Phoenix, Ariz. —   During its annual Summer Preparedness Workshop on Thursday, April 24, 2025, the Arizona Corporation Commission heard presentations from electric utilities regarding their preparations for meeting summer peak demand.  

During Arizona Public Service Company’s (APS) presentation, Chairman Kevin Thompson and Vice Chairman Nick Myers raised concerns with the recent closure of the Cholla Power Plant (Cholla Plant) on March 17, 2025. Earlier this month, President Donald Trump called for the coal-fired plant to remain open and operational.  

In its response to Commissioner questions, APS stated that the process that culminated in closing the plant began ten years ago because of new regulations from the U.S. Environmental Protection Agency (EPA) making the operation of the plant uneconomic for their customers. APS added that because of the ongoing EPA regulations requiring new equipment for pollution control and significant deferred capital and maintenance investments that would have to be made, the re-opening and continued operation of the Cholla plant would come at a significantly high cost for customers. APS further stated that it plans to preserve the infrastructure of the Cholla Power Plant and offered it as a potential site for future nuclear power generation or natural gas-fired power generation. 

“We’re all aware of the detrimental loss of electric capacity with the closure of Arizona coal plants, and in part because of ongoing EPA regulations, it is a day late and a dollar short when it comes to re-opening the Cholla plant. Trying to re-open Cholla at this point would result in significantly higher rates for customers,” commented Vice Chair Myers, “The utilities have already been planning for this retirement and replacement costs are already being born by the utility customers. Re-opening Cholla would also require significant capital and maintenance investments that have been deferred. Further, the EPA requirements that made the continued operation of Cholla not cost-effective are still in effect. The damage has already been done, Arizona utilities are prepared for that and already planning to repurpose those plants for future generation, such as nuclear or natural gas-fired power.” 

“Bringing the Cholla plant into compliance with Obama era EPA requirements will require the installation of costly scrubbers on the coal-fired units that would cost ratepayers hundreds of millions of dollars,” said Chair Kevin Thompson. “The Commission must hold utilities accountable and ensure that we have reliable and dispatchable generation to meet the load demands of the future. We also have to make sure we accomplish that goal in a manner that doesn’t jeopardize the grid and burden ratepayers with millions of dollars in short-sighted costs that fail to meaningfully address our long-term energy needs.”

Tucson Electric Power (TEP) confirmed it is planning to retire Units 1 and 2 at their coal-fired Springerville Generating Station after the summer of 2027 and after the summer of 2032 respectively. TEP informed the Commission that the company plans to replace coal power with renewable energy and storage projects, but is exploring whether it can repurpose the Springerville plant for additional nuclear or gas generation.  

For more information, please contact Ryan Anderson at randerson@azcc.gov, or Amanda Hasty at ahasty@azcc.gov.