mass above it rises, pulling in the cooler air over the water and creating steady offshore winds.
Spanish utility Iberdrola’s 404 megawatt Penascal Wind Farm on the Texas Coast just south of Corpus Christi was running at the upper range of its capacity, said spokesman Paul Copleman.
E.ON’s 380 megawatt Papalote Creek project north of Corpus Christi was running at 80 percent to 90 percent of its capacity for much of the past two weeks.
“We’ve seen good wind this summer, even in West Texas,” said E.ON spokesman Matt Tulis.
Wind power has plenty of critics, however.
Wind energy receives a federal production tax credit of $22 per megawatt-hour or 2.2 cents per kilowatt-hour.
Wind power projects have also been on the receiving end of other federal funds. Iberdrola’s Penascal project received a total of $222.8 million in federal stimulus funding.
Coast wind farms also have drawn fire from environmentalists who are concerned their location along key migratory bird routes could kill thousands of birds.
The Penascal and Gulf Wind projects both use a portable radar system to monitor for flocks of birds in the area, and have promised to shut down turbines if necessary to protect birds, but neither project has had to do that yet, the companies say.
“We’ve had average avian mortality,” Hofbauer said, meaning the numbers of dead birds found around the turbines has been similar to what other wind facilities around the country report. “We’ve found they tend to be flying well above our turbines.”
Robert Bryce, an Austin-based author who has been outspoken in his criticism of wind power, says wind power doesn’t do enough to contribute to the state’s power needs.
He notes that wind’s variability and the poor peak-day output from the West Texas wind farms means ERCOT only counts 8.7 percent of the installed wind capability toward its total reserves.
“Yes, the coastal turbines are doing better than the inland turbines, but coastal turbines face much more resistance from local residents than ones that are located near Big Spring or Sweetwater,” Bryce said, as residents don’t like having the 450 foot-high towers blocking their coastal views.
Texans are also paying about $4 more per month on their electric bills to finance the construction of hundreds of miles of high voltage transmission lines to bring wind power from rural West Texas to more populous parts of the state where it’s needed.
Meanwhile, the turbines keep coming.
Just this week Duke Energy and San Antonio municipal utility CPS Energy announced a deal to buy 200 megawatts of wind power from a planned wind farm to be located 20 miles from the coast in Willacy County.
The American Wind Energy Association says there were 7,354 MW of new wind capacity under construction as of the end of June,