Bear Swamp
Berkshire County, Massachusetts · EIA plant ID 8005 · Operator: Bear Swamp Power Company LLC
Nameplate666MWSummer 666 MW
Generators2in service
Net generation-212GWh12 mo to Aug 2026
Capacity factor—not meaningful for storage
Heat rate—thermal plants only
First online1974
The 12-month figures include preliminary EIA-923 months, which EIA revises. Final data runs through Dec 2025.
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.
No capacity factor available.
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 | -159.1 | — | — |
| 2002 | -330.4 | — | — |
| 2003 | -117.9 | — | — |
| 2004 | -120.7 | — | — |
| 2005 | -132.6 | — | — |
| 2006 | -207.6 | — | — |
| 2007 | -250.7 | — | — |
| 2008 | -338.4 | — | — |
| 2009 | -162.8 | — | — |
| 2010 | -181 | — | — |
| 2011 | -143.6 | — | — |
| 2012 | -100.9 | — | — |
| 2013 | -145.6 | — | — |
| 2014 | -148.5 | — | — |
| 2015 | -160 | — | — |
| 2016 | -151.4 | — | — |
| 2017 | -103.2 | — | — |
| 2018 | -171 | — | — |
| 2019 | -163.7 | — | — |
| 2020 | -140.3 | — | — |
| 2021 | -150.7 | — | — |
| 2022 | -129.3 | — | — |
| 2023 | -198.4 | — | — |
| 2024 | -212.4 | — | — |
| 2025 | -154.4 | — | — |
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 | Hydroelectric Pumped Storage | PS | 333 | 333 | Sep 1974 | Operating | — | coming soon |
| GEN2 | Hydroelectric Pumped Storage | PS | 333 | 333 | Oct 1974 | Operating | — | coming soon |
Owner / operator
Operator: Bear Swamp Power Company LLC. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Emera Inc | 50.0% | 333 MW |
| Bear Swamp Power Company LLC | 50.0% | 333 MW |
Nearby plants
Within 80 km.
| Deerfield 5 | 18 MW | 0.9 km |
| Fife Brook | 11 MW | 1.5 km |
| Sherman | 7 MW | 5.6 km |
| Fairhaven E | 2 MW | 7 km |
| Charlemont A | 5 MW | 7 km |
| New England Wind LLC | 29 MW | 7.3 km |