Tunnel
New London County, Connecticut · EIA plant ID 557 · Operator: FirstLight Power Resources Services LLC
Nameplate21MWSummer 18 MW
Generators3in service
Net generation6GWh12 mo to Dec 2025
Capacity factor0%gas/coal/oil units, summer MW
Heat rate—Btu/kWhfossil units, electric fuel, HHV
First online1919Runs as rarely runs
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), gas/coal/oil 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 | 6.5 | — | — |
| 2002 | 6.2 | — | — |
| 2003 | 11.2 | 0.4% | 14,952 |
| 2004 | 9.5 | 0.7% | 16,152 |
| 2005 | 12.2 | 1.1% | 15,901 |
| 2006 | 9.1 | 0.6% | 17,190 |
| 2007 | 6.8 | 0.3% | — |
| 2008 | 10.9 | 0.4% | 13,856 |
| 2009 | 11.4 | 0.2% | 13,780 |
| 2010 | 7.3 | 0.3% | 13,960 |
| 2011 | 12.8 | 0.4% | 13,102 |
| 2012 | 7.4 | 0.1% | 14,169 |
| 2013 | 8.3 | 0.2% | 14,264 |
| 2014 | 7.7 | 0.1% | 13,758 |
| 2015 | 5.6 | 0.3% | 12,085 |
| 2016 | 6.1 | 0.1% | 15,287 |
| 2017 | 10.6 | 0.3% | 15,420 |
| 2018 | 11 | 0.2% | 15,423 |
| 2019 | 9.4 | 0.2% | 15,663 |
| 2020 | 8.5 | 0.4% | 16,150 |
| 2021 | 11.2 | 0.1% | 15,043 |
| 2022 | 7.3 | 0.1% | 15,302 |
| 2023 | 11.9 | 0.1% | 14,877 |
| 2024 | 7.7 | 0.0% | — |
| 2025 | 5.9 | 0.0% | — |
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 | 1 | 0.8 | Jan 1919 | Operating | — | coming soon |
| 10 | Petroleum Liquids | GT | 18.5 | 16.5 | Jan 1969 | Operating (Standby / backup) | — | coming soon |
| 2 | Conventional Hydroelectric | HY | 1 | 0.8 | Jan 1949 | 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% | 21 MW |
Nearby plants
Within 80 km.
| Taftville | 2 MW | 1.9 km |
| Tenth Street | 1 MW | 2 km |
| Wheelabrator Lisbon | 15 MW | 3.2 km |
| North Main Street | retired | 3.7 km |
| Backus Microgrid Project | 10 MW | 4.5 km |
| Norwich WWTP | 2 MW | 4.8 km |