A proposed $72 million 40-mile long transmission line between the cities of Piedmont and Luther advanced another step this week with the signing of an Interconnection Agreement by the involved parties.
The deal for the 345-kV Mathewson-Redbud transmission line,
expected to be finished by 2027-2028, was agreed to by Transource Oklahoma, LLC and AEP Oklahoma Transmission Company, Inc, with the Southwest Power Pool as signatory. Transource Oklahoma LLC is a partnership between American Electric Power and Evergy.
The line is being built reportedly to “enhance grid reliability and reduce costs. The developers claim it will provide $16.8 million in initial congestion savings. Supported by the SPP, it is designed to increase power reliability in the central part of the state and reportedly will lead to estimated savings of $138 million to $225 million over a 40-year period.
A recent announcement from the SPP said the Interconnection Agreement was signed December 19, 2025. The SPP stated,
“The filing was publicly noticed. No protests or adverse comments were filed. Pursuant to Rule 214 of the Commission’s regulations (18 C.F.R. § 385.214), notices of intervention, timely-filed motions to intervene, and any unopposed motions to intervene out-of-time filed before the issuance date of this order are granted.”
It also represented final agency action.
The SPP selected Transource to Construct Oklahoma Transmission Project in May of last year.