Thornapple

Hydro power plant in Wisconsin, United States of America. Approximate location 45.4111, -91.2183.

HydroWisconsinUnited States of America

Thornapple is a 1 MW hydro power plant in Wisconsin, United States of America. It is operated by Northern States Power Co - Minnesota. Based on reported annual generation of 10 GWh, it can supply roughly 2,800 homes. It ranks #8973 of 9,833 United States of America power plants by installed capacity. Commissioned in 1928, it is around 98 years old — an older, legacy facility. 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).

1MW installed capacity
10GWh reported / yr
2,800homes powered
1928commissioned (~98 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0003988.

Reported generation trend

2013: 8 GWh20132014: 10 GWh20142015: 10 GWh20152016: 12 GWh20162017: 11 GWh20172018: 10 GWh20182019: 10 GWh201912 GWh

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

Owner

Operated by Northern States Power Co - Minnesota. 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 45.4°N — which shapes how much energy it can produce and how its output varies through the year.

5.7°Cannual mean temp
4,590heating degree-days (base 18°C)
112cooling degree-days (base 18°C)
334 melevation

Monthly mean temperature

J: -12 °CJF: -8 °CFM: -2 °CMA: 6 °CAM: 13 °CMJ: 18 °CJJ: 20 °CJA: 19 °CAS: 14 °CSO: 8 °CON: -1 °CND: -8 °CD20 °C

Heating degree-days here run 87% 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: 91/100 — 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 #1334 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 45.4111, -91.2183 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

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