SEMASS Resource Recovery
Plymouth County, Massachusetts · EIA plant ID 50290 · Operator: SEMASS Partnership
Nameplate99MWSummer 80 MW
Generators2in service
Net generation537GWh12 mo to Aug 2026
Capacity factor75%other units, summer MW
Heat rate18,793Btu/kWhfossil units, electric fuel, HHV
First online1988
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), other 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 | 611.7 | 90.7% | — |
| 2002 | 594.3 | 84.8% | — |
| 2003 | 590.6 | 84.3% | — |
| 2004 | 590 | 84.0% | — |
| 2005 | 576 | 82.2% | — |
| 2006 | 594.7 | 84.9% | — |
| 2007 | 554.6 | 79.1% | — |
| 2008 | 590.4 | 83.6% | 18,792 |
| 2009 | 553.6 | 78.2% | 19,279 |
| 2010 | 584.4 | 82.8% | 19,055 |
| 2011 | 589.5 | 83.7% | 20,021 |
| 2012 | 600.7 | 85.0% | 18,291 |
| 2013 | 588.8 | 83.9% | 19,138 |
| 2014 | 603.9 | 86.0% | 19,021 |
| 2015 | 587.6 | 83.2% | 18,663 |
| 2016 | 588.5 | 83.0% | 18,551 |
| 2017 | 584.3 | 82.4% | 18,807 |
| 2018 | 568.2 | 80.3% | 18,963 |
| 2019 | 583.7 | 82.6% | 18,496 |
| 2020 | 550.4 | 77.5% | 19,475 |
| 2021 | 593.1 | 83.9% | 18,194 |
| 2022 | 590.3 | 83.4% | 18,049 |
| 2023 | 594.1 | 83.9% | 18,060 |
| 2024 | 568.1 | 79.6% | 18,694 |
| 2025 | 567.1 | 79.5% | 18,259 |
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 | Municipal Solid Waste | ST | 64.5 | 53.3 | Jul 1988 | Operating | — | coming soon |
| GEN2 | Municipal Solid Waste | ST | 34 | 26.7 | Apr 1993 | Operating | — | coming soon |
Owner / operator
Operator: SEMASS Partnership. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| SEMASS Partnership | 100.0% | 99 MW |
Nearby plants
Within 80 km.
| Old Middleboro Road Solar | 10 MW | 2.9 km |
| Acushnet AD Makepeace | 4 MW | 3.7 km |
| Syncarpha Freetown | 4 MW | 3.7 km |
| Solar Carver 1 Hybrid | — | 3.8 km |
| 71 Charlotte Furnace Rd Hybrid(CSG) | 2 MW | 3.8 km |
| Cranberry Highway Solar LLC | 4 MW | 3.9 km |