Bonneville officials brief Senate committee on transmission capacity, queue growth and grid-enhancing technologies

Bonneville Power Administration officials told the Senate Environment, Energy & Technology Committee that transmission demand across the Pacific Northwest is rising rapidly and that the agency is accelerating projects and pilots to increase capacity and efficiency.

Melissa Skelton, a Bonneville Power Administration official, opened the committee work session by describing Bonneville as a federal power-marketing administration within the U.S. Department of Energy that moves and sells power produced at federal hydroelectric sites and other generators. "We do recover all of our costs from selling power and transmission," Skelton said.

Why it matters: Committee members heard that Washington’s ability to deploy renewable generators, serve growing industrial and data‑center loads, and keep the grid reliable depends on major transmission work — both new lines and upgrades to existing corridors. Bonneville officials warned the committee that interconnection and transmission service requests have grown sharply and that the utility must scale capital delivery to meet customer needs.

Bonneville details and capacity drivers

Kevlyn Baker, manager of the customer service engineering organization at BPA, described how BPA plans and studies the transmission system. "BPA's transmission plan is produced yearly...the planning process is conducted in an open, coordinated and transparent manner," she said, adding that planning uses comprehensive system modeling and a 10‑year planning horizon.

Skelton told the committee that Bonneville owns and operates more than 15,000 miles of transmission lines and sells roughly 80% hydroelectric power into the region. She said Bonneville accounts for about 28% of power in the Pacific Northwest and about 50% of power in Washington state.

Interconnection and queue reform

Baker said BPA operates three separate queues — generation interconnection, transmission service requests and line/load interconnection — and reported exponential growth in interconnection volume since 2017. She noted a specific procedural change: on Jan. 26, 2024, BPA moved from a serial first‑in, first‑out large‑generation queue to a first‑ready, first‑served cluster process. "Over 200 requests were received for that transition late last year, and that represents almost 100 gigawatts that will be going into our new transition cluster study," she said.

The committee asked for clarification about the queue change. Baker explained that "first in, first out" prioritized requests by timestamp while "first ready, first served" treats cluster applicants equally and advances those that are commercially ready — for example, with site control or power‑purchase agreements.

Evolving Grid and capital needs

Skelton described the Evolving Grid initiative, a multi‑project program that Bonneville has expanded to 23 proposed projects, with a preliminary cost estimate of about $5,000,000,000. She said the work includes proactive main‑grid reinforcements intended to increase capacity and reliability across load centers in the Northwest. The agency reported a recent year in which it deployed $665,000,000 toward capital projects — a rise of $232,000,000 over the prior year — and said it expects to need materially greater capital execution through 2028.

Grid‑enhancing technologies and pilots

Baker explained grid‑enhancing technologies (GETs) and examples Bonneville is piloting: advanced conductors and dynamic line ratings (DLR). Advanced conductors (various aluminum conductor composite or steel‑supported types) can allow reconductoring that increases capacity while staying within existing tower loading constraints. Baker cited John Day powerhouse‑to‑John Day substation reconductoring and a proposal for Big Eddy–Ostrander as examples where advanced conductors were used or proposed.

On dynamic line ratings, Baker said DLR systems update line capacity using monitored weather and conductor conditions rather than static assumptions. "The DLR can be difficult to use accurately because wind speed can be very variable, and it can also be very localized based on terrain," she said.

Committee concerns and follow up

Committee members asked about wildfire risk, coordination with the Department of Natural Resources (DNR), and possible federal funding changes. Skelton said Bonneville has teams that coordinate with DNR on wildfire issues and that the agency is still assessing the implications of recent federal hiring or funding decisions. "Bonneville is still examining at this point what the results of these mean," she said regarding federal actions.

Members also pressed Bonneville about regional changes as more intermittent solar and wind resources come online. Skelton said interconnection and transmission service requests from renewable projects flow through the same planning and queue processes and offered to provide follow‑up materials with specifics.

Ending

Bonneville officials offered to provide additional slides and follow‑up information to committee members on reconductoring gains, planned Evolving Grid projects in Washington (including Cross Cascade North, Chehalis–Covington and Grand Coulee–Columbia–Schultz segments) and the agency’s wildfire coordination work.