The Wyoming Public Service Commission granted PacifiCorp certificates of public convenience and necessity (CPCNs) May 10, allowing two important transmission lines to proceed with construction. The approval was granted in the Wyoming commission’s open deliberation and will be followed by a written order. The Public Service Commission of Utah granted a similar approval April 8.
The Gateway South high-voltage transmission line segment, part of PacifiCorp’s Energy Gateway transmission expansion project, will extend approximately 400 miles from the Aeolus Substation near Medicine Bow, Wyoming, into the Clover Substation near Mona, Utah. Also receiving approval was Segment D.1 of the Gateway West line, which runs approximately 75 miles between the existing Windstar substation in eastern Wyoming and the Aeolus substation. Both transmission additions are planned to be in-service in late 2024. Construction is anticipated to begin in early June for Gateway South and in August for Segment D.1.
The new lines will deliver several key benefits to serve growing customer needs across all six states served by PacifiCorp: enabling the interconnection and integration of new renewable resources; more efficient and reliable use of existing generation resources; and ensuring compliance with reliability and network performance standards governed by the North American Electric Reliability Corporation and the Western Electricity Coordinating Council.
“These investments also support Wyoming’s energy policy by increasing the reliability of the Wyoming transmission network,” said Gary Hoogeveen, president and CEO of Rocky Mountain Power, PacifiCorp’s retail service division in Utah, Wyoming and Idaho. “Transmission additions allow the interconnection of the additional generation resources our customers will need in the coming years—including the evaluation of potential carbon-capture projects that Wyoming officials have requested; and pursuing advanced nuclear and energy storage with TerraPower, among other technologies in our diversified clean energy strategy.”
“This is a major step forward in our work toward an expanded, modernized grid that will integrate diverse, abundant resources across the West to advance an affordable and reliable clean energy future that our customers demand,” said Stefan Bird, president and CEO of Pacific Power, PacifiCorp’s retail service division in Oregon, Washington and California. “These additions provide benefits to PacifiCorp’s entire six-state service area, strengthen the regional grid and decrease the reliance on wholesale power purchases, creating a more secure and reliable electric generation and transmission system.”
PacifiCorp’s updated economic analysis confirms that the Gateway South transmission projects are necessary and expected to provide significant customer benefits. The company’s 2021 Integrated Resource Plan shows that customers will need additional generation capacity in all years of the 20-year planning horizon. In 2021, the capacity need was over 1,000 megawatts and increases over time to more than 6,600 megawatts by 2040. In 2025, the first full year that the transmission projects will be online, the capacity need is expected to be 1,627 megawatts. Over the current 20-year planning horizon, the resource portfolio that includes the Gateway South and Gateway West segments is $260 million lower in cost than the comparable portfolio without the projects.