SWIP-North 500-kV Transmission Line — Ely, Nevada

LS Power affiliate Great Basin Transmission is building a 285-mile, 500-kV line between Idaho and southern Nevada, closing the last unbuilt gap in a high-voltage corridor first conceived in the 1980s. Construction started Sept. 3, 2026 with a groundbreaking in Ely, Nevada, attended by Gov. Joe Lombardo.

Project Scope

The Southwest Intertie Project-North, or SWIP-North, runs 285 miles of single-circuit 500-kV line from Idaho’s Magic Valley south through eastern Nevada. Combined with two existing lines through the state, the completed 576-mile corridor carries roughly 2,000 MW in either direction. CAISO put the capital cost at $1.23 billion in November 2024, excluding construction financing.

Federal authorization for the corridor dates to 1994. LS Power acquired development rights in 2005. The U.S. Energy Dept. committed up to $331 million in capacity support in 2024, providing a temporary backstop while Idaho Power worked out its participation in the line.

Why It Matters

SWIP-North is one of the few long-haul Western transmission projects where two buyers want the same wires for opposite reasons. California grid planners advanced the project to import Idaho wind generation moving south. Idaho Power secured 500 MW moving north out of Desert Southwest markets to meet load growth at home. That bidirectional use is what finally produced enough contracted capacity to finance a line that had sat dormant for decades.

For the Western Interconnection, the project adds transfer capability between the Pacific Northwest and the Desert Southwest at a moment when data center load and electrification are straining regional resource adequacy. It is also a test of whether merchant transmission development can work in the West without a single utility owner driving it. LS Power carried the project for two decades on that bet.

Construction sequencing on a line this long is mostly access and logistics. Crews build and improve spur roads, set foundations, assemble and fly steel lattice structures by helicopter across the roughest spans, then pull conductor in segments. Federal land crossings bring seasonal wildlife and cultural resource windows that shape when work can happen more than weather does.

Project Team & Details