Mammoth Plains Energy Storage IIPlanned
Dewey County, Oklahoma · EIA plant ID 70443 · Operator: Mammoth Plains Energy Center, LLC
101 MW planned (Batteries), first expected May 2029 · EIA-860M
Nameplate—MWSummer — MW
Generators0in service
Net generation—GWh12 mo
Capacity factor—not meaningful for storage
Heat rate—thermal plants only
First online—
Capacity factor by year
Net MWh ÷ (summer MW × hours), primary-fuel units. Each year uses that year's EIA-860 ratings; the hollow dot is the latest 12 months.
No capacity factor available.
Heat rate by year
Electric fuel MMBtu × 1000 ÷ net MWh (Btu/kWh, HHV), fossil units only; CT + CA counted as one combined-cycle block.
Heat rate applies to fuel-burning (thermal) units only.
Generators
EIA-860 (annual) with EIA-860M updates through Sep 2026. EIA-923 reports generation by plant, prime mover and fuel, not by unit, so unit-level output isn't shown.
| Gen ID | Technology | Prime mover | Nameplate MW | Summer MW | Online | Status | Planned retirement | OEM / model |
|---|---|---|---|---|---|---|---|---|
| MAMM2 | Batteries | BA | 101.2 | 101.2 | planned May 2029 | Planned | — | coming soon |
Owner / operator
Operator: Mammoth Plains Energy Center, LLC. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
Nearby plants
Within 80 km.
| Mammoth Plains Energy Storage | — | 0.2 km |
| Mammoth Plains | 226 MW | 0.4 km |
| Crossroads Wind Farm | 228 MW | 6.3 km |
| Taloga Wind LLC | 130 MW | 27.4 km |
| Seiling Wind I | 199 MW | 30.2 km |
| Seiling Wind II | 99 MW | 30.2 km |