Construction Begins on SWIP-North 500 kV Transmission Line in the U.S.

en.Wedoany.com Reported - On September 3, LS Power's Great Basin Transmission held a groundbreaking ceremony for the Southwest Intertie Project-North (SWIP-North) in Ely, Nevada. The project has entered the construction phase as of summer 2026, involving the construction of an approximately 285-mile (about 459 km) 500 kV high-voltage transmission line connecting the Midpoint Substation near Twin Falls, Idaho, with the Robinson Summit Substation near Ely, Nevada. The total project investment exceeds $1 billion, with completion scheduled for 2028.

Great Basin Transmission is responsible for the development, permitting, financing, construction, ownership, operation, and maintenance of SWIP-North. California ISO selected the company to advance the project in 2023, with final cost recovery arrangements approved in 2024; Idaho Power received regulatory approval to participate in the project in 2025. The project has now transitioned from years of planning and permitting into actual construction, with the construction period expected to last until 2028.

SWIP-North is designed with a transmission capacity of approximately 2,000 MW. Once operational, the line will form a 500 kV transmission corridor across the western United States together with the already-completed One Nevada Transmission Line (ON Line) and DesertLink. ON Line spans approximately 231 miles and was placed into service in 2014; DesertLink spans approximately 60 miles and was placed into service in 2020. Upon completion of SWIP-North, the entire transmission corridor will reach approximately 576 miles, extending from the Magic Valley region in Idaho to the Eldorado Valley in Nevada, south of Las Vegas.

Regarding line capacity arrangements, California ISO, NV Energy, and Idaho Power all hold relevant transmission capacity rights. According to the arrangement announced by Great Basin Transmission, NV Energy bears the full cost of the existing ON Line, while LS Power bears the full cost of SWIP-North, with both parties sharing the capacity of the entire transmission corridor through an agreement; LS Power subsequently allocates a portion of the capacity rights to California ISO and Idaho Power. Idaho Power holds 250 MW of the south-to-north transfer capability on SWIP-North and has usage rights to an additional 250 MW, meaning that up to 500 MW of northbound transmission capacity can be provided to Idaho Power customers once the project is operational.

The U.S. Department of Energy previously supported the project through the Transmission Facilitation Program. According to DOE materials, the SWIP-North project has a scale of 2,070 MW and 285 miles, with an original plan to provide $331 million in federal support through a capacity contract. However, project sponsors including GBT Northbound subsequently filed termination notices, and the capacity contract agreement was terminated on June 30, 2026. As a result, this $331 million can no longer be counted as secured federal funding for the current project in this construction financing.

In terms of project permitting, SWIP-North is not a newly initiated transmission line plan. The U.S. Bureau of Land Management had previously completed the project's environmental review and secured federal land rights-of-way, and all easements required for the approximately 76 miles of line within Idaho have also been fully secured. More than 70% of the project's line is located in Nevada. Construction at this stage will continue to advance the 500 kV line and associated substation facilities. Great Basin Transmission estimates that the construction phase will create approximately 300 construction jobs.