As people throughout New Jersey sat without power - some for more than a week - following the pounding the electrical grid got from Hurricane Sandy, many were asking the same question:
How can we keep this from happening again?
A tempting answer is to bury power lines. Sandy, which cut off electricity to more than 8.5 million homes and businesses in 21 states, is the latest power-zapping disaster in a recent string that includes Tropical Storm Irene in August 2011, an October 2011 snowstorm and the June derecho. In each one, falling tree limbs, downed poles and storm-damaged transformers were responsible for many of the outages. Why not put everything safely underground?
But evidence suggests we can't just bury the problem. Underground lines are neither an easy nor a cheap answer.
While many newly developed neighborhoods have underground power lines, that is primarily an aesthetic decision, and it is less expensive to put lines underground as part of new construction.
Moving existing lines underground can cost more than $2 million a mile in a city and more than $700,000 a mile in suburban areas, according to a 2009 study by the Edison Electric Institute. The average cost for a mile of overhead line is less than $200,000.
That's a big difference for the ratepayers who would pick up the tab. Studies in North Carolina and Florida showed that underground distribution lines would require rate increases of between 80 percent and 125 percent.
New Jersey's Division of Rate Counsel, which represents the interests of utility customers, maintains that moving the entire grid underground is too expensive to be practical. Director Stephanie Brand told Bloomberg News, "It would be insane. It's extremely expensive. If it's a million dollars a mile, which is a figure I've heard, you'd have to have 50 of these storms before it would start to pay for itself."
Overhead lines are also easier and cheaper to maintain and upgrade. And underground lines are not invulnerable to storm damage. Flooding, especially saltwater flooding, can cause outages and long-term damage to underground lines, and the roots of falling trees can rip up underground cables.
And while outages with underground lines are less frequent, they are harder to troubleshoot and repair, leading to longer blackouts.
A better solution may be to make investments in shoring up the weakest links in the power grid. Some experts suggest using concrete utility poles to replace wooden ones, or investing in automatic systems that bypass failed circuits to limit the length of outages.
Charlie Driggs, Atlantic City Electric Co.'s strategic initiatives manager, said there are also safety issues with underground power lines. "You have to bury it, ground it, build conduits, and if someone comes to drill through the ground into a conduit, it may cause instant potential for death - and that could be someone drilling for a mailbox."
If only it were as easy as simply putting power lines underground.