Great Basin Transmission, an affiliate of LS Power, has broken ground on the Southwest Intertie Project-North (SWIP-North), a 500 kV, 2 GW transmission line between Idaho and Nevada (United States) requiring a capital investment of more than USD1bn in power infrastructure (LS Power press release, 03/08/2026).
The project will link the Midpoint Substation in southern Idaho with the Robinson Summit Substation near Ely, Nevada (US). SWIP-North is expected to provide over 2 GW of bi-directional power transfer capacity, including 500 MW dedicated to Idaho Power customers.
The project is intended to complete the final segment of the Southwest Intertie Project, a transmission corridor originally envisioned in the 1980s. It will strengthen regional interconnections and facilitate power transfers between the Pacific Northwest and the Desert Southwest.
Over 70% of the SWIP-North route will run through Nevada. The new transmission line will connect to earlier phases developed by LS Power, namely the One Nevada Transmission Line, developed with NV Energy and operational since 2014, and the DesertLink segment, which has been in service since 2020.
In 2023, Great Basin Transmission was selected by the California ISO to develop, permit, finance, construct, own, operate and maintain the SWIP-North Project, with final cost recovery approval granted in 2024. Idaho Power received approval to participate in the project in 2025.
SWIP-North is expected to be completed in 2028.