September 2009 Vol. 64 No. 9
Features
Another Electric Utility Experiments With ‘Undergrounding’
The Oklahoma Corporation Commission (OCC) has authorized Oklahoma Gas & Electric Co. (OG&E) to bill electric customers for programs to make the company’s electrical distribution system less susceptible to power outages caused by the weather by, in some cases, converting to underground cable.
OG&E provides electrical power for the metropolitan Oklahoma City area and portions of central and western Oklahoma. Much of the system suffered damage in December 2007 during the worst ice storm in the state’s history.
The commission authorized the utility company to recover from customers $68.5 million for system improvements. Cost to customers will average between $1 and $2 per month per customer over a three year period, said Brian Alford, OG&E director of corporate communications.
Projected costs include $33.2 million to initiate a four year cycle for removal of tree limbs and other vegetation around power lines and $35.3 million to “harden” the distribution system to make it more resistant to damage from wind, water and ice.
Alford said areas targeted for work primarily will be older neighborhoods that are considered at risk for power outages and will include breakaway connections and upgrading of support structures and circuits at numerous locations.
In some areas, aerial power lines will be replaced with underground cable.
“We will do a pilot underground project of 500 services,” said Alford. “Additionally, we will be converting from aerial to underground the laterals and services on seven circuits.”
HDD
For the conversions, Alford said OG&E typically uses horizontal directional drilling (HDD). Construction is expected to begin in the fall of 2009.
More than 300,000 OG&E customers lost service as a result of the 2007 ice storm; statewide more then 620,000 businesses and residences were without power, some for several weeks.
Following the storm, the OCC Public Utility Division conducted an investigation about ways to protect the state’s power infrastructure from the weather.
The report recognized that full undergrounding of electrical systems is too costly to be feasible but recommended further investigation of several underground options, including burying service lines, placing new lateral distribution lines underground, to bury existing laterals when requested by a majority of the customers in an area, identification of “fully urbanized” main distribution lines that are at capacity limits and require burial when they are replaced, and burying main and lateral distribution lines that require relocation because of road and highway construction.
The state’s other large power supplier, Public Service Co. of Oklahoma (PSO), has had an aerial to underground conversation program under way for several years. PSO, a business unit of American Electric Power, serves metropolitan Tulsa and portions of eastern and southwestern Oklahoma.
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