Mammoth Pacific II
Mono County, California · EIA plant ID 10481 · Operator: Ormat Nevada Inc
Nameplate15MWSummer 10 MW
Generators3in service
Net generation84GWh12 mo to Dec 2025
Capacity factor97%geothermal units, summer MW
Heat rate—thermal plants only
First online1990
Monthly net generation
EIA-923, all units at the plant. Net of station use; storage can go negative.
FinalPreliminary
Capacity factor by year
Net MWh ÷ (summer MW × hours), geothermal units. Each year uses that year's EIA-860 ratings; the hollow dot is the latest 12 months.
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.
Annual data table
| Year | Net GWh | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|
| 2001 | 82.1 | 74.4% | — |
| 2002 | 81 | 73.4% | — |
| 2003 | 76.6 | 69.4% | — |
| 2005 | 75.2 | 39.7% | — |
| 2006 | 79.9 | 42.2% | — |
| 2007 | 82.2 | 43.5% | — |
| 2008 | 94.1 | 49.6% | — |
| 2009 | 93.4 | 49.4% | — |
| 2010 | 81.6 | 43.1% | — |
| 2011 | 88.5 | 46.8% | — |
| 2012 | 85.6 | 45.1% | — |
| 2013 | 80 | 42.3% | — |
| 2014 | 69 | 36.5% | — |
| 2015 | 58 | 30.6% | — |
| 2016 | 71.9 | 37.9% | — |
| 2017 | 61.8 | 32.6% | — |
| 2018 | 62.4 | 72.0% | — |
| 2019 | 68.6 | 79.1% | — |
| 2020 | 74.9 | 86.2% | — |
| 2021 | 71.1 | 82.0% | — |
| 2022 | 51.9 | 59.9% | — |
| 2023 | 62.3 | 71.9% | — |
| 2024 | 82.3 | 94.7% | — |
| 2025 | 83.8 | 96.6% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| 1 | Geothermal | BT | 5 | 3.3 | Dec 1990 | Operating | — | coming soon |
| 2 | Geothermal | BT | 5 | 3.3 | Dec 1990 | Operating | — | coming soon |
| 3 | Geothermal | BT | 5 | 3.3 | Dec 1990 | Operating | — | coming soon |
| T101 | Geothermal | BT | 5 | 3.8 | Dec 1990 | Retired Apr 2013 | — | coming soon |
| T102 | Geothermal | BT | 5 | 4.6 | Dec 1990 | Retired Apr 2013 | — | coming soon |
| T103 | Geothermal | BT | 5 | 4.2 | Dec 1990 | Retired Apr 2013 | — | coming soon |
Owner / operator
Operator: Ormat Nevada Inc. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Mammoth Pacific LP | 100.0% | 15 MW |
Nearby plants
Within 80 km.
| Ples I | 15 MW | 0.1 km |
| Mammoth Pacific I | 10 MW | 0.5 km |
| CD4 | 44 MW | 0.6 km |
| Rush Creek | 13 MW | 23.1 km |
| Upper Gorge | 38 MW | 30.3 km |
| Middle Gorge | 38 MW | 33.6 km |