Tri-State moving forward with $186.5 million in transmission system upgrades

• Four major transmission projects under the Eastern Colorado Transmission Expansion, when completed, will have significant benefits for Tri-State’s members. 
• Burlington-Lamar 230-kilovolt transmission line project began in February 2024. 

(April 2, 2024, Westminster, Colo.) Tri-State is continuing to make significant strides to improve and expand its transmission infrastructure network, in an effort to meet the growing energy needs of its members, with an investment of $186.5 million in four major transmission efforts. 

The transmission expansion will increase Tri-State’s availability to add renewable energy resources in eastern Colorado by more than 700 megawatts. The transmission effort also augments Tri-State’s proposed 2023 Electric Resource Plan, which was filed with the Colorado Public Utilities Commission (CoPUC) in December 2023 and identifies 1,250 megawatts of renewable energy and energy storage through 2031.

In February 2024, Tri-State began construction on its Eastern Colorado Transmission Expansion, which involves multiple substations and transmission line work, notably the 230-kilovolt transmission line between its Burlington, Colo., and Lamar, Colo., substations. Tri-State also will modify certain structures on its existing Big Sandy (Limon, Colo.)-Burlington 230-kilovolt transmission line. 

Engineering activities also are underway on a new 30-mile-long, 230-kilovolt transmission line from Tri-State’s Boone Substation near Boone, Colo., to a new Huckleberry switching station south of Pueblo, Colo. In addition, routing activities are underway for a new 80-mile-long, 230-kilovolt transmission line between its Big Sandy Substation near Limon, Colo., and a new Badger Creek switching station south of Fort Morgan, Colo. All of the projects are planned for completion between the first quarter of 2025 and the fourth quarter of 2028. 

“Tri-State is taking an incremental and pragmatic approach to additional transmission needs on our system. Our efforts are designed to take a strategic and cost-effective approach to interconnecting three new transmission lines to our existing network and to improve an existing transmission line. All of these efforts will ensure that we provide reliable service to our members, eliminate system bottlenecks and support future clean energy additions,” said Chris Pink, Tri-State senior vice president for operations.

The four major projects under the Eastern Colorado Transmission Expansion, when completed, will have significant benefits for Tri-State’s members, including San Isabel Electric Association, based in Pueblo, Colo; Southeast Colorado Power Association, based in La Junta, Colo.; K.C. Electric Association, based in Hugo, Colo.; Morgan County Rural Electric Association, based in Fort Morgan, Colo; and Mountain View Electric Association, based in Limon, Colo. 

Tri-State filed for “certificates of public convenience and necessity” (CPCN) on the two of new transmission project, Boone-Huckleberry and Big Sandy-Badger Creek, in February 2022 with the Colorado Public Utilities Commission (CoPUC), which approved the projects in September 2022. The Burlington-Lamar transmission project had been previously approved and modification of the structures on Big Sandy Burlington did not require a CPCN.  

Tri-State noted that it led a task force involving some 60 stakeholders representing some 24 entities at the Colorado Coordinated Planning Group, to evaluate alternatives to meet its transmission needs in eastern Colorado, through multiple meetings between April and September 2021. Stakeholders proposed and Tri-State studied 15 proposals; of the alternatives studied, the proposed projects stood out as the best option that could meet Tri-State's needs, while at the same time being the lowest cost.  

Tri-State supports all statewide transmission infrastructure development in the state, but notes that its Eastern Colorado Transmission Expansion is separate from Colorado’s Power Pathway (CPP), a $1.7 billion proposal by Xcel Energy to deliver generation to the Front Range of Colorado. Tri-State's studies confirm that the CPP project and Tri-State's proposed transmission system improvements will not interfere with each other, and together will help achieve Colorado’s renewable energy and greenhouse gas emission reduction goals.