Hennepin Island

Hydro power plant in Minnesota, United States of America. Approximate location 44.9824, -93.2542.

HydroMinnesotaUnited States of America

Hennepin Island is a 14 MW hydro power plant in Minnesota, United States of America. It is operated by Northern States Power Co - Minnesota. Based on reported annual generation of 64 GWh, it can supply roughly 18k homes. It ranks #5286 of 10,938 United States of America power plants by installed capacity. Commissioned in 1954, it is around 72 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).

14Source-backed capacity
64GWh reported / yr
18,342homes powered
1954commissioned (~72 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0001911.

Data status

Known data

FacilityHennepin Island WRI
CountryUnited States of America · Minnesota WRI
Coordinates44.9824, -93.2542 WRI
FuelHydro WRI
MW installed capacity14 MW WRI source record; scope not independently normalised
OwnerNorthern States Power Co - Minnesota WRI
Commissioned1954 WRI
GWh reported / yr64 GWh/yr WRI

Calculated from dataset

Capacity rank in country#5286 of 10938 calculated
Fuel-specific rank in country#562 of 1449 calculated
Capacity vs country/fuel peers1.71× · 8 MW median · 1449 peers calculated
Homes-powered equivalent18,342 calculated from reported generation
Climate7.6°C · HDD 4,122 derived from coordinates
Environmental severityC2 · 34/100 derived from coordinates

Not available

TechnologyNot available not in dataset
GWh reported / yrNot available not in dataset
CO₂ emissionsnot applicable not applicable

Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.

Data provenance

The capacity and/or fuel fields on this page include a source-backed provenance label from GEM, an official registry, Wikidata, OSM, or a cross-source match.

capacity: Wikidata P2109 nameplate capacity; fuel: WRI source-record fuel

In context: how this plant compares

At 14 MW, Hennepin Island 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.

Reported generation trend

2013: 36 GWh20132014: 63 GWh20142015: 81 GWh20152016: 94 GWh20162017: 74 GWh20172018: 61 GWh20182019: 64 GWh201994 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 hot-summer humid continental climate (Köppen Dfa) — Northern Hemisphere, latitude 45.0°N — which shapes how much energy it can produce and how its output varies through the year.

7.6°Cannual mean temp
4,122heating degree-days (base 18°C)
343cooling degree-days (base 18°C)
255 melevation

Monthly mean temperature

J: -11 °CJF: -7 °CFM: 0 °CMA: 8 °CAM: 16 °CMJ: 21 °CJJ: 23 °CJA: 22 °CAS: 16 °CSO: 10 °CON: 0 °CND: -7 °CD23 °C

Heating degree-days here run 68% 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.

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

For a plant’s outdoor hardware — heat-recovery steam generators (HRSG), expansion joints, valves, flanges and their insulation — the local climate sets how fast unprotected steel and coatings degrade. This site sits in a mild atmospheric environment (estimated ISO 9223 class C2 — Low), with thermal cycling the leading environmental stress.

C2ISO 9223 corrosivity (indicative)
34/100environmental-severity index
33.7°Cseasonal temperature swing
334 kmdistance to coast

Higher environmental severity is exactly where protective removable insulation pays back most: a sheltered micro-climate slows corrosion, UV and thermal-cycling damage and extends outdoor hardware service life. This is an indicative site-climate context — not a condition assessment of any specific plant or operator.

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 #562 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

Location

Coordinates 44.9824, -93.2542 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Hennepin Island?

Hennepin Island is a 14 MW source-record hydro power plant in Minnesota, United States of America, commissioned in 1954.

How much electricity does Hennepin Island generate?

Hennepin Island generates about 64 GWh of electricity per year.

How many homes can Hennepin Island power?

Its output is enough to supply roughly 18,342 homes.

Who operates Hennepin Island?

Hennepin Island is operated by Northern States Power Co - Minnesota.

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