Thursday, December 1, 2011

On power lines

Fortune had an interesting piece today discussing the economics of power lines--specifically, the economics that lead utility companies to suspend most wires from utility poles (subjecting us to frequent power outages, especially in the winter) rather than burying them underground. Per the article:
The freak snowstorm that hit the Northeast on Halloween weekend felled branches and trees at a dizzying rate -- New York City's Central Park alone lost 1,000 trees -- and downed hundreds of power lines. The blizzard left some 2 million without electricity -- many for more than a week. The even weirder thing is that this didn't really need to happen. As severe storms become more frequent and the losses from closed businesses and absentee workers add up, one is tempted to ask a very simple question: Why don't we bury our power lines?
Well, it turns out the answer isn't so simple. Numerous studies conducted by utilities over the years conclude that it is not economically feasible to bury lines. The most common estimate is that it costs 10 times more to bury them than to string them on poles. The North Carolina Utilities Commission said that burying wires statewide would cost $41 billion, take 25 years, and would more than double monthly electric bills. The news gets more discouraging. Some experts say that underground cables are more reliable than those above ground but only by about 50%, and that advantage is somewhat counteracted when you consider that it takes much longer to find, dig up, and repair a faulty wire. Why do underground cables fail at all? Floods and earthquakes can short lines. There's more: The roots of a tree toppled in a storm could destroy a buried wire.
Is it that hopeless? Maybe not, argues Gerry Sheerin, an engineer and consultant in Ontario, who thinks the studies on cost and reliability are out of date and too high, perhaps by a factor of two. "Putting wires underground is absolutely a last resort with utilities, so they don't have much experience doing it and tend to overestimate the difficulties involved." That said, most new housing developments today bury their cables, helping the industry to gain experience. A nationwide program to bury wires could create economies of scale that would drive down costs. Also, new sensor technology could help spot breaks in underground lines, speeding repairs.
Down here in Virginia, I live in a (relatively new) development where the majority of lines are buried. This doesn't eliminate power outages entirely, but it definitely speeds the repair process--most of the outages we experience are exceedingly temporary.

But what's most noteworthy to me about this article isn't so much that the economics of air-versus-ground may be shifting toward ground, but that it's presumed that these are the only two options. With all of the fantastic technological advances that we're seeing elsewhere, how is it that we haven't been able to come up with a more efficient alternative?

I'm of course just spouting random nonsense off the top of my head here, but doesn't it seem like there could be some other options--like embedding or attaching power lines to the sides of roads, or embracing/augmenting wireless technology, or basically anything that straddles the line between "hanging in the air" and "buried under the ground"? There seems to be a whole lot of uncovered territory between the two extremes that we're discussing, but for some reason it gets ignored completely. Why is that?


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