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Tuesday, July 3, 2012 - Page updated at 07:30 p.m.
Power half-restored after windstorms in East
By JOHN SCHWARTZ
The New York Times
About half of the 4.3 million customers in 10 states and the District of Columbia whose power was knocked out over the weekend by storms, which killed 22 people, have their power back, according to the Edison Electric Institute.
That left nearly 2 million customers still without lights, refrigeration, air conditioning or even electric fans as temperatures approached or exceeded 100 degrees from Atlanta to Baltimore.
Dominion Virginia Power predicted some of its customers will not have service back until next weekend.
Ken Barker, a vice president for customers services, said so many neighborhoods sustained "catastrophic damage," with downed poles and wires swirled like spaghetti on the ground, that "basically, we're just hauling it off and rebuilding our poles and wires."
The industry says it uses a well-established process in bringing power back to the largest number of people in the shortest time. That process begins with the power plants, then utilities check their high-voltage transmission lines and then substations, which send power out on local distribution lines. Workers restore power first to hospitals, police stations, fire stations, water-treatment plants and other essential facilities. Next come lines that will bring power back to the largest number of customers — downed lines for neighborhoods and businesses. Only then do they move on to smaller clusters of houses and individual homes.
After the great blackout of August 2003, in which a handful of "tree contacts" led to a cascade of failures of the high-voltage power grid across eight states in the Northeast and Midwest, as well as parts of Canada, new regulations were put in place for trimming trees and training power operators. Such measures might well have prevented failures over the weekend from spreading even more widely, said Clark W. Gellings at the Electric Power Research Institute.
"You can't stop outages," he said. But, he added, the industry is working to make power distribution more resilient, with better monitoring of the grid to spot problems.
The industry is also developing tools to help repair crews do their work, including a drone, being tested in New Mexico, that could help workers learn which roads are and aren't passable.
All such tools and techniques will be needed; the problem of storms is likely to grow worse. Harold Brooks, a research meteorologist at the National Oceanic and Atmospheric Administration's national severe-storms laboratory, said models of climate change suggest that over the next 100 years, a warming Earth will provide more energy for storms.
One seemingly obvious way to avoid downed lines is to bury them, a technique called undergrounding. But a 2009 study prepared for the Edison Institute found that while a quarter of new lines are buried, the costs of converting overhead lines would be five to 10 times more than overhead construction — $80,000 per mile for rural construction to $2,130,000 per mile for urban construction.
And though burying lines protects them from falling branches, the lines are not immune to water intrusion. Gellings said the best defense against storm-related power failures is the simplest: "trimming trees."
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