Mammoth Pacific I
Mono County, California · EIA plant ID 10480 · Operator: Ormat Nevada Inc
Nameplate10MWSummer 7 MW
Generators2in service
Net generation44GWh12 mo to Dec 2025
Capacity factor75%geothermal units, summer MW
Heat rate—thermal plants only
First online1984
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 | 51 | 100.4% | — |
| 2002 | 44.7 | 87.9% | — |
| 2003 | 43.2 | 85.0% | — |
| 2005 | 38.5 | 75.9% | — |
| 2006 | 40.3 | 79.4% | — |
| 2007 | 39 | 76.8% | — |
| 2008 | 42.9 | 84.2% | — |
| 2009 | 44.1 | 86.8% | — |
| 2010 | 49.1 | 96.7% | — |
| 2011 | 34.1 | 67.1% | — |
| 2012 | 17.9 | 35.1% | — |
| 2013 | 2 | 4.0% | — |
| 2014 | 56.3 | 100.4% | — |
| 2015 | 51.4 | 91.8% | — |
| 2016 | 58.9 | 104.9% | — |
| 2017 | 58.7 | 104.7% | — |
| 2018 | 56.8 | 98.3% | — |
| 2019 | 57.4 | 99.2% | — |
| 2020 | 58.5 | 100.8% | — |
| 2021 | 59.2 | 102.4% | — |
| 2022 | 45.4 | 78.5% | — |
| 2023 | 57.7 | 99.8% | — |
| 2024 | 59.6 | 102.8% | — |
| 2025 | 43.6 | 75.4% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| GEN1 | Geothermal | BT | 5 | 3.3 | Dec 1984 | Operating | — | coming soon |
| GEN2 | Geothermal | BT | 5 | 3.3 | Dec 1984 | Operating | — | 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% | 10 MW |
Nearby plants
Within 80 km.
| CD4 | 44 MW | 0.2 km |
| Ples I | 15 MW | 0.4 km |
| Mammoth Pacific II | 15 MW | 0.5 km |
| Rush Creek | 13 MW | 22.8 km |
| Upper Gorge | 38 MW | 30.6 km |
| Middle Gorge | 38 MW | 33.9 km |