Marathon Generating PlantRetired
Monroe County, Florida · EIA plant ID 696 · Operator: Florida Keys El Coop Assn, Inc
×11 MW oil retired since 2020 (latest May 2025)
Nameplate—MWSummer — MW
Generators0in service
Net generation—GWh12 mo
Capacity factor—no 923 generation in the last 12 months
Heat rate—Btu/kWhfossil units, electric fuel, HHV
First online—
Monthly net generation
EIA-923, all units at the plant. Net of station use; storage can go negative.
FinalPreliminary
Capacity factor by year
Net MWh ÷ (summer MW × hours), primary-fuel units. Each year uses that year's EIA-860 ratings; the hollow dot is the latest 12 months.
Heat rate by year
Electric fuel MMBtu × 1000 ÷ net MWh (Btu/kWh, HHV), fossil units only; CT + CA counted as one combined-cycle block.
Annual data table
| Year | Net GWh | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|
| 2001 | 0.4 | 0.2% | 29,862 |
| 2002 | 1.5 | 0.7% | 13,760 |
| 2003 | 2.6 | 1.3% | 12,713 |
| 2004 | 1.4 | 0.6% | 13,025 |
| 2005 | 1.7 | 0.8% | 13,615 |
| 2006 | 0.7 | 0.3% | 13,379 |
| 2007 | 0.6 | 0.3% | 15,775 |
| 2008 | 0 | 0.0% | — |
| 2009 | 0 | 0.0% | — |
| 2010 | 0 | 0.0% | — |
| 2011 | -0.4 | -0.2% | — |
| 2012 | -0.4 | -0.2% | — |
| 2013 | -0.4 | -0.2% | — |
| 2014 | -0.3 | -0.1% | — |
| 2015 | -0.2 | -0.1% | — |
| 2016 | -0.1 | -0.1% | — |
| 2017 | -0.3 | -0.2% | — |
| 2018 | -1.2 | -0.7% | — |
| 2019 | -0.3 | -0.3% | — |
| 2020 | -0.2 | -0.2% | — |
| 2021 | -0.2 | -0.3% | — |
| 2022 | -0.2 | -0.2% | — |
| 2023 | -0 | 0.0% | — |
| 2024 | 0 | 0.1% | 9,792 |
| 2025 | 0 | 0.0% | 28,364 |
Generators
EIA-860 (annual) with EIA-860M updates through Sep 2026. EIA-923 reports generation by plant, prime mover and fuel, not by unit, so unit-level output isn't shown.
| Gen ID | Technology | Prime mover | Nameplate MW | Summer MW | Online | Status | Planned retirement | OEM / model |
|---|---|---|---|---|---|---|---|---|
| 10 | Petroleum Liquids | IC | 3.5 | 3.5 | Jan 1998 | Retired May 2025 | — | coming soon |
| 11 | Petroleum Liquids | IC | 3.5 | 3.5 | Jan 2001 | Retired May 2025 | — | coming soon |
| 3 | Petroleum Liquids | IC | 3 | 3 | Jan 1958 | Retired Nov 2018 | — | coming soon |
| 4 | Petroleum Liquids | IC | 3 | 3 | Jan 1959 | Retired Nov 2018 | — | coming soon |
| 5 | Petroleum Liquids | IC | 3 | 3 | Jan 1959 | Retired Jan 2007 | — | coming soon |
| 6 | Petroleum Liquids | IC | 2.5 | 2.5 | May 1973 | Retired Nov 2018 | — | coming soon |
| 7 | Petroleum Liquids | IC | 2.5 | 2.5 | Jan 1973 | Retired Nov 2018 | — | coming soon |
| 8 | Petroleum Liquids | IC | 2 | 2 | May 1989 | Retired May 2025 | — | coming soon |
| 9 | Petroleum Liquids | IC | 2 | 2 | May 1989 | Retired May 2025 | — | coming soon |
Owner / operator
Operator: Florida Keys El Coop Assn, Inc. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
Nearby plants
Within 80 km.
| Stock Island | 126 MW | 66.9 km |