Top of Iowa Windfarm III — United States of America

Top of Iowa Windfarm III is a 29.7 MW wind power plant in Iowa, United States of America. It is operated by Madison Gas & Electric Co. Based on reported annual generation of 67 GWh, it can supply roughly 19k homes. It ranks #4281 of 10,884 United States of America power plants by installed capacity. Commissioned in 2008, it is around 18 years old — relatively modern. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, wind supplies about 10.3% of United States of America's electricity; the national grid averages 384 gCO₂/kWh (43.0% low-carbon) (2025).

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0056386.

Data provenance

Source of the capacity and fuel values:

capacity: Wikidata P2109; fuel: WRI GPPD

In context: how this plant compares

At 29.7 MW, Top of Iowa Windfarm III is below the median wind plant in United States of America (67.7 MW). Wind turbines convert moving air into electricity; output is variable and site-dependent, and modern turbines deliver some of the lowest-cost new generation on many grids.

Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.

Key facts

Load factor

26%, from 67 GWh of reported generation; the median for 1120 wind plants in United States of America that report generation is 30%

Generation trend

81 GWh in 2013 and 67 GWh in 2019 (−18%)

Highest and lowest year

2014: 92 GWh; 2019: 67 GWh

Share of United States of America wind capacity

less than 0.1% of 104,873 MW across 1,139 plants in this dataset

Age among peers

257 of 1,139 dated wind plants in United States of America are older

Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).

Reported generation trend

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

Owner

Operated by Madison Gas & Electric Co. All plants by this company →

Local climate & thermal context

This wind plant converts the kinetic energy of wind into electricity through turbine rotors. It sits in a hot-summer humid continental climate (Köppen Dfa) — Northern Hemisphere, latitude 43.4°N — which shapes how much energy it can produce and how its output varies through the year.

Monthly mean temperature

Heating degree-days here run 67% 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: 85/100 — 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

This site sits in a mild atmospheric environment (estimated ISO 9223 class C2 — Low), with thermal cycling the leading environmental stress.

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 #722 largest wind power plant of 1139 in United States of America by capacity.

United States of America has 1139 wind power plants in this dataset, together about 104,873 MW of capacity.

Nearby power plants

• Northern Iowa Windpower II · Wind · 80 MW · Iowa
• Roeder Family Wind Farm LLC · Wind · 1.6 MW · Iowa
• Northern Iowa Windfarm · Wind · 80 MW · Iowa
• Windwalkers LLC · Wind · 1.6 MW · Iowa
• POET Biorefining-Hanlontown LLC · Gas · 4 MW · Iowa
• Lime Creek · Oil · 90.2 MW · Iowa

Location

Coordinates 43.3597, -93.3208 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions