Why restoring power can take so long

Nov 01 - USA TODAY

 

The most frustrating, depressing, annoying and disruptive news someone suffering without power for several days can get: It may be out for at least another week.

Groans can be heard from Lower Manhattan to Westchester County to the Jersey Shore as utility companies warn residents battered by Hurricane Sandy that it may well take that long for the lights to come back on.

The length of the ordeal comes as no surprise to experts who know what it takes to get flooded substations and downed power lines up and running again.

"A disaster of this magnitude, it's going to take some time," says Robert Puentes, senior fellow at the Brookings Institution's Metropolitan Policy Program whose relatives had to evacuate flooded Little Ferry, N.J., and found shelter with relatives who don't have electricity.

Take the flooding in New York City that sent water sloshing into underground power substations. The water has to be pumped out and the equipment thoroughly dried.

"Restoring a flooded substation takes much longer than restoring a downed power line damaged by ice or wind," says Nicholas Abi-Samra, an expert on the effects of extreme weather on the electricity grid.

A substation is where power is transferred from the high-voltage system -- called the grid -- to the customers. Each large substation is the source of power for thousands of homes and businesses.

"Even small amounts of moisture and dirt contamination can render some electric equipment inoperable," says Abi-Samra, vice president of asset management at Quanta Technology, an energy consulting firm based in Raleigh, N.C.

Breaker mechanisms may have to be disassembled and cleaned manually, and items such as bearings, pins, cylinders, rings, latches and gaskets may need to be replaced. Power cables might need replacing, too. "The problem with the cables can become even more acute when flooding is from saltwater," Abi-Samra says.

That's what Con Edison is dealing with in New York City. "It's a very intensive process," says John Miksad, senior vice president of electric operations.

Once the water is pumped out, the more plodding work begins. "We're doing inspections, drying with fans or blowers, cleaning to make sure that the saltwater that entered the structure is removed," Miksad says. "We're replacing components that are defective. In some cases, changing out entire pieces of equipment."

The first underground network in the lower tip of Manhattan was restored Wednesday afternoon. It serves 2,000 customers (one customer can be an entire building).

But the largest probably won't be running until Friday or Saturday. The flooded East 13th Street station serves 220,000 customers.

New York Gov. Andrew Cuomo said Wednesday that water is receding from subway stations in Lower Manhattan -- crucial for restoring power because Con Edison keeps much equipment in subway tunnels.

It will take another three days or so to restore power to those served by underground stations, despite the flooding and risk of corrosion, because utility workers at least can get to them. Those who get their electricity from above-ground poles and towers may not get power for at least seven days because roads are blocked by water or fallen trees. "More than 100,000 primary wires are down in our service territory," says Con Edison spokeswoman Sara Banda.

"They were ripped to pieces, to shreds," Puentes says. As damaging as water can be to underground stations, at least the equipment stays in place: "It's almost easier to fix that."

The destruction to above-ground stations and power lines may reignite interest in installing underground systems, widely used throughout Europe and Japan, Puentes says.

"There's going to be enthusiasm to do it," he says. "It's expensive and at a time we're still suffering the effects of the recession. But it does raise a larger question: How do you rebuild infrastructure? Does it make any sense to rebuild things exactly the same?" Any enhancement will not cost millions but "billions of dollars," Miksad says.

(c) Copyright 2012 USA TODAY, a division of Gannett Co. Inc.

(c) Copyright 2012 USA TODAY, a division of Gannett Co. Inc.  To subscribe or visit go to:  www.usatoday.com