Underground lines not a 'silver bullet' against outages

With the third widespread power outage from severe storms in just over a year, some may wonder whether it's time for the overhead power line to go the way of the manual typewriter.

Since the majority of outages are caused by wires downed by falling trees, high winds or toppled poles, wouldn't it make sense to bury the lines?

"We have conversations with customers and town officials all the time about it," Mitch Gross, spokesman for Connecticut Light & Power, said last week, while the utility was in the throes of repairing more than 600,000 storm-related outages. "We're not against undergrounding. But it's a major undertaking at a very high cost."

Still, after last week's storm, some are asking whether it might be a worthwhile investment.

"There's no question that would be the ideal situation," said Steven Hartford, town manager in Westerly, one of the many communities with widespread outages since Hurricane Sandy hit Monday. "The majority of outages were due to trees on lines."

The town encourages underground lines for new developments, he said, but is not actively pursuing it for developed areas because of the high cost.

In Mystic, a recent streetscape project moved utilities underground along West Main Street, from the drawbridge to High Street, and along sections of Pearl and Gravel streets, project manager and chief inspector Rick Norris said. Service was activated about a month ago.

"There was some flooding of the lines and we did lose power, but the power's back now," he said Thursday morning. A transformer failure also contributed to the outage.

The main advantage of downtown Mystic's underground utilities , Morris said, has been to "free up sidewalk space and clear the sky."

A short distance away in the Mystic Glen section of town, power lines have been underground the since the neighborhood was built about 20 years ago. But power seems to go out there as much as in any other part of town, resident Linda Wagner said.

"Aesthetically, it's very pleasing," she said Friday, as she and her neighbors were into their fourth day in the dark. "But there's no guarantee you'll have power."

Burying power lines "can improve reliability," said Peng Zhang, assistant professor of power engineering at the University of Connecticut. "But it's not a silver bullet."

In addition to the high cost, he said, there are also some technical challenges. Although outages may be less frequent when lines are buried, electrical service can be lost due to flooding, heat wave, transformer failure and other causes. And diagnosing the problem can be more difficult, Zhang said.

But sophisticated sensors to find underground transmission problems more quickly are being developed, he added.

Despite these qualified endorsements for underground systems, Chaplin Barnes, executive director of the Watch Hill Conservancy, is convinced underground lines are a better way to transmit power in vulnerable coastal communities like Watch Hill. In 2008, the village began a project to bury power lines along its main roads at a total cost of $5.5 million.

Funds raised through grants and other sources have thus far paid for underground lines along Fort Road, and work on Bay Street, the main commercial thoroughfare, will begin next week, he said.

"In storms, you get tangled wires and snapped poles, but with underground lines, you're dealing with something that can just be turned back on again," he said. "Initially, this was an aesthetic project, but now we believe it's absolutely best for safety and economic security for Watch Hill, because there are so many problems after storms because of overhead utilities."

Dennis Schain, spokesman for the state Department of Energy and Environmental Protection, said burying power lines makes the most sense in new developments. And if an existing community is hoping to be retrofitted with underground utilities, it's best to wait until the ground is dug up for some other reason - new sewer, water or gas lines, for example - and to do the work then.

Energy officials at DEEP "took a hard look at undergrounding" as part of a project to help the state better cope with severe weather and outages, said Alex Kragie, special assistant to DEEP Commissioner Daniel Esty. The project concluded that while buried lines are less prone to outages and may make sense for some communities, it isn't a cost-effective statewide solution.

Instead, Kragie said, the state is launching a pilot project this year to create "microgrids" in seven to 15 town centers, and is offering $15 million in grants to municipalities. Essentially, each town center in the project would have its own small transmission system powered by a fuel cell, natural gas micro-turbine or some other generation source that would provide electricity for essential services in a central area, including a grocery store, a shelter and emergency operations center, a fire station and a gas station.

"That way, even if you don't have power, there'll be a place nearby where you know you can get power," Kragie said.

Power lines for the microgrid system likely would be underground.

On Thursday, from 2 to 6 p.m. at its headquarters in Hartford, DEEP will meet with municipal officials about the microgrid project. Interest has been strong, Kragie said.

j.benson@theday.com

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