Idaho-Nevada Line Breaks 30-Year Stall, But Questions About Capacity, Cost, and Landowner Terms Remain

LS Power's affiliate Great Basin Transmission broke ground on the Southwest Intertie Project-North (SWIP-North) in September 2026 in Ely, Nevada, marking the formal start of construction on what may be the first major interregional transmission line to reach actual fieldwork in years.^[1][2] The 285-mile, 500-kilovolt line will connect the Midpoint Substation near Twin Falls, Idaho, with the Robinson Summit Substation near Ely, Nevada, and is expected to open by 2028.^[1] The project cost exceeds $1 billion and will deliver bidirectional capacity of 2,000 megawatts once it integrates with existing segments of the Southwest Intertie Project.^[1][4] California's grid operator (CAISO) selected Great Basin Transmission to develop, permit, finance, and own the line, and Idaho Power has signed an agreement to import 500 megawatts of capacity into Idaho during peak demand periods.^[5][7] On the surface, this appears to be what transmission development should look like: a regional bottleneck identified, a developer selected through a planning process, and a utility committing to use the capacity for customer benefit. But the three-decade journey to construction and the underlying financing structure reveal the structural incentive that makes transmission development so slow and expensive.

Start with the need. The line fills a genuine gap: California grid operators have for years sought interregional capacity to bring Idaho wind and hydropower south during high-demand periods, while Idaho Power has committed to importing low-cost Southwest generation during winter months, reducing heating costs for its customers.^[1][7] That dual directionality itself is evidence that the line serves multiple legitimate demand centers, not a single incumbent's self-dealing. But the 30-year permitting clock raises an unavoidable question: why did a project addressing real grid needs sit in development longer than most engineers spend in careers? The answer is not primarily technology or environmental challenge, SWIP-North is a 500-kV line on a well-mapped route through Nevada, not a novel problem. The delay reflects instead the structural economics of transmission ownership. For decades, the transmission owner earned no return during permitting; only upon construction and rate-basing would the capital start generating FERC-regulated return. LS Power's interest in accelerating construction was muted by default. CAISO's selection of Great Basin as developer in 2023 and its final approval in 2024 changed that calculus by anchoring demand and committing capital.^[5] That sequence is useful: an independent grid operator with statutory authority to procure transmission capacity can overcome the incumbent-development inertia that would have left SWIP-North stranded another decade.

The critical question now is whether the executed project represents the lowest-cost way to move that capacity. The bundle does not disclose whether Great Basin Transmission, LS Power, or either customer (CAISO or Idaho Power) conducted a formal grid-enhancing technologies (GET) screening against the $1 billion investment. Dynamic line rating studies on the existing legs of the Southwest Intertie might have revealed spare thermal capacity; advanced power-flow control or topology optimization could have routed flows around bottlenecks without new wire; advanced reconductoring on existing towers could have doubled capacity of congested segments without new rights-of-way; or storage sited near load could have replaced transmission for winter peak mitigation in Idaho.^[2] None of those alternatives appears in the public record or project materials. This is not necessarily a failure on the developers' part, CAISO's planning process may have screened them, but it is a gap in public accountability. A $1 billion transmission project should disclose what non-wires alternatives were considered, whether they were cost-effective, and if not, why not, on the record. The absence of that disclosure does not prove that SWIP-North is gold-plating, but it means the public cannot verify that it isn't.

The second order issue is cost allocation and what Great Basin Transmission will be paid to operate the line. FERC Order 1920 and its successors require regions to allocate long-term transmission costs based on defined benefits, production-cost savings, reliability, resilience, avoided-cost, capacity.^[4] The allocation determines whether California pays, Idaho pays, both split costs, or ratepayers across the broader interconnect absorb the project as a reliability good. The sources do not disclose the allocation method CAISO, Idaho Power, and Great Basin agreed on, whether it went through a FERC-filed regional cost-allocation process, or what the capital cost per megawatt-mile and the annual operating return will be. This matters because a $1 billion, 285-mile, 2,000-megawatt line represents an opportunity cost: that capital could be deployed to other transmission corridors, storage, or non-wires solutions elsewhere on the grid. If CAISO and Idaho Power are cross-subsidizing Great Basin Transmission's return through an allocation that misrepresents the project's true benefits, the capital is misallocated and ratepayers in both states lose. The fact that the line addresses real need does not mean the price is efficient.

The third, least visible factor is the question of landowner terms. SWIP-North runs 285 miles, mostly through Nevada, and will require easements across private land, tribal lands, and BLM rights-of-way.^[1][4] LS Power has not disclosed the landowner compensation structure: Are affected parties receiving annual payments indexed to inflation, or one-time lump sums? Are neighboring properties receiving community benefit agreements, or bare-minimum regulatory compliance? Are small farmers and ranchers represented in the project's community engagement, or did they learn about right-of-way entries from a certified letter? The sources make no mention of these terms. Given that transmission development depends on landowner consent and that many rural objections to proposed lines stem from inadequate compensation and exclusion from planning, the absence of disclosed terms is a red flag. A transmission developer confident in its landowner relationships should publish them. The fact that Great Basin Transmission has not, despite completing 30 years of permitting, suggests either that negotiations remain hostile or that the developer sees no incentive to set a high bar for future projects in the region.

Set against this, SWIP-North's merits are real and its approval legitimate. The Western grid is capacity-constrained at critical interregional points; California's renewable transition depends on accessing wind and hydro from the Northwest and Southwest; Idaho's winter load-relief depends on access to Southwest market pricing; and a line that enables those flows without requiring each region to build redundant local generation is genuinely economically sound. The question is not whether the line should be built, but whether its terms, cost allocation, and landowner relationships represent an efficient, sustainable model for how transmission development should work going forward. On that measure, the evidence in the public record is incomplete. SWIP-North appears poised to become a case study in how a long-delayed project finally breaks through, and whether it did so by solving the right problems or by accepting the inefficiencies that delayed it in the first place.