Geothermal 1
Sonoma County, California · EIA plant ID 7368 · Operator: Northern California Power Agny
Nameplate110MWSummer 60 MW
Generators2in service
Net generation309GWh12 mo to Aug 2026
Capacity factor59%geothermal units, summer MW
Heat rate—thermal plants only
First online1983
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) |
|---|---|---|---|
| 2002 | 599.8 | 58.0% | — |
| 2003 | 534.1 | 95.0% | — |
| 2004 | 531.8 | 94.3% | — |
| 2005 | 525.5 | 54.5% | — |
| 2006 | 522.6 | 55.1% | — |
| 2007 | 506.4 | 88.0% | — |
| 2008 | 490.5 | 85.0% | — |
| 2009 | 471.1 | 81.9% | — |
| 2010 | 453.5 | 78.8% | — |
| 2011 | 435.7 | 75.7% | — |
| 2012 | 458.2 | 104.3% | — |
| 2013 | 388.7 | 85.3% | — |
| 2014 | 469.5 | 103.1% | — |
| 2015 | 460.8 | 101.2% | — |
| 2016 | 475.2 | 100.2% | — |
| 2017 | 415.9 | 87.9% | — |
| 2018 | 433.9 | 105.4% | — |
| 2019 | 324.6 | 78.8% | — |
| 2020 | 454.6 | 101.5% | — |
| 2021 | 481.4 | 107.8% | — |
| 2022 | 488 | 109.2% | — |
| 2023 | 334.8 | 63.7% | — |
| 2024 | 278.2 | 52.8% | — |
| 2025 | 338.4 | 64.4% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| 1 | Geothermal | ST | 55 | 30 | Jan 1983 | Operating | — | coming soon |
| 2 | Geothermal | ST | 55 | 30 | Jan 1983 | Operating | — | coming soon |
Owner / operator
Operator: Northern California Power Agny. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Northern California Power Agny | 100.0% | 110 MW |
Nearby plants
Within 80 km.
| Geothermal 2 | 110 MW | 0.7 km |
| Bear Canyon | 13 MW | 2.6 km |
| Geysers Unit 5-20 | 1,236 MW | 3.6 km |
| West Ford Flat | 25 MW | 4 km |
| Calistoga Power Plant | 176 MW | 4.5 km |
| Sonoma California Geothermal | 78 MW | 5.3 km |