Lower Granite — United States of America
Hydro power plant in Washington, United States of America. Approximate location 46.6595, -117.4294.
HydroWashingtonUnited States of America
Lower Granite is a 810 MW hydro power station in Washington, United States of America. It is operated by USACE Northwestern Division. Based on reported annual generation of 2,193 GWh, it can supply roughly 627k homes. It ranks #765 of 10,884 United States of America power plants by installed capacity. Commissioned in 1976, it is around 50 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 5.3% of United States of America's electricity; the national grid averages 384 gCO₂/kWh (43.0% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0006175.
Data status
Known data
Calculated from dataset
Not available
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
Data provenance
Source of the capacity and fuel values:
capacity: GEM · 2026 · L100000603853; fuel: WRI GPPD
In context: how this plant compares
At 810 MW, Lower Granite is well above the median hydro plant in United States of America (8 MW). Hydropower converts the energy of falling or flowing water into electricity; output depends on rainfall and reservoir level, and large dams also provide grid balancing and storage.
Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.
Key facts
- Load factor
- 31%, from 2,193 GWh of reported generation; the median for 1342 hydro plants in United States of America that report generation is 42%
- Generation trend
- 1,680 GWh in 2013 and 2,193 GWh in 2019 (+31%)
- Highest and lowest year
- 2017: 2,666 GWh; 2013: 1,680 GWh
- Share of United States of America hydro capacity
- 0.8% of 102,513 MW across 1,449 plants in this dataset
- Age among peers
- 904 of 1,444 dated hydro plants in United States of America are older
Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).
Reported generation trend
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
Owner
Operated by USACE Northwestern Division. All plants by this company →
Local climate & thermal context
This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a warm-summer Mediterranean climate (Köppen Csb) — Northern Hemisphere, latitude 46.7°N — which shapes how much energy it can produce and how its output varies through the year.
Monthly mean temperature
Heating degree-days here run 29% above the median power plant in this dataset — a proxy for how much extra energy heated equipment must replace through its surfaces in winter.
Climate heat-demand index: 67/100 — this site sits in the top third of the power plants we cover by heating degree-days.
Climate normals: WorldClim 2.1 (1970–2000 monthly normals, 10 arc-min, CC BY 4.0); zone: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid). Degree-days & heat-demand index computed by PowerAtlas — a modelled heat-demand proxy, not a measured site figure.
Site climate & environmental severity
This site sits in a mild atmospheric environment (estimated ISO 9223 class C2 — Low), with humidity / wetness the leading environmental stress.
Indicative estimate via the ISO 9223:2012 informative method (atmospheric corrosivity from temperature, time-of-wetness and airborne salinity), using WorldClim climate normals, the Köppen-Geiger class and coast distance. Indicative, not a measured corrosion rate.
How it compares & nearby plants
The #27 largest hydro power plant of 1449 in United States of America by capacity.
United States of America has 1449 hydro power plants in this dataset, together about 102,513 MW of capacity.
Nearby power plants
- Biotech LS 0836 · Oil · 1 MW · Washington
- Grimes Way · Gas · 4 MW · Washington
- Lower Snake River Wind Energy Project · Wind · 342.7 MW · Washington
- Marengo Wind Plant · Wind · 234 MW · Washington
- Hopkins Ridge Wind · Wind · 149.4 MW · Washington
- Clearwater Paper IPP Lewiston · Biomass · 113.8 MW · Idaho
Location
Coordinates 46.6595, -117.4294 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Frequently asked questions
What type of power plant is Lower Granite?
Lower Granite is a 810 MW hydro power plant in Washington, United States of America, commissioned in 1976.
How much electricity does Lower Granite generate?
Lower Granite generates about 2,193 GWh of electricity per year.
Who operates Lower Granite?
Lower Granite is operated by USACE Northwestern Division.