USA, Arizona, Navajo County: Arizona Public Service plans to convert two retired coal units at the Cholla Power Plant in Navajo County, Arizona, to natural gas generation.
The conversion is expected to add up to 380 MW of dispatchable capacity, helping APS meet rising electricity demand in Arizona. Construction is planned to begin in 2028, with the new gas facility targeted to enter service in 2029.
Cholla’s coal units were retired over the past decade in response to federal environmental requirements, with the final unit retired in March 2025. At peak output, the plant previously supplied around 1 GW of power.
APS said earlier assessments of a possible gas conversion did not show sufficient economic benefit for customers. However, the utility said Arizona’s growing need for around-the-clock energy, combined with the long timelines required to add new generation, has made the conversion a viable option.
The project will also use existing transmission lines and other infrastructure at the site, supporting faster and more cost-effective integration than building entirely new generation facilities.
APS expects electricity sales to grow by 4 % to 6 % annually through 2027, driven largely by large new loads on its system. The Arizona Corporation Commission has said APS estimates peak demand from large customers could reach about 13.1 GW this year.
“Cholla has been an important part of the communities of Joseph City, Holbrook, Navajo County and northeastern Arizona for decades and has been foundational to Arizona’s energy grid,” said Johnny Penrod, APS vice president of generation. “Repurposing the Cholla Power Plant for natural gas allows us to build on that legacy.”
The project will still require formal permitting and planning processes, including public engagement.
Source: Utility Dive
