WASHINGTON — In the aftermath of storms that knocked out power to millions, sweltering residents and elected officials are demanding to know why it’s taking so long to restring power lines and why they’re not more resilient in the first place.
The answer, it turns out, is complicated: Above-ground lines are vulnerable to lashing winds and falling trees, but relocating them underground incurs huge costs — as much as $15 million per mile of buried line — and that gets passed onto consumers.
With memories of other extended outages fresh in the minds of many of the 1.26 million customers who still lack electricity, some question whether the delivery of power is more precarious than it used to be. The storms that began Friday killed 24 people in seven states and the District of Columbia.
“It’s a system that from an infrastructure point of view is beginning to age, has been aging,” said Gregory Reed, a professor of electric power engineering at the University of Pittsburgh. “We haven’t expanded and modernized the bulk of the transmission and distribution network.”
The powerful winds that swept from the Midwest to the Mid-Atlantic late Friday, toppling trees onto power lines and knocking out transmission towers and electrical substations, have renewed debate about whether to bury lines. District of Columbia Mayor Vincent Gray was among officials calling for the change this week and was seeking to meet with the chief executive of Pepco, the city’s dominant utility, to discuss what he called a slow and frustrating response.
“They obviously need to invest more in preparing for getting the power back on,” said Maryland state Sen. James Rosapepe, who is among those advocating for moving lines underground. “Every time this happens, they say they’re shocked — shocked that it rained or snowed or it was hot — which isn’t an acceptable excuse given that we all know about climate change.”
Though the newest communities do bury their power lines, many older ones have found that it’s too expensive to replace existing networks.
To bury power lines, utilities need to take over city streets so they can cut trenches into the asphalt, lay down plastic conduits and then the power lines. Manholes must be created to connect the lines together. The overall cost is between $5 million and $15 million per mile, according to the Electric Power Research Institute, Inc., a nonprofit research and development group funded by electric utilities. Those costs get passed on to residents in the form of higher electric bills, making the idea unpalatable for many communities.
Pepco’s initial estimates are that it would be a $5.8 billion project to bury power lines in D.C. and would cost customers an extra $107 per month, said Michael Maxwell, vice president of asset management.