APS converts Cholla coal plant to gas, adds 380 MW
Get the Energy newsletter
Daily energy & climate — solar, EVs, oil, the policy fights and tech bets shaping the transition. Free.
- Arizona Public Service plans to convert two units at the retired Cholla Power Plant in Navajo County to natural gas generation, adding up to 380 MW of capacity.
- The Cholla plant's coal units were retired over the past decade under federal environmental mandates, with the final unit shut down in March 2025; at peak the facility supplied roughly 1 GW.
- APS said Arizona's rising around-the-clock energy demand and long timelines for new generation now make the conversion economically viable, reversing earlier evaluations that found no customer benefit.
- The utility projects electric sales growth of 4-6% annually through 2027, and the Arizona Corporation Commission said APS estimates peak demand from large customers will reach approximately 13.1 GW this year.
- Johnny Penrod, APS vice president of generation, said Cholla has been foundational to Arizona's grid and that repurposing it honors its legacy in Joseph City, Holbrook, and Navajo County.
- Construction is slated to begin in 2028 with a target in-service date of 2029, pending formal permitting, planning, and public comment through open houses and written input.
Why it matters: APS is chasing projected 4-6% annual sales growth and roughly 13.1 GW in large-customer peak demand by retrofitting existing Cholla infrastructure rather than building greenfield — converting retired coal to gas is cheaper and faster, putting 380 MW online by 2029 without new transmission or siting.
