APS's Cholla Gambit: Why Natural Gas is the New King in Arizona's Grid

JOSEPH CITY, AZ – July 02, 2026 – In a decisive maneuver signaling a major strategic pivot, Arizona Public Service (APS) has announced it will resurrect a portion of its recently shuttered Cholla Power Plant, converting two of the site’s coal-fired units to burn natural gas. The move transforms a relic of Arizona’s 20th-century industrial backbone into a critical asset for its 21st-century growth spurt, leveraging existing infrastructure to secure grid stability in one of America's fastest-growing states.

The project, slated to come online in 2029, represents more than just a fuel switch. It's a high-stakes bet on the role of natural gas as the indispensable partner to renewable energy and a calculated response to the immense pressure on Arizona's power grid. For parent company Pinnacle West Capital Corp. (NYSE: PNW), this repowering project is a tangible signal of its strategy to navigate the complex energy transition while meeting soaring demand.

An Economic Lifeline for Navajo County?

For decades, the Cholla Power Plant was the economic heart of Joseph City and a major contributor to the tax base of surrounding Navajo County. The phased retirement of its coal units, culminating in the final shutdown in March 2025, left a significant void. The closure was an expected outcome of federal environmental mandates and a national shift away from coal, but it hit the local community hard, threatening jobs, school funding, and economic stability. APS's announcement to reinvest in the site is being hailed by local officials as a much-needed reversal of fortune.

“I could not be more excited by this announcement," stated Navajo County Supervisor Jason Whiting, a vocal advocate for the plant's conversion. "APS's decision to convert Cholla into a natural gas plant will strengthen our local economy, create jobs and support our schools. Even more importantly, it will help power our state with reliable, affordable energy.”

The project promises hundreds of temporary construction jobs starting in 2028 and, more crucially, several dozen permanent, high-skilled positions to operate the new gas-fired units. For a region grappling with the economic aftermath of coal's decline, this represents a significant lifeline. The projected 380-megawatt output, enough to power over 60,000 homes, ensures the plant remains a key piece of state infrastructure, anchoring its economic relevance.

“Losing the plant felt like the ground fell out from under us,” said one local business owner. “This new investment isn’t just about the direct jobs at the facility; it’s about the tax revenue that keeps our public services running and the confidence it gives everyone that this community has a future.” The conversion leverages the plant's most valuable assets beyond its turbines: the high-voltage transmission lines that connect this remote corner of Arizona to the state's major load centers. Building such infrastructure from scratch would be prohibitively expensive and time-consuming.

The Strategic Imperative of Dispatchable Power

Beyond the local economic impact, the Cholla conversion is a masterclass in corporate strategy, reflecting a stark reality facing utilities across the Southwest. Arizona’s population and industrial base are expanding at a blistering pace, with APS projecting peak energy demand could surge by 40% by 2031. This growth coincides with the retirement of legacy coal plants like Cholla and the planned 2031 exit from the Four Corners Power Plant, removing thousands of megawatts of consistent, around-the-clock power from the grid.

While APS is aggressively pursuing its goal of a 45% renewable energy mix by 2030 and 100% clean energy by 2050, solar and wind power are intermittent. The sun doesn't shine at night, and the wind doesn't always blow when demand peaks. This is where natural gas comes in. As a dispatchable resource, gas-fired turbines can be fired up in minutes to fill generation gaps, stabilize the grid, and prevent blackouts—a role that batteries are beginning to fill but cannot yet sustain for long durations at scale.

APS's 2023 Integrated Resource Plan (IRP) explicitly highlighted the urgent need for new dispatchable resources to ensure reliability. The Cholla conversion directly answers that call. “This isn’t just about adding 380 megawatts; it's about adding 380 megawatts of flexible, on-demand power exactly where it’s needed,” commented an independent energy analyst. “APS is using an existing brownfield site and transmission corridor to add a critical balancing tool to their portfolio. It’s a pragmatic, if not universally popular, solution to a very real engineering and economic problem.”

By repurposing Cholla, APS avoids the lengthy and often contentious process of siting a new power plant and transmission lines, making it a cost-effective and efficient move to bolster its generation fleet, which also includes the nation's largest nuclear power producer, the Palo Verde Generating Station.

A Legacy Repurposed, A Future Debated

The Cholla plant's story is a microcosm of America's energy transition. Commissioned in 1962, it powered Arizona's rise for over 60 years. Its towering stacks were a symbol of industrial might, but also a source of pollutants that led to its eventual obsolescence under stricter federal environmental rules. Now, the site itself is being recycled. However, the pivot to natural gas is not without controversy.

While significantly cleaner than coal—emitting roughly half the carbon dioxide and drastically fewer pollutants like sulfur dioxide and particulate matter—natural gas is still a fossil fuel. Environmental advocates raise valid concerns about methane leaks from the natural gas supply chain, as methane is a far more potent greenhouse gas than CO2 in the short term. The decision locks in fossil fuel infrastructure for decades at a time when the climate crisis demands a faster transition to zero-emission sources.

The path to operation is also not guaranteed. The project must clear a series of formal permitting and planning processes, most notably securing a Certificate of Environmental Compatibility from the Arizona Corporation Commission (ACC). This same regulatory body rejected a 2019 APS proposal to convert a Cholla unit to burn biomass, demonstrating that approval is not a foregone conclusion. Furthermore, the site has a history of industrial contamination, having been part of the Arizona Department of Environmental Quality's Voluntary Remediation Program since 1998 for soil and groundwater contamination, requiring ongoing monitoring.

APS appears ready for the scrutiny, planning extensive community outreach as it moves toward a 2028 construction start. The Cholla conversion thus stands as a powerful symbol of the trade-offs at the heart of the modern energy landscape: balancing economic stability, grid reliability, and environmental responsibility on the long road to a clean energy future.