Gateway West segment D stretches approximately 488 miles starting at the Windstar substation near Glenrock, Wyoming, proceeding south to Medicine Bow, Wyoming, and then spanning across southern Wyoming to the Populus substation near Downey, Idaho. This segment is sub-divided into three elements and when fully completed this segment will enable access to existing and new generating resources, including wind, delivering electricity from these sources to customers.
The Windstar-to-Populus transmission project consists of three key sub-segments:
The Energy Gateway West Subsegment D.1 project consists of a new 230 kV line and a rebuild of an existing 230 kV line between the Shirley Basin substation in southeastern Wyoming to the Windstar substation near Glenrock, Wyoming. Both transmission lines are currently under construction and scheduled to come online by the end of 2024.
The Populus-to-Hemingway transmission project consists of two single-circuit 500-kV lines that run approximately 500 miles between the Populus substation in eastern Idaho to the Hemingway substation in western Idaho.
The Gateway West Segment E project would enable PacifiCorp to more efficiently dispatch system resources, improve performance of the transmission system (i.e., reduce line losses), improve reliability, and enable access to a diverse range of new resource alternatives over the long term.
The estimated line in service for customers is 2030 at the earliest.
(Updated April 2023)