Milner Hydro

Hydro power plant in Idaho, United States of America. Approximate location 42.5268, -114.0369.

HydroIdahoUnited States of America

Milner Hydro is a 60 MW hydro power plant in Idaho, United States of America. It is operated by Idaho Power Co. Based on reported annual generation of 157 GWh, it can supply roughly 44,914 homes. It ranks #2558 of 9,833 United States of America power plants by installed capacity. Commissioned in 1992, it is around 34 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).

60MW installed capacity
157GWh reported / yr
44,914homes powered
1992commissioned (~34 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0007190.

Reported generation trend

2013: 53 GWh20132014: 54 GWh20142015: 71 GWh20152016: 28 GWh20162017: 238 GWh20172018: 294 GWh20182019: 157 GWh2019294 GWh

Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by Idaho Power Co. 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 cold semi-arid steppe climate (Köppen BSk) — Northern Hemisphere, latitude 42.5°N — which shapes how much energy it can produce and how its output varies through the year.

8.7°Cannual mean temp
3,541heating degree-days (base 18°C)
149cooling degree-days (base 18°C)
1,325 melevation

Monthly mean temperature

J: -3 °CJF: 0 °CFM: 4 °CMA: 8 °CAM: 12 °CMJ: 17 °CJJ: 21 °CJA: 20 °CAS: 15 °CSO: 10 °CON: 2 °CND: -2 °CD21 °C

Heating degree-days here run 44% 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: 77/100 — 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 #269 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 42.5268, -114.0369 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

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