07/08/08
Wind Power to Bring Blackouts? -
Categories: State and federal mandates require power companies to get part of their power from alternative sources, like wind generation. Garland Power & Light's recent power purchase agreement does include such sources, plus GP&L operates a hydroelectric dam.
Mandates have a way of altering the market that politicians don't anticipate, such as the ethanol requirements and the effect on food prices. So it is with wind power.
Texas is the number one producer of wind power in the country. Most of the wind turbines are in West Texas. According to the Dallas Morning News, there are few transmission lines from West Texas to deliver that power to the rest of the state. New lines would run billions to construct. That cost would be passed to the consumer. However, bigger problems may be looming once the state becomes more dependent on wind generation.
Electricity demand varies through the day. In the evening it starts to drop as temperatures drop and businesses close. Through the early morning, demand is at its lowest. Then demand starts to rise as businesses re-open and thermometers start to climb, peaking in the mid-afternoon. Winds follow a reverse curve, blowing hardest before daybreak, when demand is lowest, and regularly disappearing about mid-afternoon, when demand is highest.
Other types of generation have their own idiosyncrasies. Nuclear generation is very constant, it is hard to "turn down" the reactor, and coal is similarly so, you can't flip a switch to turn it off and then back on. Natural gas is more flexible but it takes time to start these generators, too, usually hours.
Wind is rarely available when we need the generation the most. It is feeding into the grid when demand is the lowest, pushing operators to turn down other sources as much as possible.
A sudden drop in the wind, particularly drops that were not forecasted, could leave the electric grid with almost no generation on line, a blackout, and hours away from returning to regular capacity. Production managers are not saying this might happen — it's just a question of when it will happen.
A recent Dallas Morning News article on Texas wind generation looks closely at the industry and the challenges. The article carries illustrations to help explain some of the limitations and dilemmas. As you read the story, think about those situations when electricity users are depending on the wind and it just stops.
From the Dallas Morning News:
Debate flares over wind power in Texas
Power supply on hot summer day
Click graphic for larger size
08:22 AM CDT on Monday, July 7, 2008
By ELIZABETH SOUDER / The Dallas Morning News
There is such a thing as too much wind power.
Sure, wind is among the cheapest, cleanest fuels generating the power Texans increasingly demand. But as officials brag about the state's status as the No. 1 wind producer in the country, they're also debating how much is too much. Building the transmission lines to bring wind power from rural West Texas to population zones will cost billions. And even with enough transmission lines, the on-again, off-again nature of wind can leave coal and natural gas-fired power plants scrambling to fill in the gaps.
For electricity companies, predicting wind patterns is a new art.
The wind blows hardest before the sun comes up, when people aren't using much power. It tends to die down during the afternoon – especially in the summer – just when people demand more juice.
Solving each issue will cost money.
More …
