Great Basin Transmission starts construction on SWIP-North project

Ely, Nevada, Great Basin Transmission, an affiliate of LS Power, has commenced construction on the Southwest Intertie Project-North (SWIP-North), a significant 285-mile, 500 kV transmission line connecting the Midpoint Substation near Twin Falls, Idaho, with the Robinson Summit Substation near Ely, Nevada. The project is set to invest over $1 billion in power infrastructure, enhancing grid reliability, reducing congestion, and expanding access to diverse power supply resources across the western United States.

LS Power CEO Paul Segal stated, "Reliable power increasingly depends on our ability to move electricity across regions, and that requires major investment in transmission. SWIP-North will complete an important new pathway between the Pacific Northwest and the Desert Southwest, improving reliability and giving the Western grid greater flexibility."

SWIP-North is the final segment of the Southwest Intertie Project, first conceived in the 1980s and advanced by LS Power since acquiring development rights in 2005. Once completed, the corridor will span 576 miles, connecting Idaho's Magic Valley near Twin Falls to Nevada's Eldorado Valley south of Las Vegas. More than 70% of SWIP-North will be constructed in Nevada.

"Nevada's position as a strategic energy hub for the West is further solidified with the construction of this last phase of the Southwest Intertie Project," said Nevada Governor Joe Lombardo. "SWIP-North will provide numerous benefits, including additional transmission capacity, new energy import and export opportunities, increased energy reliability for residents and businesses, and enhanced resiliency against extreme weather events and wildfires."

The project will build on two earlier phases developed by LS Power: the 231-mile One Nevada Transmission Line (ON Line), built in partnership with NV Energy and placed in service in 2014, and the 60-mile DesertLink line, placed in service in 2020. Together, these transmission paths create a critical link in the regional grid and enhance reliability through their connection to the California Independent System Operator (California ISO).

Construction on SWIP-North began in the summer of 2026 and is expected to be completed in 2028. Great Basin Transmission was selected by the California ISO in 2023 to develop, permit, finance, construct, own, operate, and maintain the SWIP-North Project, with final cost recovery approval in 2024. Idaho Power obtained approval for participation in the project in 2025.

According to LS Power President Paul Thessen, "SWIP-North represents a unique cooperation between multiple regions, states, and utilities, and a great example of innovation and collaboration between a private developer, LS Power; Western electric utilities, NV Energy and Idaho Power; and a regional grid operator, the California ISO, to balance cost allocation, capacity sharing, and benefits."

The California ISO, NV Energy, and Idaho Power will all share capacity rights on the line. The California ISO President and CEO Elliot Mainzer noted, "Major transmission investments like SWIP-North are essential to building a more reliable, resilient, and efficient Western grid. By creating a stronger connection across the West, this line will give grid operators greater flexibility to move power where it is needed most, improve access to diverse energy resources, and enhance our ability to respond to changing system conditions and extreme weather events."

Mitch Colburn, Vice President of Planning, Engineering, and Construction at Idaho Power, said, "Keeping energy costs affordable for our customers is one of our top priorities. SWIP-North will help Idaho Power meet growing energy demands and reduce costs for our customers by connecting Idaho Power to the Desert Southwest's low-cost energy resources."

Beyond the increased electrical capacity, the project is expected to bring measurable economic benefits to Nevada and Idaho. LS Power Senior Vice President of Development Mark Milburn added, "We estimate the project will add around 300 construction jobs, generate over $375 million in regional economic impact from construction-related activity, and provide millions in property tax revenue each year to help fund essential local services."

Construction on SWIP-North is scheduled to begin in summer 2026 and is expected to be completed by 2028. The full transmission path will be capable of transmitting over 2,000 megawatts (MW) of bidirectional electricity, the equivalent of serving over 1.5 million homes, once energized.