In a recent application submitted to the Oklahoma Corporation Commission, American Electric Power Transmission Co. requested approval for a project to rebuild a high-voltage power line in three southern Oklahoma counties.
AEP Transco – a subsidiary of Ohio-based American Electric Power, parent company of Public Service Co. of Oklahoma – reported it needs to replace 70 miles of a 43-year-old line and “accompanying facilities” in Comanche, Stephens and Carter counties. AEP Transco said the project will focus on the 345-kilovolt transmission line that extends from the Lawton Eastside electric substation to the Sunnyside substation near Lone Grove.
The company announced it plans to spend $260 million on the project, “based upon current market conditions.”
Construction is expected to begin in July 2026 and completion is projected within three and a half years, by December 2029, according to Nathan M. Koch of American Electric Power Service Corp., another subsidiary of AEP. Koch told the commission his responsibilities include “overseeing and supervising transmission system projects from preconstruction to completion.”
AEP intends to hold public meetings in Stephens, Comanche and Carter counties Nov. 17-21 to explain the project, Koch announced.
“The company will publish notices of the specific time, date and location of the public meetings in newspapers in general circulation in each county and also provide the notice to each respective Board of County Commissioners,” said Koch, of Tulsa.
Barrett A. Thomas of Tulsa, a transmission line engineer manager with AEP Transco, testified in support of plans to rebuild the power line. He wrote in prefiled testimony that reconstruction of the 345 kilovolt transmission line “will address its current condition and reduce the frequency of outages.”
Jeffrey L. Ellis, a transmission planning manager for AEP Service Company, said the Lawton Eastside to Sunnyside line was constructed in 1982. That line has been identified as “a priority for replacement due to its age, deteriorating condition, and declining reliability.” An analysis “considered multiple factors, including outage frequency and duration, structural integrity, customer impact, and overall system performance.”
From Jan. 1, 2019, to Dec. 31, 2024, the Lawton Eastside to Sunnyside line experienced 22 outages, including five forced direct momentary interruptions, 17 forced direct permanent outages, and one forced indirect momentary outage, resulting in a combined transmission system impact of 410.8 hours.
The outages were caused by lightning (three incidents), failed conductor equipment (nine), failed splices (three), structural failure (one), foreign interference (one), relay malfunction (one), and unknown causes (three), Ellis said. “This level of outage activity and duration clearly demonstrates the declining reliability of the line and increasing risk to system stability,” he asserted.
As of Dec. 31, 2024, Ellis testified, there were 49 open conductor conditions, including 40 instances of low sag, seven damaged conductors, one failed splice, and one damaged shield wire.
In addition, he said, 118 structures – representing 25% of the line – have at least one open structural condition. Those include 102 poles damaged by rot, burning, or woodpecker activity; 15 crossarms that are bowed, split, or rotted; and additional failures in braces and other structural components.
Thomas said several improvements are planned: Wooden power poles will be replaced with metal towers
• Existing 40-year-old wooden transmission poles will be replaced with Breakthrough Overhead Line Design (BOLD) lattice towers.
“While wood poles can have a lifespan exceeding 40 years in certain regions, their longevity is inconsistent across geographic areas,” Ellis said.
The BOLD towers will provide several advantages, such as improved structural integrity, longer lifespan, and reduced maintenance needs, Thomas said. “Adoption of this overall design aligns with our goal of modernizing the infrastructure for enhanced reliability.”
The towers will range from 110 feet to 165 feet in height, the company reported. An estimated 375 to 380 BOLD lattice towers will be erected in the three counties.
The existing transmission line is located on existing 130-foot-wide easements, Thomas related. AEP anticipates widening those easements to 150 feet, “to ensure there is adequate space for the infrastructure, maintenance access, and safe operation of the line,” he said.
• The existing line is single circuit, but the new line will be designed to accommodate double circuit capability in the future. “This enhancement will allow for increased transmission capacity, enabling the line to handle a greater load and improve the overall efficiency of power distribution as needs may increase in the future,” Thomas said.
• Included in the overall project is a comprehensive telecommunication component of infrastructure that includes providing and installing various forms of fiber optic lines on and along the entire transmission line rebuild.
It also includes the transition and installation of fiber optic lines from the transmission line structures into both Lawton Eastside Substation and Terry Road Switching Station control buildings. The fiber optic lines serve for company communication, electrical relay protection, control, and static line protection, Thomas said.
• The existing self-dampening conductor, which has reached its 30-year lifespan, will be replaced, he said. “This is critical to ensuring that the transmission line can continue to function effectively and reliably.”
• The work also will involve “comprehensive improvements to the entire transmission line system,” he said. Those will include upgrading supporting hardware, enhancing grounding systems, and ensuring compliance with current industry standards and regulations.
The transmission line upgrade is “crucial for ensuring a consistent power supply to our communities and will support increased load growth,” Thomas said.
Gary L. McClanahan, department manager and project manager in the Environmental Division of POWER Engineers, informed the Corporation Commission about the location of the work. POWER is a wholly owned subsidiary of WSP USA Inc. and is the largest power delivery detail designer in the United States.
McClanahan said the AEP project will begin at PSO’s Lawton Eastside Substation, located approximately two-thirds of a mile north of SH-7 and slightly east of Southeast 60th Street, and will terminate at the Oklahoma Gas & Electric Sunnyside line at structure 86/2. That structure is approximately 1.7 miles north of the Sunnyside Substation three miles northeast of Lone Grove, which is seven miles east of Ardmore.
A related job will entail a “cut-in project” to interconnect a solar generating source that will “tie in with the existing infrastructure,” Thomas said.
The question of cost recovery on the project is unclear, according to Ellis. He said “the retail impact for a residential customer cannot be determined because that is a function of cost-ofservice calculations” prepared by “load serving entities that are allocated a share of this project’s revenue requirement. AEP’s 3-county project won’t be part of AEP’s 5-state line rebuild Matt Rahn, PSO’s region communications manager in Tulsa, said AEP Transco’s 70-mile project is not part of AEP’s plan to rebuild nearly 5,000 miles of electrical transmission lines in five states, including Oklahoma.
U.S. Energy Secretary Chris Wright announced recently that the department’s Loan Programs office closed on a $1.6 billion loan guarantee for American Electric Power Transmission Co.
The loan guarantee was reported to be part of President Trump’s Executive Order, Strengthening the Reliability and Security of the United States Electric Grid, and reportedly will finance rebuilding power lines in Oklahoma, Michigan, Ohio, Indiana and West Virginia.
About 1,400 miles of lines in Oklahoma that serve approximately 1.2 million residents are slated to be rebuilt, Rahn confirmed.
The new lines supported by the federal funding will replace old transmission lines in existing rights-of-way with new lines capable of carrying more energy, AEP said. The projects will create an estimated 1,100 construction jobs, the company predicted.
Tulsa-based PSO serves 575,800 customers (residential, commercial, industrial, and “other”) in 232 cities and towns in eastern and southwestern Oklahoma.
The utility serves more than three dozen communities in southwest Oklahoma, including Lawton, Altus, Duncan, Chickasha, Cache, Elgin, Fletcher, Porter Hill, Sterling, Temple, Hobart, Apache, Temple, Rush Springs, Carnegie, Cement, Cyril, Davidson, Duke, Elmer, Fort Cobb, Frederick, Gotebo, Gould, Grandfield, Granite, Headrick, Hollis, Lone Wolf, Manitou, Martha, Mountain Park, Mountain View, Roosevelt, Snyder, Terral, Tipton and Waurika.