Gem State

Hydro power plant in Idaho, United States of America. Approximate location 43.4202, -112.1019.

HydroIdahoUnited States of America

Gem State is a 23 MW hydro power plant in Idaho, United States of America. It is operated by City of Idaho Falls - (ID). Based on reported annual generation of 131 GWh, it can supply roughly 37,342 homes. It ranks #3519 of 9,833 United States of America power plants by installed capacity. Commissioned in 1988, it is around 38 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).

23MW installed capacity
131GWh reported / yr
37,342homes powered
1988commissioned (~38 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0000790.

Reported generation trend

2013: 114 GWh20132014: 124 GWh20142015: 118 GWh20152016: 117 GWh20162017: 148 GWh20172018: 145 GWh20182019: 131 GWh2019148 GWh

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

Owner

Operated by City of Idaho Falls - (ID). 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 43.4°N — which shapes how much energy it can produce and how its output varies through the year.

6.7°Cannual mean temp
4,174heating degree-days (base 18°C)
78cooling degree-days (base 18°C)
1,432 melevation

Monthly mean temperature

J: -6 °CJF: -3 °CFM: 2 °CMA: 6 °CAM: 11 °CMJ: 16 °CJJ: 20 °CJA: 19 °CAS: 14 °CSO: 8 °CON: 0 °CND: -5 °CD20 °C

Heating degree-days here run 70% 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: 86/100 — 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 #446 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 43.4202, -112.1019 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

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