Big Stone South to Alexandria to Big Oaks transmission project
Several utilities are jointly pursuing permits and approvals from the Minnesota Public Utilities Commission (Commission) for the proposed Big Stone South—Alexandria—Big Oaks transmission project (the Project). The Project consists of approximately 208 miles of new 345 kV transmission facilities between the Big Stone South substation near Big Stone City, South Dakota, and the Alexandria substation near Alexandria, Minnesota. There would also be a new substation (Big Oaks substation) proposed southwest of Becker, Minnesota. The Project also includes expansion of the Alexandria, Riverview, and Quarry substations.
Remaining approvals needed
In order to be built, the Project requires three approvals from the Commission. The Commission granted a certificate of need for the entire project and a route permit for the eastern portion of the project in Fall 2024. The remaining permit required is:
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a route permit for the western portion of the project (Big Stone South to Alexandria).
Route description
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The western segment (Big Stone South to Alexandria Project) of the Project includes a new approximately 91- to 105-mile 345-kilovolt (kV) double-circuit capable transmission line from the Minnesota-South Dakota border to the existing Alexandria Substation near Alexandria, Minnesota. Only a single-circuit will be installed initially. The BSSA Project would be located in portions of Big Stone, Swift, Stevens, Pope, and Douglas counties. This portion of the project is currently under consideration.
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The eastern segment (Alexandria to Big Oaks Project) of the Project, currently under review, would entail construction of an approximately 105- to 108-mile 345-kV transmission line from the Alexandria Substation to a new Big Oaks Substation. As proposed, the transmission line would be collocated on existing double-circuit-capable structures and within existing transmission line right-of-way for more than 95 percent of its length. This portion of the project has been permitted.
Calendar of events
Project Background
Utilities: Great River Energy, Minnesota Power, Otter Tail Power Company, Western Municipal Power Agency, Xcel Energy, Missouri River Energy Services
The Project was a part of the Tranche 1 Portfolio approved by the Midcontinent Independent System Operator, Inc. (MISO). The Applicants state that the Project is needed to provide additional transmission capacity and to improve electric system reliability throughout the region to accommodate the addition of renewable resources.
The existing double-circuit capable CapX2020 transmission line was previously permitted and constructed as part of the Monticello to St. Cloud 345 kV Transmission Project (Docket No. E002, ET2/TL-09-246) and the Fargo to St. Cloud 345 kV Transmission Project (Docket No. E002, ET2/TL-09-1056).
Utility Project Website Big Stone to Alexandria
Utility Project Website Alexandria to Big Oaks
Department of Commerce Website (Alexandria to Big Oaks)
Docket numbers: CN-22-538 (certificate of need for the entire project); TL-23-159 (eastern portion); TL-23-160 (western portion)
More Information
To learn more about the project and see document that have been filed regarding it, please visit the Commission's eDockets site. Use the docket numbers above to search for additional information.
Submitting Comments
To submit comments into the official record, please go to the Commission's Comment page and learn more. Submitting comments into the official record is the only way to get them before the Commissioners for consideration.
Have a Question?
Email: publicadvisor.puc@state.mn.us
Call the Commission @ 651-296-0406