August 2008 Vol. 63 No. 8
Business
Oklahoma Weighs ‘Undergrounding’ Options For Power Grid
The Public Utility Division of the Oklahoma Corporation Commission (OCC) has completed an investigation into measures that could be taken to protect the state’s power infrastructure from ice, wind and other disasters that have the potential of disrupting electrical service. Some of the measures could have a substantial impact on underground construction.
The three member commission held a public hearing on the issue June 30. No action was taken, but commissioners requested its staff to prepare recommendations about which measures suggested in the study should receive priority and to prepare estimates of the costs for implementing them.
The study was undertaken early this year after a December 2007 storm knocked out power to more than 620,000 electrical customers in the state. Some residents and businesses were without electrical service for several weeks.
One of the questions raised following the late 2007 storm was why more of the state’s power lines are not underground where they would be protected from weather related risks. Costs and other issues related to placing more power lines underground were focal points of the study.
Key findings
A preliminary summary of the report released by OCC cites key findings:
• Climatological data support the theory that Oklahoma will experience an increase in the number of storms likely to disrupt electrical service;
• Full immediate undergrounding of transmission and distribution infrastructure would be too costly to be feasible;
• Efforts to increase the ability of the state’s electrical delivery systems to better withstand such storms should be multifaceted and target undergrounding, “hardening” infrastructure and improved vegetation management. Hardening is defined as improvements to equipment that will minimize weather related damage.
The Public Utility Division staff recommends the commission institute legislative and rulemaking processes to determine the feasibility, support and exact requirements for 12 measures:
1. Bury drop [service] lines and/or create a pilot program to test newly available service entrance/disconnect systems.
2. Bury all new lateral distribution lines.
3. Bury existing lateral distribution lines when requested by a majority of customers in a neighborhood.
4. Identify “fully urbanized” main distribution lines [lines that are at capacity for lateral line connections] and require their burial when the line is replaced as part of normal maintenance or repair.
5. Require utilities to bury main and lateral distribution lines when relocation is necessary for major road and highway projects.
6. Harden all highway crossing electrical lines identified as causing disruptions during storms because of falling on roadways.
7. Harden worst performing circuits.
8. Require utilities to erect self standing poles [strongly anchored, reinforced poles] in strategic locations for transmission lines and targeted distribution lines.
9. Encourage installation of backup self generation [a free standing generation unit] at individual locations to provide power during electrical outages.
10. Require installation of backup self generation for vital services.
11. Create incentives for “smart grid” installations that will allow rerouting of electrical power around downed lines, transformers and other equipment.
12. Require more aggressive vegetation management.
A copy of the full report is available on the OCC web site: www.occ.state.ok.us.
Sources
OCC spokesperson Matt Skinner said methodology for the study included requesting data from all retail electrical utilities and cooperatives in the state; gathering information from the Oklahoma Climatological Survey, Oklahoma Department of Emergency Management, Oklahoma Forestry Services, Oklahoma Insurance Department, Oklahoma Highway Traffic Safety Office, and the Oklahoma Tax Commission; reviewing undergrounding studies completed by the states of Florida, Maryland, North Carolina, Virginia and Michigan; and reviewing an Edison Electric Institute study on the topic.
Even as OCC’s Public Utility Division staff members worked to complete the study and report, a rash of spring storms including tornadoes, extremely strong straight winds, lightning and heavy rains repeatedly disrupted power in several sections of the state.
When OCC announced plans to initiate the undergrounding study in January, most power providers expressed support, including the state’s two largest public utilities: Oklahoma Gas & Electric Co. (OG&E), serving Oklahoma City and parts of central and western Oklahoma; and Public Service Co. of Oklahoma (PSO), serving metropolitan Tulsa and portions of eastern and southwestern Oklahoma.
PSO, a business unit of American Electric Power, has an active pilot program started at the request of the OCC to convert aerial cable to underground.
Regarding the OCC report, PSO spokesperson Stan Whiteford said:
“Many of the preliminary report’s key findings and recommendations are in accord with the program PSO began nearly three years ago to convert certain inaccessible backyard overhead distribution lines to front lot underground service. We look forward to working with the OCC as it continues to take a closer look at the issue of overhead to underground conversions.”
OG&E’s corporate communications department did not respond to an invitation to comment for this report.
OG&E has no program to convert aerial cable to underground, and has not announced plans to initiate one. Previous statements by OG&E on the topic have emphasized that the company has been burying power cable in new developments for many years and typically cite high costs of underground construction as the reason for not burying established overhead lines.
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