Should the Northeast Bury its Power Lines?

Monday, November 19th, 2012

Hurricane Sandy left 6 million people without power. Irene left 7.4 million homes without power. So, should the Northeast bury its power lines?

Fallen trees, snow, and ice are major causes of power outages, so putting electrical infrastructure underground means customers have fewer service interruptions. According to data from the Edison Electric Institute (EEI), between 2004 and 2008, customers with aboveground electrical infrastructure experienced 1.3 power outages per year, on average. In contrast, customers with underground electric networks experience an average of 0.1 outages per year. In addition, underground lines seem to cause fewer injuries than overhead lines.

Yet 80 percent of our power lines are located aboveground, and the main reason for that is cost. “It’s tremendously expensive to bury power lines,” says Mark Garvin, president of the Tree Care Industry Association, whose members are often hired to clean up fallen trees after a big storm.

It can be somewhat affordable to use underground power cables when you’re starting from scratch, he says; developers building new housing tracts can install buried power cables alongside fiberoptics lines and water systems.

But retrofitting is much pricier. “If you’re talking about a built environment where the lines are already up and you’d have to dig through peoples’ lawns and driveways, it becomes prohibitively expensive,” Garvin says.

For example, in a new suburban neighborhood, installing ordinary overhead power lines costs about $194,000 per mile on average. Installing underground power lines would cost $571,000 per mile. And to retrofit an older suburban neighborhood with underground lines, the costs climb up to an average of $724,000 per mile.

For high-voltage transmission lines—the thick cables typically slung between towers that carry electricity across long distances—new underground installations can cost as much as $23 million per mile. Those costs get deflected to the consumer.


Underground power lines aren’t infallible either; damage from flooding, dig-in events, and other accidents can occasionally cause power outages. And when power outages do occur across underground systems, the damage is harder to locate and requires more time and money to repair. In July 2006, thousands of people in the Queens borough of New York City went without power for nine days during a heat wave. The electric company blamed the blackout on underground cables. Underground power lines can also be less adaptable, harder to upgrade, and have longevity of about 20 years less than overhead power lines, according to the EEI report.

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