Shepaug
New Haven County, Connecticut · EIA plant ID 552 · Operator: FirstLight Power Resources Services LLC
Nameplate37MWSummer 42 MW
Generators1in service
Net generation93GWh12 mo to Dec 2025
Capacity factor26%hydro units, summer MW
Heat rate—thermal plants only
First online1955
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 | 73.4 | 23.7% | — |
| 2002 | 91.3 | 25.1% | — |
| 2003 | 175.6 | 48.3% | — |
| 2004 | 140.6 | 38.6% | — |
| 2005 | 148.3 | 40.8% | — |
| 2006 | 165.2 | 45.4% | — |
| 2007 | 111.2 | 30.6% | — |
| 2008 | 173.1 | 47.5% | — |
| 2009 | 148.4 | 40.8% | — |
| 2010 | 122.3 | 33.7% | — |
| 2011 | 184.3 | 50.7% | — |
| 2012 | 90.2 | 24.8% | — |
| 2013 | 126.9 | 34.9% | — |
| 2014 | 145.2 | 39.9% | — |
| 2015 | 96.2 | 26.5% | — |
| 2016 | 72.7 | 20.0% | — |
| 2017 | 103.5 | 28.5% | — |
| 2018 | 187.8 | 51.7% | — |
| 2019 | 143.1 | 39.4% | — |
| 2020 | 107 | 29.3% | — |
| 2021 | 148.3 | 40.8% | — |
| 2022 | 99.7 | 27.4% | — |
| 2023 | 163.1 | 44.9% | — |
| 2024 | 116.6 | 32.0% | — |
| 2025 | 93.3 | 25.7% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| 1 | Conventional Hydroelectric | HY | 37.2 | 41.5 | Jan 1955 | Operating | — | coming soon |
Owner / operator
Operator: FirstLight Power Resources Services LLC. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| FirstLight Hydro Generating Company | 100.0% | 37 MW |
Nearby plants
Within 80 km.
| IBM Southbury | retired | 7.8 km |
| Stevenson | 31 MW | 12.6 km |
| TRS Fuel Cell | 4 MW | 13.3 km |
| Danbury Hospital Cogen Plant | 4 MW | 13.6 km |
| CPV Towantic Energy Center | 842 MW | 14.8 km |
| New Milford Gas Recovery | 2 MW | 15.5 km |