Oklahoma Utilities Take Steps to Minimize Ice Storm Damage

One year after an ice storm knocked out power to a half million homes and businesses in Oklahoma, utilities are taking steps to minimize the impact should a similar storm hit the state again.

Officials with the state’s two largest electric utilities – OG&E in Oklahoma City and Public Service Co. of Tulsa – say they have been working to trim trees, bury some power lines and make a variety of improvements to their distribution systems. But both also acknowledge there is little that can be done to prevent widespread damage when a major ice storm hits.

“Ice is the utility’s worst nightmare,” said Brian Alford, a spokesman for OG&E, the state’s largest electric utility, “typically because it’s widespread and very damaging to the system.”

On Dec. 2, OG&E plans to file a request with the Oklahoma Corporation Commission to recover $115 million in costs over the next six years associated with system “hardening,” a term used to describe efforts to insulate the electric grid from severe weather.

Alford said the company is placing lines under ground in new construction, aggressively trimming trees back from power lines and installing “breakaway” connections at power poles that allow for quicker restoration of power in the event of a downed line.

PSO, which provides power to about 525,000 customers in eastern and southwestern Oklahoma, also has targeted about 20 neighborhoods, mostly in Tulsa, for burying transmission lines that workers had a difficult time reaching after the 2007 storm.

“Typically, that’s going to be lines that go along back yards where we can’t get our trucks back there to work on them,” said PSO spokesman Stan Whiteford. “Those are the ones that have a history of tree-related outages.”

At least 29 people lost their lives in the wake of the Dec. 8, 2007, storm, which knocked out electric power to more than 640,000 homes and businesses across the state. The storm developed after a blast of cold arctic air slipped beneath an upper-level system of tropical moisture, so that rain froze and became ice on contact with the surface.

The storm was particularly devastating because it hit the state’s two largest metropolitan areas – Oklahoma City and Tulsa. Electric lines and tree limbs, coated with thick layers of ice, came crashing down, often dragging down power poles and electric meters attached to homes.

But Whiteford said the storm also had the effect of thinning out much of the overgrown vegetation that posed a threat to power lines.

“Quite frankly, there was quite a lot of tree damage last year that thinned things out quite a bit,” he said. “It also allowed us access to areas we might not have seen.”

As for this year’s extended winter forecast, Oklahoma is expected to see warmer temperatures and more precipitation than last year, although it’s impossible to predict if conditions will be ripe for another ice storm, said Christine Riley, a meteorologist with the National Weather Service in Norman.

“It’s tough to say, because there could be the occasion where there is rain and then a cold burst coming down,” she said.

The average temperature in November was 51 degrees, two degrees warmer than the November average of 49 degrees, and it reached 83 degrees in Oklahoma City on Nov. 2, tying a record high set in 1924, Riley said.

The National Oceanic and Atmospheric Administration’s 2008 winter outlook shows a greater than 50 percent chance that most of Oklahoma will be warmer this year compared to last year. The same projection shows the northern half of the state with a greater than 40 percent chance of seeing more precipitation than last year.