Coso Power Developers
Inyo County, California · EIA plant ID 10874 · Operator: Coso Operating Co LLC
Nameplate90MWSummer 80 MW
Generators3in service
Net generation314GWh12 mo to Aug 2026
Capacity factor45%geothermal units, summer MW
Heat rate—thermal plants only
First online1989
The 12-month figures include preliminary EIA-923 months, which EIA revises. Final data runs through Dec 2025.
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 | 783.1 | 112.0% | — |
| 2002 | 774.4 | 110.8% | — |
| 2003 | 734.8 | 99.2% | — |
| 2004 | 746.5 | 100.4% | — |
| 2005 | 695.3 | 93.8% | — |
| 2006 | 642.8 | 86.7% | — |
| 2007 | 586.6 | 83.4% | — |
| 2008 | 574.6 | 81.5% | — |
| 2009 | 576.5 | 82.0% | — |
| 2010 | 586.5 | 83.4% | — |
| 2011 | 532.8 | 75.7% | — |
| 2012 | 527 | 74.7% | — |
| 2013 | 488.7 | 69.5% | — |
| 2014 | 449.2 | 63.8% | — |
| 2015 | 439.3 | 62.5% | — |
| 2016 | 473.8 | 67.2% | — |
| 2017 | 404 | 57.4% | — |
| 2018 | 410.1 | 58.3% | — |
| 2019 | 408.9 | 58.1% | — |
| 2020 | 396.8 | 56.3% | — |
| 2021 | 364.5 | 51.8% | — |
| 2022 | 386 | 54.9% | — |
| 2023 | 363.9 | 51.7% | — |
| 2024 | 310 | 44.0% | — |
| 2025 | 315.1 | 44.8% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| GEN4 | Geothermal | ST | 30 | 30 | Nov 1989 | Operating | — | coming soon |
| GEN5 | Geothermal | ST | 30 | 23.4 | Dec 1989 | Operating | — | coming soon |
| GEN6 | Geothermal | ST | 30 | 26.9 | Dec 1989 | Operating | — | coming soon |
Owner / operator
Operator: Coso Operating Co LLC. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Coso Operating Co LLC | 100.0% | 90 MW |
Nearby plants
Within 80 km.
| Coso Energy Developers | 90 MW | 1.9 km |
| Coso Finance Partners | 92 MW | 2.1 km |
| Coso Battery Storage | 60 MW | 2.2 km |
| Mordor ES1 | 25 MW | 2.3 km |
| Mordor ES2 | 20 MW | 2.4 km |
| Haiwee | 6 MW | 17.9 km |