If Power Lines Fall, Why Don't They Go Underground?

Feb 1, 2012

Last month, a week of winter weather cut power to hundreds of thousands of people in the Seattle area for several days.

A lot of those people were left pondering an old question: Why are their neighborhood power lines strung aboveground?

Nobody seems to have a complete answer.

Weather and tree branches cause 40 percent of power outages in the U.S. Another 8 percent are caused by traffic accidents, like cars hitting poles. Forested suburbs are especially vulnerable. Washington — the Evergreen State — routinely ranks among the top 10 states for total number of outages.

"It's only recently I realized, when all the power was going out, that we still have the lines near all the trees," said Pete Mirage, as he picked up branches outside of his church in Renton, Wash., after the latest winter storm. His mother in suburban Tacoma, Wash., had no power for two days after the storm.

Mirage just moved back to the U.S. from the Caribbean, where he was used to storm outages. But he was surprised to find the same problem here. "Power going out was something I experienced in the third world, not in the first world," he says.

Too Expensive To Change?

Other industrialized countries have more of their neighborhood power distribution underground. David Lindsay, an expert at the Electric Power Research Institute, says places like Western Europe have an edge because they rebuilt their cities after the war.

"A lot of the infrastructure there is much younger than it is here," Lindsay says. "Infrastructure in general here dates to before World War II, and it was just added on and added on and added on."

American cities could upgrade by putting wires underground, but that's an expensive proposition.

"The general rule of thumb we use is a factor of 10. Installation costs, construction cost is a factor of 10 difference between overhead and underground," Lindsay says.

Tom Schooley, with the Washington Utilities and Transportation Commission, says storm outages sometimes get communities talking about moving their lines underground, but it doesn't last long. "Whenever people mention it, or some municipality wants to do it underground and they see the expense, they say, 'Oh, well, never mind,' " he says.

Repair Costs 'Not Part Of The Conversation'

So there's a barrier in the upfront cost, but what about the long-term savings? Storm after storm, there's overtime pay for out-of-state repair crews, not to mention what outages cost businesses.

"It's an interesting question, and I have to say, it's literally not part of the conversation people have," Schooley says.

Stephen Hammer, a professor of energy planning at MIT, says he's searched the literature in his field for any analysis of what it costs us to keep fixing those overhead wires.

"Some things are just never raised," he says. "And I think [that's] touching on an issue that we just never get to until there is some ... crisis when the wires come down and we're saying, 'Why do we do this? Why do we keep doing this?' "

Not Enough Cost-Benefit Analysis

One exception is Florida. The state has told utility companies that next time there's a hurricane, they should track the expense of fixing aboveground lines so it can be compared to the maintenance costs of underground lines.

And the result could go either way. Schooley, of the Washington Utilities and Transportation Commission, says it's important to remember that underground wires are not foolproof. "Undergrounding doesn't mean it's totally safe or totally uninterrupted," he says. "It may have different interruptions; it might survive a storm, but it doesn't survive a backhoe."

So the bottom line is — nobody knows the bottom line. Nobody's gone past the cost side of the cost-benefit analysis. Even if cities like Seattle had the money for undergrounding, there's no way to know if it's a good investment, and they have little incentive to change how things are done.

After another storm, a friendly lineman with Seattle City Light named Scott Rice lashes one pole to another with what looks like piano wire. He says the pole broke off because a tree hit the phone lines. But he doesn't wish all of that were underground.

"Well, no; then I wouldn't have a job," he laughs.

And as things stand, Rice doesn't have to worry about his job security.

Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.