Orrtanna — United States of America

Orrtanna is a 27 MW oil power plant in Pennsylvania, United States of America. It is operated by Orrtanna Power LLC. Based on its capacity (estimated), it can supply roughly 20k homes (estimated). It ranks #4358 of 10,884 United States of America power plants by installed capacity. Commissioned in 1971, it is around 55 years old — an older, legacy facility. In context, oil supplies about 0.7% 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 USA0003112.

Data provenance

Source of the capacity and fuel values:

capacity: Wikidata P2109; fuel: WRI GPPD

In context: how this plant compares

At 27 MW, Orrtanna is well above the median oil plant in United States of America (7.2 MW). Oil-fired plants burn heavy fuel oil or diesel, usually as peaking or backup capacity on islands and grids without gas pipelines; high fuel cost keeps their utilisation low.

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

Key facts

Generation trend

0 GWh in 2013 and 0 GWh in 2018 (−33%)

Highest and lowest year

2014: 2 GWh; 2018: 0 GWh

Share of United States of America oil capacity

less than 0.1% of 40,022 MW across 902 plants in this dataset

Age among peers

137 of 877 dated oil 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 Orrtanna Power LLC.

Local climate & thermal context

This oil plant burns oil or diesel to drive turbines or reciprocating engines. It sits in a humid subtropical climate (Köppen Cfa) — Northern Hemisphere, latitude 39.8°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 14% 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: 57/100 — this site sits in the mid 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 humidity / wetness 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 #164 largest oil power plant of 902 in United States of America by capacity.

United States of America has 902 oil power plants in this dataset, together about 40,022 MW of capacity.

Nearby power plants

• Hunterstown Power Plant · Gas · 898 MW · Pennsylvania
• Hunterstown · Oil · 60 MW · Pennsylvania
• Emmitsburg Solar Arrays · Solar · 1.7 MW · Maryland
• Mount Saint Mary's · Solar · 13.7 MW · Maryland
• Blue Ridge Landfill · Waste · 6.4 MW · Pennsylvania
• Knouse Solar Project 1 · Solar · 3 MW · Pennsylvania

Location

Coordinates 39.8442, -77.3508 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions