“The proposed line will address thermal and voltage issues identified by SPP,” Evergy said in its application. “The line connects to central Kansas at a major wind power interconnection point and will create a completed pathway toward the areas impacted by Winter Storm Elliot to mitigate west-to-east congestion, improve voltage support, and allow increased market access which will reduce market prices.
“The proposed line will benefit electric customers both inside and outside of Kansas, creating reliability and economic value from which the SPP membership can benefit.”
The SPP has intervened in the KCC case.
“SPP is the most appropriate party to provide information to the Commission demonstrating the need for and the benefit of the Project,” attorneys for the SPP said in a KCC filing.
The KCC has scheduled two public hearings on Jan. 7 in Sedan and Jan. 8 in Winfield. Both will offer virtual attendance via Zoom and will be livestreamed on YouTube. The KCC has various deadlines for the parties involved ahead of a March 11-12 evidentiary hearing in Topeka and the May 13 due date for the commission’s order.
Where will the transmission line be?
The project is known in SPP documents as the Branson 345 kV overlay projects. It consists of three parts with a total cost of nearly $1 billion.
It starts with an approximately 155-mile line from the Buffalo Flats substation in Kansas, to Delaware, Oklahoma. In a January 2025 report, the SSP estimated a $484 million cost for that part.
The second part is an approximately 115-mile line from Delaware to Monnett, Missouri, with an estimated cost of $343 million. The third part is an approximately 47-mile line from Monnett to Branson, with an estimated cost of $166 million.
Evergy will build the 133-mile portion of the line between the Kansas border and the Buffalo Flats substation near Garden Plain. It will cross Sedgwick, Sumner, Cowley and Chautauqua counties before crossing the border into Oklahoma.
The application identified 457 landowners within 1,000 feet of the proposed route, all of whom have been notified by Evergy.
Evergy will have a right-of-way along the transmission line. The company said it will provide one-time payments to landowners, who will be allowed to do some agricultural activities in the right-of-way.
Why Evergy says Kansas will benefit from transmission line
In documents submitted to the KCC, Evergy said the line is needed because, “The new infrastructure will enhance electrical reliability for Sedgwick, Sumner, Cowley and Chautauqua counties, surrounding communities and Kansas as a whole, as well as strengthen the regional power grid and prepare for growth. This line will also allow power to be delivered in both directions.”
“This project will benefit residents and businesses in Sedgwick, Sumner, Cowley and Chautauqua counties, south-central and southeast Kansas and beyond by strengthening the regional power grid and improving reliability,” Evergy added. “It also will provide tax revenue, construction jobs, local expenditures and expand capabilities for future investment in area industry.”
But SPP documents indicate the transmission line is primarily intended to benefit southwest Missouri.
SPP says project will address Missouri issues from winter storm
One SPP report, which was included in Evergy’s testimony submitted to the KCC, identified the three-part line as an extreme winter weather project.
“As a complete package, these projects showed substantial reliability benefits and mitigated numerous voltage violations in the Branson area,” the report said.
The transmission line goes through northeast Oklahoma, which means it will be “located near the city of Tulsa where multiple conventional generation plants are located,” the SPP said. “Tying into this area will continue to support and increase the voltage levels in southwest Missouri.”
The transmission line project resulted from the SPP’s 2024 Integrated Transmission Planning process and is intended to address electrical grid concerns in Missouri following a winter storm in 2022.
“SPP staff selected the 345 kV overlay project from Buffalo Flats to Delaware to Monett to North Branson to enhance robustness and resiliency of the transmission system in the southern Missouri area near Branson to address recent extreme winter weather events,” an SPP ITP report said. “Many of the needs identified in this area were low voltage that were driven by a lack of supporting EHV transmission and generation deliverability to the region during Winter Storm Elliott.”
A FERC report on Winter Storm Elliott said southwestern Missouri and northeastern Oklahoma experienced “depressed local voltage conditions.” Transmission operators in the Branson area implemented a “load shed” to “alleviate the low transmission voltages.” Load shedding is the temporary shutdown of electricity in an area, typically through rolling blackouts, to prevent more widespread and prolonged blackouts.
“The 345 kV overlay project involves the construction of approximately 316 miles of 345 kV transmission line, extending from southern Kansas to northeastern Oklahoma and into southwestern Missouri,” the SPP ITP report said. “This project offers significant advantages by enhancing the transmission of low-cost energy to eastern areas of the SPP footprint. Additionally, it boosts power transfer capacity and improves reactive power support in the region, delivering substantial benefits in terms of reliability and resiliency.”
The SPP ITP report said the project brings “reliability under extreme winter conditions, as well as reducing cost to load in southwest Missouri.”
“Ultimately, the project contributes to a more robust transmission system, better equipped to handle increased load growth and withstand extreme weather conditions,” the SPP ITP report said.
Kansas electricity customers will have to help pay to build transmission line
Evergy’s preliminary cost estimate for the project between Buffalo Flats and Delaware is $493 million, but that includes the portion in Oklahoma being built by American Electric Power Company.
“Evergy customers will only pay for a percentage of the total cost of the line based on SPP pricing zones,” the Evergy application said.
Lisa Starkebaum, a senior manager of regulatory affairs at Evergy, said in testimony that the costs will be recovered based on SPP methodology.
For the line from Kansas to Oklahoma, the cost will be allocated regionally across the SPP, Starkebaum said. About 16% of the total costs of the line will be allocated to all of the pricing zones in Kansas, with about 9.36% allocated to customers in Evergy Kansas Central pricing zones.
“This amount will be added to the rates that SPP charges to Evergy and other utilities in Kansas for transmission service,” Starkebaum said.
Evergy charges retail customers a transmission delivery charge, which is used to recover the amount of money paid to the SPP for transmission service.
“Evergy estimates that its portion of the proposed project will cost approximately $5.5 million and will be in service in 2029,” Starkebaum said. “The cost to customers will be the highest in the first year the project is in service and will decline over time as the assets depreciate. For an average residential customer using 1,000 kWh per month, the impact would be $3.37 per year in 2029 and decline each year thereafter as the asset depreciates.”
An Evergy exhibit shows the cost for an average residential customer was calculated using the $493 million estimated total cost, which has a $59 million annual transmission revenue requirement. Evergy Kansas Central’s regional allocation of 9.36% is multiplied by the $59 million, which results in about $5.5 million in allocated to the Evergy Kansas Central zone.
Evergy then used its 2024 residential energy amount and residential cost allocation to determine a cost of about $0.28 for 1,000 kilowatt-hours per month. That results in $3.37 per year.
As reported in the Topeka Capital Journal
