Energy Gateway Transmission Map

Energy Gateway transmission map (for general reference, March 2021).

PacifiCorp has been given the final regulatory green light to begin construction on two segments of its $8 billion Energy Gateway transmission project.

The Wyoming Public Service Commission on May 10 granted certificates of public convenience and necessity, which followed on the heels of approvals from the Utah PSC on April 8.

The orders allow construction to begin on a 400-mile section of the Gateway South segment, stretching from near Medicine Bow, Wyo., to Mona, Utah, and also cover a 75-mile section of the D.1 segment of the Gateway West line in eastern Wyoming.

Construction is anticipated to begin in early June for Gateway South and in August for Segment D.1. Both transmission additions are planned to be in service by late 2024.

PacifiCorp says the Energy Gateway project will help it access renewable energy generated in the Intermountain West and deliver it to cities in the West.

The 2,000-mile project is the largest transmission expansion project currently in development in the Western U.S.

Since development begin in 2007—and through the 2008 economic meltdown and the recent pandemic—PacifiCorp has completed 525 miles of the project at a cost of $2.4 billion, the utility told Clearing Up.

"These investments to expand and modernize our grid are the foundation of our plan to deliver our customers' demand for a transition to a clean energy future that is affordable and reliable," Stefan Bird, president and CEO of PacifiCorp, said in an email to Clearing Up.

"It enables access to the West's abundant and diverse energy resources and is also foundational to enabling advanced energy markets including the Western Energy Imbalance Market and a future day-ahead market which will provide lower costs for customers, reduce emissions and improve reliability and resilience."

The first major segment of the project—a 345 kV line that runs 135 miles from Populus substation in southeast Idaho to Terminal substation in northern Utah, part of the Gateway Central section—was placed into service in November 2010.

In May 2013, a 100-mile section of 500 kV and 345 kV line, running from Mona to Oquirrh in Utah, was placed into service.

A 170-mile, 345 kV line running from Sigurd to Red Butte in Utah was completed in May 2015 and a 30-mile, 230 kV line from Wallula to McNary in Washington was finished in 2019.

PacifiCorp announced in November 2020 that it had energized a 140-mile section of the Gateway West segment that stretches from a newly built Aeolus substation near Medicine Bow, Wyo., to the Anticline and Jim Bridger substations near Rock Springs, Wyo.

PacifiCorp is still working on the remaining 1,481 miles of the project, but 475 miles have received permits from Utah and Wyoming regulators. The 400-mile, 500 kV Aeolus to Clover line (Segment F), which is part of the Gateway South segment, is anticipated to be completed in 2024. A 75-mile piece of the Gateway West portion of the project, running from Windstar to Aeolus, is also expected to be on line in 2024.

The proposed $1.2 billion Boardman to Hemmingway transmission project would be the final piece of Energy Gateway, connecting it with Mid-C trading operations. It is expected to have all permits and approvals in hand by the end of this year, with construction starting in 2023, a spokesman for Idaho Power told Clearing Up. Idaho Power and PacifiCorp are partners on the B2H project.

The B2H project is anticipated to go live by June 1, 2026.

PacifiCorp's 2021 integrated resource plan shows the need for 1,345 MW of new wind and solar generation resources, combined with 600 MW of co-located energy storage resources within the next six years. The company released an all-source request for proposals on April 29 (CU No. 2054 [7]).

The utility is still reviewing a shortlist of 3,250 MW of solar, wind and battery storage projects—mostly in Wyoming, Utah and Oregon—that were culled from a 2020 RFP. Those projects could be on line in 2024.

In August 2021, PacifiCorp closed the books on its $3.1 billion capital investment plan, known as Energy Vision 2020, that doubled its wind production and included the 140 miles of the Gateway West line in Wyoming.

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Editor - Clearing Up

Steve began covering energy policy and resource development in the Pacific Northwest in 1999. He has been editor of Clearing Up since 2003, and has been a fellow at the Institute for Journalism and Natural Resources and University of Texas.