Springerville Generating Station Repower Project
About the project
SGS is operated by Tucson Electric Power (TEP), which owns units 1 and 2. TEP announced plans to convert units 1 and 2 to natural gas earlier this year and submitted an application to amend the CEC for these units in December 2025. On March 4, 2026, the Arizona Corporation Commission approved TEPs request to amend their existing CEC to allow their units to run on natural gas instead of coal as its fuel supply. Similarly, SRP submitted a request in May 2026 to amend our existing CEC to allow for the conversion of Unit 4 which was also approved by the ACC. Tri-State Generation and Transmission Association owns SGS Unit 3 and has not announced plans for the unit at this time. Each of these companies holds an individual Certificate of Environmental Compatibility for their respective units.
Arizona Corporation Commission Decision
On July 8, 2026, the Arizona Corporation Commission (ACC) approved the amendment to the Certificate of Environmental Compatibility (CEC) by a vote of 4-0.
Why is the project needed?
Converting the plant to run on natural gas is the lowest-cost option to preserve a firm capacity resource. This will be critical in meeting the peak energy demand of SRP customers, which is expected to increase by 50% from 2025 through 2035.
SRP reviewed the upfront investment and annual operating costs for potential alternatives through 2049. The conversion is expected to save $45 million compared to the cost of building a new natural gas facility. It is also expected to save approximately $826 million relative to adding new long-duration lithium-ion batteries over the same period.
This project is part of the Coal Communities Transition initiative in which SRP partners with Apache County to help implement a roadmap focused on entrepreneurship, tourism, site development, workforce development and community improvements.
Project timeline
SRP announced its intent to repurpose SGS from coal-powered to natural gas-powered. To support this effort, SRP plans to cease coal generation at the site and complete the conversion to natural gas by late 2029.
Past events
Apr. 14, 2026: Open House Meeting
SRP hosted an open house at the Round Valley High School Auditorium on April 14, 2026.
Sept. 14, 2023: Kiewit Repurposing Study and GAIN Repurposing Study presentation
The SRP Coal Communities Transition team presented the results of the Kiewit Repurposing Study and GAIN Repurposing Study.
Oct. 25, 2022: Coal community transition open house
With CGS set to cease coal generation no later than 2032, the SRP Coal Communities Transition team hosted an open house on Oct. 25, 2022, to discuss their efforts to help St. Johns and the surrounding communities develop sustainable and strategic economies. Attendees learned about current studies to determine the possibility of repurposing the site for other generation technologies.
The transition team also discussed the Arizona Commerce Authority’s $9.7M broadband grant, which SRP and TEP helped Apache County receive. Economic development consultants were also on hand to provide information to CGS employees about workforce development and job training opportunities in the area.
Contact us
If you have questions about the project, please call (602) 236-2872 or email [email protected].
