Diamond Island Plant
Jefferson County, New York · EIA plant ID 10540 · Operator: Energen Renewables, LLC
Nameplate1MWSummer 1 MW
Generators3in service
Net generation2GWh12 mo to Dec 2025
Capacity factor17%hydro units, summer MW
Heat rate—thermal plants only
First online1914
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), hydro 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.
Heat rate applies to fuel-burning (thermal) units only.
Annual data table
| Year | Net GWh | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|
| 2001 | 6.4 | 64.3% | — |
| 2002 | 6 | 60.4% | — |
| 2003 | 5.5 | 54.9% | — |
| 2005 | 6.8 | 67.7% | — |
| 2006 | 7.8 | 78.5% | — |
| 2007 | 5.4 | 51.8% | — |
| 2008 | 7.6 | 72.3% | — |
| 2009 | 7.8 | 74.2% | — |
| 2010 | 6.3 | 59.9% | — |
| 2011 | 6.3 | 59.5% | — |
| 2012 | 5.6 | 53.1% | — |
| 2013 | 5.8 | 55.6% | — |
| 2014 | 6.3 | 60.1% | — |
| 2015 | 4.8 | 45.7% | — |
| 2016 | 5.3 | 49.9% | — |
| 2017 | 7.1 | 67.2% | — |
| 2018 | 5.1 | 48.6% | — |
| 2019 | 4.5 | 43.0% | — |
| 2020 | 1.9 | 17.7% | — |
| 2021 | 3.9 | 37.4% | — |
| 2022 | 4.1 | 39.2% | — |
| 2023 | 3.8 | 36.5% | — |
| 2024 | 2.6 | 24.6% | — |
| 2025 | 1.8 | 17.4% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| GEN1 | Conventional Hydroelectric | HY | 0.4 | 0.4 | Jan 1914 | Operating | — | coming soon |
| GEN2 | Conventional Hydroelectric | HY | 0.4 | 0.4 | Jan 1914 | Operating | — | coming soon |
| GEN3 | Conventional Hydroelectric | HY | 0.4 | 0.4 | Jan 1914 | Operating | — | coming soon |
Owner / operator
Operator: Energen Renewables, LLC. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Energen Renewables, LLC | 100.0% | 1 MW |
Nearby plants
Within 80 km.
| Sewalls | 2 MW | 0.7 km |
| Watertown | 8 MW | 1 km |
| Beebee Island Hydro Plant | 9 MW | 1.7 km |
| OYA Wayside Drive | 5 MW | 5.1 km |
| St. Lawrence University - Sutton | 2 MW | 5.3 km |
| Black River | 6 MW | 6.3 km |