Why not bury power lines?

Underground power lines can boost grid reliability during winter storms by reducing outages on distribution networks, but undergrounding costs, transmission constraints, and ratepayer impacts challenge utilities like OG&E, PSO, and cooperatives in Oklahoma.

With each major ice storm in Oklahoma, the question seems to resurface: Why not bury the power lines?

The issue has come up again as electricity trickles back on in southwestern Oklahoma, a week after a winter storm left thousands in the region without power. More than 30,000 customers remained without electricity February 4, although utility spokesmen said progress was being made in restoring service.

To complicate matters, another winter storm began moving into the state and forecasters were predicting the possibility of yet another one.

Underground power lines could mean fewer outages during such winter storms. The problem is the cost of burying them, according to Oklahoma Gas and Electric Co., Public Service Co. of Oklahoma and the Oklahoma Association of Electric Cooperatives.

Burying all the transmission lines in Oklahoma would cost an estimated $27 billion, raising customers' bills as much as $270 a month for 30 years, according to a 2008 report by the Oklahoma Corporation Commission's Public Utility Division after an ice storm knocked out power to a wide swath of the state. Transmission lines are high-voltage lines that carry large quantities of power, often over long distances.

The report estimated the cost of putting underground all the distribution lines, which usually carry lower voltages and are used to distribute power in urban and rural areas, was set at $30.5 billion statewide.

"You have to do those things that made good economic sense," OG&E spokesman Brian Alford said. "You have to look at the cost-benefit of putting lines underground."

OG&E has focused more on trimming back trees near power lines and other ways of making its system more resistant to outages instead of putting the lines underground, Alford said — although the company is not opposed to burying lines.

PSO began burying its distribution lines in 2005 but discontinued it in 2009 because of the economic climate, spokesman Stan Whiteford said. He said about 100 miles of PSO's 20,000 miles of distribution lines in Oklahoma were buried during that time.

Whiteford said PSO hopes to resume the program — for which it can recoup its costs from customers — in the future.

Burying transmission lines is impractical, Corporation Commission spokesman Matt Skinner said, and those lines are what caused the major problems in the last storm. He said the commission has supported distribution line burial, "but the problem is who pays for it and how much."

Oklahoma Association of Electric Cooperatives spokesman Sid Sperry said member rural electric cooperatives reported about 20,000 outages on the morning after the storm. He said it could take until February 11 before power is fully restored in some areas.

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