Power Conversion

Arizona plant announces switch to natural gas

Arizona Public Service (APS) announced July 2 that it plans to convert two units at its Cholla Power Plant in Joseph City, Navajo County, Arizona to natural gas.

The repurposed resource, with operations beginning in 2029, "will help meet the state’s growing energy demand while maintaining reliable, affordable electric service for customers," the utility said in a July 2 press release.

Originally commissioned in 1962, the Cholla Power Plant played a vital role in powering Arizona for decades, providing a critical power supply to the state. Beginning in the last decade, federal environmental mandates forced the phased retirement of the plant’s coal units, completed in March 2025. APS plans to convert two units at the site to natural gas, preserving its legacy in the state while leveraging existing transmission lines and infrastructure to support Arizona’s energy future.

“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 – supporting reliable, affordable energy for our customers while continuing to invest in the communities who have long supported this plant.”