Lower Granite
Whitman County, Washington · EIA plant ID 6175 · Operator: USACE Northwestern Division
Nameplate810MWSummer 802 MW
Generators6in service
Net generation1,464GWh12 mo to Aug 2026
Capacity factor21%hydro units, summer MW
Heat rate—thermal plants only
First online1975
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), hydro 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 | 1,891 | 23.2% | — |
| 2002 | 2,026.5 | 24.8% | — |
| 2003 | 2,161.5 | 26.5% | — |
| 2004 | 2,222.3 | 31.2% | — |
| 2005 | 1,791.6 | 25.3% | — |
| 2006 | 2,551.6 | 36.0% | — |
| 2007 | 1,681.7 | 23.7% | — |
| 2008 | 2,073 | 29.1% | — |
| 2009 | 2,371.3 | 33.4% | — |
| 2010 | 1,836.8 | 25.9% | — |
| 2011 | 3,156.3 | 44.5% | — |
| 2012 | 2,417.4 | 34.0% | — |
| 2013 | 1,680.2 | 23.7% | — |
| 2014 | 2,284.8 | 32.2% | — |
| 2015 | 1,698.5 | 23.9% | — |
| 2016 | 2,104.1 | 29.6% | — |
| 2017 | 2,666.5 | 38.0% | — |
| 2018 | 2,466.7 | 35.1% | — |
| 2019 | 2,192.8 | 31.2% | — |
| 2020 | 1,710.2 | 24.3% | — |
| 2021 | 1,347.6 | 19.2% | — |
| 2022 | 1,721.1 | 24.5% | — |
| 2023 | 1,541.8 | 21.9% | — |
| 2024 | 1,273.5 | 18.1% | — |
| 2025 | 1,461 | 20.8% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| 1 | Conventional Hydroelectric | HY | 135 | 135 | Apr 1975 | Operating (Out of service, expected back within the year) | — | coming soon |
| 2 | Conventional Hydroelectric | HY | 135 | 127 | May 1975 | Operating | — | coming soon |
| 3 | Conventional Hydroelectric | HY | 135 | 135 | Jun 1975 | Operating | — | coming soon |
| 4 | Conventional Hydroelectric | HY | 135 | 135 | Feb 1978 | Operating | — | coming soon |
| 5 | Conventional Hydroelectric | HY | 135 | 135 | Apr 1978 | Operating | — | coming soon |
| 6 | Conventional Hydroelectric | HY | 135 | 135 | Apr 1978 | Operating | — | coming soon |
Owner / operator
Operator: USACE Northwestern Division. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| USACE Northwestern Division | 100.0% | 810 MW |
Nearby plants
Within 80 km.
| Biotech LS 0836 | 1 MW | 22.2 km |
| Grimes Way | 4 MW | 22.6 km |
| Lower Snake River Wind Energy Project | 343 MW | 33.5 km |
| Lower Snake Solar Generation BESS | — | 35 km |
| Hopkins Ridge Wind | 157 MW | 40.7 km |
| Marengo Wind Plant | 234 MW | 41.4 km |