Great Basin Transmission Breaks Ground on Southwest Intertie Project-North

New 285-mile, 500 kV transmission line will link Idaho and Nevada, strengthen grid reliability, reduce congestion and open new energy pathways across the West

ELY, Nev., Sept. 3, 2026 /PRNewswire/ -- LS Power, through its affiliate Great Basin Transmission, will hold a groundbreaking ceremony today in Ely, Nevada, officially marking the start of construction on the Southwest Intertie Project-North (SWIP-North), a new 285-mile, 500 kilovolt (kV) transmission line connecting the Midpoint Substation near Twin Falls, Idaho, with the Robinson Summit Substation near Ely, Nevada. The project represents a $1 billion-plus investment in power infrastructure that will help strengthen grid reliability, reduce congestion and expand access to diverse power supply resources across the West.

LS Power CEO Paul Segal said, "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. Projects of this scale take persistence, and we're proud to have spent more than two decades advancing this corridor to construction."

Background
SWIP-North is the final segment of the Southwest Intertie Project — a transmission corridor first conceived in the 1980s and advanced by LS Power since it acquired development rights in 2005. Once complete, 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 built in Nevada. Once in service, it will complete a high-voltage transmission corridor stretching from southern Idaho to southern Nevada, building 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).

Nevada Governor Joe Lombardo said, "Construction of this last phase of the Southwest Intertie Project underscores Nevada's position as a strategic energy hub for the West. SWIP-North will provide benefits for Nevadans, 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."

Project Details
Once SWIP-North is energized, the full transmission path will be capable of transmitting more than 2,000 megawatts (MW) of bidirectional electricity — the equivalent of serving over 1.5 million homes — across the regional grid, including 500 MW of northbound capacity dedicated for Idaho Power customers.

LS Power President Paul Thessen said, "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."

Specifically, the California ISO, NV Energy and Idaho Power will all share capacity rights on the line. This stems from an agreement between NV Energy and LS Power affiliates whereby NV Energy covers all costs for ON Line; LS Power covers all costs for SWIP-North; and both share capacity across the full path. LS Power has assigned its capacity rights to the California ISO and Idaho Power.

California ISO President and CEO Elliot Mainzer said, "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."

Idaho Power Vice President of Planning, Engineering and Construction Mitch Colburn 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."

Timeline and Benefits
Construction on SWIP-North began in summer 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.

LS Power Senior Vice President of Development Mark Milburn added, "Beyond the increased electrical capacity that the project will bring to the Western grid, SWIP-North will bring measurable economic benefits to Nevada and Idaho during construction and beyond. 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."

About Great Basin Transmission 
Great Basin Transmission is an electric transmission utility in Idaho and Nevada that provides stability and reliability for the electric grid in the western United States.

About LS Power
Founded in 1990, LS Power is a premier development, investment, and operating company focused on the North American power and energy infrastructure sector, with leading platforms across generation, transmission and energy transition solutions. Through its transmission business, LS Power Grid, the company has built 780+ miles of high-voltage transmission systems with another 400+ miles in development. For more information about the company's transmission business, please visit lspowergrid.com.

Media Contacts
On behalf of Great Basin Transmission, contact [email protected].
Contact LS Power at [email protected].

SOURCE LS Power