Underground utility lines are less vulnerable in storms, but if damaged, they take longer to repair.
By LOUIS HAU
Published September 9, 2004
The logic seems seductively simple: If local power lines were buried underground, there would be far fewer outages after a bad storm and they'd cost less to maintain over the long run.
After Hurricane Frances moved through west-central Florida over the weekend and cut off electricity to hundreds of thousands of homes, the issue became a hot topic, particularly amid the swelter of powerless neighborhoods.
The Pinellas County beach town of North Redington Beach is proceeding with plans to bury all its residents' power, telephone and cable TV lines. Other Pinellas municipalities have been exploring the possibility for utilities along Gulf Boulevard. And moving utilities below ground has been a continuing topic of conversation on Tampa's Davis Islands.
But utilities and industry experts caution that putting lines underground is no panacea.
For one thing, the cost of installation can be very high, and for another, there are dueling views about how much more reliable underground lines are.
The vast majority of new subdivisions in the area have buried power lines. While underground lines account for only about 20 percent of electricity distribution lines maintained by Progress Energy Florida of St. Petersburg and Tampa Electric Co., they make up 80 to 90 percent of newly constructed lines.
Energy consultant Brad Johnson concluded in January in a report he did for the Edison Electric Institute, a trade group representing investor-owned utilities, that underground lines can be more reliable for customers. Johnson, a former senior executive with Washington, D.C., utility Pepco Holdings Inc., said he found that underground power lines generally sustained fewer power outages, particularly in heavily wooded areas susceptible to falling trees and branches.
But he also noted that outages caused by underground lines took far longer to repair. While damage to overhead lines can be found quickly through simple visual inspections, it takes considerably more time and manpower - and more money - to locate a problem on an underground line and to repair it, he said.
"There are benefits in terms of fewer outages," Johnson said. "But you can't just say, "If you put it underground, you're going to get better reliability.' . . . Just because you put it underground doesn't mean you can just walk away and forget it."
Johnson's report cited a study prepared in November for the North Carolina Utilities Commission that found that "during severe weather events, customers with underground facilities are less likely to be interrupted but will be among the last to have power restored when there is an underground fault."
The North Carolina study concluded that burying all the distribution lines built by the state's three investor-owned utilities would take about 25 years to complete at a cost of about $41-billion. (Johnson said that the cost of installing underground lines in a new subdivision, which are borne by developers and passed on to new home buyers, are far lower than the expense of burying existing overhead power lines.)
None of this dissuades Randy Knight, assistant city manager for Winter Park in Orange County. He suspects Progress Energy and other investor-owned utilities are sometimes leery of underground power lines because of concerns that related expenses could hurt their bottom line.
Hurricane Charley wreaked havoc on Winter Park's canopy of trees, which pulled down power lines all over the Orlando bedroom community. The city, which voted last year to cut its ties to Progress, plans to begin burying its power lines once that break is complete.
Knight said the majority of outages caused by Charley would have been avoided with an underground system, though he conceded that "if you're just looking at it financially, it doesn't make sense."
Progress Energy Florida engineer Sam Nixon, who has managed underground line projects for a number of Pinellas County beach communities, said that burying local lines helps only so much since most of the electricity infrastructure is still above ground. That means the lights still go out if a storm damages a substation, the main distribution line or high-voltage transmission lines.
"You've got to go overhead at some point," he said.
Still, moving underground remains a popular option for some towns and homeowners. That's because aesthetics is a significant motivation. Nixon said overhead lines remain the most cost-effective electricity service, but said that for communities that understand the costs, Progress is willing to help manage such projects and coordinate them with local phone and cable companies. "We really try to stay neutral and make sure they understand the facts," he said.
Times staff writer Susan Thurston contributed to this report. Louis Hau can be reached at 813 226-3404 or hau@sptimes.com
