Wind power plant in Maryland, United States of America. Approximate location 39.6294, -79.018.
WindMarylandUnited States of America
Fourmile Ridge is a 40 MW wind power plant in Maryland, United States of America. It is operated by Fourmile Wind Energy LLC. Based on reported annual generation of 126 GWh, it can supply roughly 36k homes. It ranks #3997 of 10,938 United States of America power plants by installed capacity. Commissioned in 2015, it is around 11 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 USA0058904.
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
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: GEM tracker 2026 (location L100000906609); fuel: WRI source-record fuel
At 40 MW, Fourmile Ridge is below the median wind plant in United States of America (68 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.
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
Operated by Fourmile Wind Energy LLC.
This wind plant converts the kinetic energy of wind into electricity through turbine rotors. It sits in a temperate oceanic climate (Köppen Cfb) — Northern Hemisphere, latitude 39.6°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 30% 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: 68/100 — 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.
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 humidity / wetness the leading environmental stress.
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.
The #678 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.
Coordinates 39.6294, -79.018 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Fourmile Ridge is a 40 MW source-record wind power plant in Maryland, United States of America, commissioned in 2015.
Fourmile Ridge generates about 126 GWh of electricity per year.
Its output is enough to supply roughly 35,857 homes.
Fourmile Ridge is operated by Fourmile Wind Energy LLC.
