Libby

Hydro power plant in Montana, United States of America. Approximate location 48.4098, -115.3143.

HydroMontanaUnited States of America

Libby is a 525 MW hydro power station in Montana, United States of America. It is operated by USACE Northwestern Division. Based on reported annual generation of 1,511 GWh, it can supply roughly 431,828 homes. It ranks #710 of 9,833 United States of America power plants by installed capacity. Commissioned in 1977, it is around 49 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).

525MW installed capacity
1,511GWh reported / yr
431,828homes powered
1977commissioned (~49 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0006172.

Reported generation trend

2013: 2,306 GWh20132014: 2,514 GWh20142015: 1,758 GWh20152016: 2,186 GWh20162017: 2,281 GWh20172018: 2,056 GWh20182019: 1,511 GWh20193k GWh

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 humid continental climate (Köppen Dfb) — Northern Hemisphere, latitude 48.4°N — which shapes how much energy it can produce and how its output varies through the year.

5.8°Cannual mean temp
4,442heating degree-days (base 18°C)
0cooling degree-days (base 18°C)
1,146 melevation

Monthly mean temperature

J: -5 °CJF: -2 °CFM: 1 °CMA: 5 °CAM: 10 °CMJ: 14 °CJJ: 17 °CJA: 17 °CAS: 12 °CSO: 6 °CON: 0 °CND: -5 °CD17 °C

Heating degree-days here run 81% 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: 90/100 — this site sits in the top third of the power plants we cover by heating degree-days.

In colder climates, uninsulated hot equipment (boilers, turbines, valves, steam lines) loses proportionally more heat to ambient air — exactly the loss Inzonex modular insulation is designed to cut.

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.

How it compares & nearby plants

The #46 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 101,657 MW of capacity.

Nearby power plants

Location

Coordinates 48.4098, -115.3143 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

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