Deer Island Treatment Plant
Suffolk County, Massachusetts · EIA plant ID 10823 · Operator: Massachusetts Wtr RAuth-Deer I
Nameplate73MWSummer 56 MW
Generators8in service
Net generation32GWh12 mo to Aug 2026
Capacity factor1%gas/coal/oil units, summer MW
Heat rate4,133Btu/kWhfossil units, electric fuel, HHV
First online1995Runs as rarely runs
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), 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 | 34.5 | — | — |
| 2002 | 33.5 | — | — |
| 2003 | 15.7 | 0.5% | 11,658 |
| 2004 | 34.5 | 4.0% | 10,765 |
| 2005 | 45.1 | 5.2% | 12,027 |
| 2006 | 41.7 | 2.4% | 11,610 |
| 2007 | 36.8 | 1.2% | 11,750 |
| 2008 | 35.6 | 7.2% | — |
| 2009 | 35.9 | 6.6% | — |
| 2010 | 37 | 7.4% | 7,615 |
| 2011 | 26.7 | 3.9% | — |
| 2012 | 24.2 | 4.0% | — |
| 2013 | 24.1 | 4.1% | 4,500 |
| 2015 | 28.4 | 5.1% | — |
| 2016 | 39.8 | 1.6% | 4,135 |
| 2017 | 43.3 | 2.1% | 4,103 |
| 2018 | 44.2 | 1.9% | 4,108 |
| 2019 | 43.4 | 2.4% | 4,101 |
| 2020 | 36.5 | 1.0% | 4,113 |
| 2021 | 37.3 | 0.9% | 4,116 |
| 2022 | 35.5 | 0.8% | 4,129 |
| 2023 | 35.4 | 0.8% | 4,111 |
| 2024 | 37 | 1.5% | 4,118 |
| 2025 | 33.4 | 1.0% | 4,128 |
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 |
|---|---|---|---|---|---|---|---|---|
| G101 | Petroleum Liquids | GT | 26 | 22 | Aug 1995 | Operating (Standby / backup) | — | coming soon |
| G201 | Petroleum Liquids | GT | 26 | 22 | Aug 1995 | Operating (Standby / backup) | — | coming soon |
| H101 | Conventional Hydroelectric | HY | 1 | 1 | Jul 2001 | Operating | — | coming soon |
| H201 | Conventional Hydroelectric | HY | 1 | 1 | Jul 2001 | Operating | — | coming soon |
| PV101 | Solar Photovoltaic | PV | 0.1 | 0.1 | May 2008 | Operating | — | coming soon |
| S101 | Other Waste Biomass | ST | 17.5 | 9 | Jul 1998 | Operating | — | coming soon |
| WT101 | Onshore Wind Turbine | WT | 0.6 | 0.6 | Nov 2009 | Operating | — | vestas PS-600 |
| WT102 | Onshore Wind Turbine | WT | 0.6 | 0.6 | Nov 2009 | Operating | — | vestas PS-600 |
| 6ENT | Other Waste Biomass | IC | 6 | 6 | Dec 1989 | Retired Mar 2004 | — | coming soon |
| 7ENT | Other Waste Biomass | IC | 6 | 6 | Dec 1989 | Retired Mar 2004 | — | coming soon |
| F101 | Other Waste Biomass | FC | 0.2 | 0.2 | Aug 1997 | Retired Dec 2001 | — | coming soon |
Owner / operator
Operator: Massachusetts Wtr RAuth-Deer I. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Massachusetts Wtr RAuth-Deer I | 100.0% | 73 MW |
Nearby plants
Within 80 km.
| M Street Jet | 69 MW | 5.8 km |
| Energizar BESS | — | 6.8 km |
| UMass Boston | 8 MW | 7.5 km |
| Gillette SBMC | 14 MW | 7.7 km |
| Signature Breads Chelsea | 2 MW | 8.2 km |
| Boston Scientific Solar | 1 MW | 8.9 km |