PacifiCorp plans to build a new 60-mile 345 kilovolt single-circuit transmission line between the existing Three Peaks substation near Cedar City, Utah, to the existing Purgatory Flat substation near Washington, Utah. The new transmission line will provide additional capacity to help serve growing customer needs in Utah while increasing overall system reliability. This line will deliver electricity generated from PacifiCorp’s generating resources, including renewables and thermal resources, while adding the benefits of increased reliability and capacity.
The purpose and need for the Three Peaks to Purgatory 345 kV line is to ensure the transmission system is reliable. The significant growth that Southern Utah has experienced has increased the demand for energy, and that demand continues to rise. There has also been an increase in solar power development in southern Utah and this new line is needed to economically meet reliability requirements and transport resources across the service area. Without a new line, if an outage is experienced, the area’s transmission system would not meet reliability planning standards. The line will strengthen resiliency and optimize the capability of the transmission network to support renewable and other energy resources.
The project is in the planning stages. PacifiCorp is conducting a routing study and meeting with local agencies to gather information in efforts to identify a suitable route. Route selection takes into consideration impact on existing land uses, biological and environmental factors, known resource constraints and feasibility. Considering these factors, certain route options have been eliminated from further consideration.
Three Peaks to Purgatory Flat Project Map
Reliability
Economic development
Increased resilience from extreme event or wildfire
Public outreach | 2025-2026 |
Permitting | 2027-2029 |
Engineering | 2027-2029 |
Rights-of-Way | 2028-2030 |
Construction | 2030-2032 |
In-service | August 2032 |