Construction of the final segment of the Southwest Intertie Project, a 576-mile transmission corridor connecting an area from Idaho to just south of Las Vegas, Nevada, is underway. Officials celebrated the latest milestone for the installation during a groundbreaking ceremony in Ely, Nevada, on September 3.
LS Power, through its affiliate Great Basin Transmission, marked the start of work on the Southwest Intertie Project-North (SWIP-North) on Thursday. The SWIP-North, which is expected to enter operation in 2028, will be a 285-mile, 500-kilovolt (kV) transmission line connecting the Midpoint Substation near Twin Falls, Idaho, with the Robinson Summit Substation near Ely. LS Power said the project represents an investment of more than $1 billion in power infrastructure “that will help strengthen grid reliability, reduce congestion and expand access to diverse power supply resources across the West.”
“Reliable power increasingly depends on our ability to move electricity across regions, and that requires major investment in transmission,” said LS Power CEO Paul Segal. “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.”
Idaho to Southern Nevada
The entire Southwest Intertie Project once complete will connect Idaho’s Magic Valley to Nevada’s Eldorado Valley south of Las Vegas. The SWIP-North segment, more than 70% of which will be located in Nevada, joins two earlier phases of the overall project developed by LS Power. Those include the 231-mile One Nevada Transmission Line (ON Line), built in partnership with NV Energy and placed into service in 2014, and the 60-mile DesertLink Line, which began delivering power in 2020. The transmission paths connect to the California Independent System Operator (CAISO) grid.
NV Energy, Idaho Power, and CAISO all will share capacity rights on the line. The capacity agreement between NV Energy and LS Power affiliates stipulates that NV Energy covers all costs for the 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 CAISO and Idaho Power.
Mitch Colburn, Idaho Power vice president of Planning, Engineering and Construction, 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.”