Arizona's power story runs through a large gas fleet, a major nuclear base, a steep coal decline, and one of the West's fastest recent battery-storage buildouts.
The lead chart shows a state still anchored by gas and nuclear, but with coal sharply reduced and solar no longer marginal. The key question is what kind of replacement system Arizona is actually building: cleaner, more gas-heavy, or mixed.
In 2025, gas still generated the biggest share of Arizona's utility-scale power. Nuclear remained the second-largest source, solar had grown well above coal, and coal itself accounted for less than one-tenth of the state's utility-scale generation.
Arizona's mix still depends heavily on gas and Palo Verde nuclear, even as coal loses ground and solar plus storage grow into a much bigger part of the system.
Gas leads the system, nuclear remains large, solar is growing fast, and coal has been pushed into a much smaller role than it held a decade ago.
Arizona is one of the clearest Western examples of long-run coal decline. That shift now has to be read alongside the state's gas fleet, its large Palo Verde nuclear base, and the speed of solar and storage additions.
Arizona's coal story is not finished. The operating workbook still shows three remaining coal plants, but the timing differs by unit and the local project notes suggest Springerville and Coronado are part of Arizona's coal-to-gas transition story rather than simple long-life coal holdouts.
| Plant | Coal MW | EIA retirement timing | Transition context |
|---|---|---|---|
| Springerville | 1,765.8 MW | Unit 1 shows December 2027; Unit 2 shows December 2032; Units 3 and 4 show no retirement timing in the May 2026 operating sheet. | Tracked separately in project notes as a coal-to-gas conversion that depends on gas pipeline availability by 2029, enabling gas firing in 2030. |
| Coronado | 821.8 MW | Both operating coal units show planned retirement in December 2032 in the May 2026 operating sheet. | Tracked separately in project notes as a coal-to-gas conversion framed around 2029. |
| Apache Station | 204.0 MW | No planned retirement timing appears in the May 2026 operating sheet. | The current local notes do not show the same coal-to-gas conversion context here as they do for Springerville and Coronado. |
If coal decline is one side of the Arizona story, battery storage is one of the clearest signs of what the replacement system is becoming. The May 2026 generator workbook shows a state that moved from niche battery capacity to utility-scale deployment very quickly.
Through April, Arizona is using less coal and more solar than it did at the same point last year. Gas is still carrying the largest block of generation, so the current-year transition is moving in more than one direction at once.
| Project | Technology | Capacity | Status | Timing | Why it matters |
|---|---|---|---|---|---|
| Roadrunner Solar and BESS | Battery storage | 235 MW | Operating | January 2026 | Already visible in the operating sheet, which makes it one of the clearest live 2026 additions. |
| West Camp Wind Farm | Wind | 500 MW | Operating | April 2026 | Moved into the May 2026 operating sheet, making it one of Arizona's largest live 2026 additions. |
| Atlas | Solar + battery | 300 MW solar + 300 MW battery | Under construction | July 2026 planned | A high-signal example of Arizona's utility-scale solar-plus-storage buildout. |
| Beehive Energy Storage | Battery storage | 250 MW | Operating | April 2026 | Now visible in the May 2026 operating sheet, showing how quickly late-stage storage is becoming live capacity. |
| Flatland Storage | Battery storage | 200 MW | Operating | December 2025 | Now reflected in the May 2026 operating sheet, which also backfills the 2025 operating total. |
These projects help explain how Arizona may replace coal and how the next phase of solar, gas, wind, and storage additions could change the state mix.
| Project | Technology | Status | Capacity | Timing | Why it matters |
|---|---|---|---|---|---|
| Springerville coal-to-gas conversion | Coal to gas conversion | Tracked | TBD on page | Gas firing targeted around 2030 | High-value transition case for Arizona's replacement story. |
| Coronado coal-to-gas conversion | Coal to gas conversion | Tracked | TBD on page | Conversion framed around 2029 | Important for understanding whether coal exits cleanly or shifts to gas. |
| Arizona solar and storage additions | Solar and storage | To curate | TBD from EIA and reviewed sources | Near-term pipeline | Use a few named additions to keep the first page concrete. |
EIA and Supabase provide the structured baseline, with curated project context added only where it clarifies the state story without double counting.
Related reporting and background context from Mission City Research.
Open articleRelated reporting and background context from Mission City Research.
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