Marathon Bay Area Cogen — United States of America
Gas power plant in California, United States of America. Approximate location 38.021, -122.0675.
GasCaliforniaUnited States of AmericaCO₂ modelled
Marathon Bay Area Cogen is a 113.5 MW gas power station in California, United States of America. It is operated by Tesoro Refining & Marketing Company LLC. Based on its capacity (estimated), it can supply roughly 128k homes (estimated). It ranks #2595 of 10,884 United States of America power plants by installed capacity. Its modelled annual emissions are 117,792 t CO₂/yr (Climate TRACE), equivalent to about 27k cars driven for a year. In context, gas supplies about 40.0% 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 CT-967.
Data status
Known data
Modelled source data
Calculated from dataset
Not available
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
Data provenance
Source of the capacity and fuel values:
capacity: Wikidata P2109; fuel: Climate TRACE
In context: how this plant compares
At 113.5 MW, Marathon Bay Area Cogen is around the median gas plant in United States of America (121.2 MW). Gas plants burn natural gas either in open-cycle turbines for fast peaking, or in combined-cycle units that recover exhaust heat in an HRSG to reach roughly 55–62% efficiency — the cleanest-burning fossil option.
Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.
~117,792 t CO₂/yr (modelled) — in everyday terms
This facility's annual emissions are roughly equivalent to:
Equivalencies via US EPA Greenhouse Gas Equivalencies; modelled emissions from Climate TRACE.
Key facts
- Share of United States of America gas capacity
- less than 0.1% of 789,950 MW across 2,165 plants in this dataset
Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).
Capacity vs largest gas plants in United States of America
Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).
Owner
Operated by Tesoro Refining & Marketing Company LLC.
Local climate & thermal context
This gas plant burns natural gas in a turbine — often in a combined-cycle setup — to generate electricity. It sits in a warm-summer Mediterranean climate (Köppen Csb) — Northern Hemisphere, latitude 38.0°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 43% below 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: 32/100 — this site sits in the bottom third of the power plants we cover by heating degree-days.
A gas turbine here also runs ~0% below its ISO (15°C) rating at this annual mean (typical CCGT curve, estimate).
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 moderately corrosive environment (estimated ISO 9223 class C3 — Medium), 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 #1107 largest gas power plant of 2165 in United States of America by capacity.
United States of America has 2165 gas power plants in this dataset, together about 789,950 MW of capacity.
Nearby power plants
- Foster Wheeler Martinez · Gas · 113.5 MW · California
- CCCSD Wastewater Treatment Plnt · Gas · 3.5 MW · California
- Martinez Refining · Gas · 100 MW · California
- Martinez Sulfuric Acid Regeneration Plt · Cogeneration · 4 MW · California
- Valero Refinery Cogeneration Unit 1 · Gas · 50 MW · California
- Ameresco Keller Canyon · Waste · 3.8 MW · California
Location
Coordinates 38.021, -122.0675 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Frequently asked questions
What type of power plant is Marathon Bay Area Cogen?
Marathon Bay Area Cogen is a 113.5 MW gas power plant in California, United States of America.
Who operates Marathon Bay Area Cogen?
Marathon Bay Area Cogen is operated by Tesoro Refining & Marketing Company LLC.
How much CO₂ does Marathon Bay Area Cogen emit?
Marathon Bay Area Cogen has modelled emissions of about 117,792 tonnes of CO₂ per year (Climate TRACE).