Wilmot Energy Center II
Battery storage power plant · Pima County, Arizona
Nameplate capacity
200 MW
Rank in Arizona
#55
of 200 plants
In service since
2026
April 2026
Details
- Primary fuel
- Battery storage
- Technology
- Batteries
- Operator
- Wilmot Energy Center II, LLC
- County
- Pima County
- Generating units
- 2
- Share of state capacity
- 0.47%
- Rank among battery storage plants in Arizona
- #12 of 35
- EIA plant code
- 69254
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| WIL2B | Batteries | 100 MW | 100 MW | 2026 | Operating |
| WIL2S | Solar Photovoltaic | 100 MW | 100 MW | 2026 | Operating |
Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.
Similarly sized plants in Arizona
| Roadrunner Reserve Phase 1 | Battery storage | 200 MW |
| Westwing | Battery storage | 200 MW |
| McFarland C | Battery storage | 185 MW |
| Saguaro | Natural gas | 185 MW |
About this data
From EIA’s inventory of operable generators, May 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 200 MW solar plant and a 200 MW nuclear plant have the same entry here and produce very different amounts of electricity.
“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All Arizona power plants · What Arizona actually generates