22nd largest plant in Massachusetts · 2614th nationally
Semass Resource Recovery is a biomass power plant in Massachusetts with a nameplate capacity of 98.5 MW. It generates roughly 594.1k MWh per year — enough to power about 56,579 average U.S. homes.
Its capacity factor of 69% puts it in the middle range — running steadily but not full-time. At 2004 lb CO₂/MWh, its emission rate sits above the national grid average of roughly 800 lb/MWh.
Ghost bars are each month's theoretical maximum (98.5 MW nameplate × hours in the month). Filled bars are actual net generation reported to EIA Form 923. The gap between them is capacity factor made visible.
| Plant Name | Semass Resource Recovery |
|---|---|
| Operator | Semass Partnership |
| City | West Wareham |
| County | Plymouth County |
| State | Massachusetts |
| ZIP | 02576 |
| Coordinates | 41.80220, -70.78750 |
This plant highlighted in navy-ringed pin; other generators within 25 miles shown as fuel-colored dots.
| ID | Technology | Fuel | Capacity | Status | Online |
|---|---|---|---|---|---|
| GEN1 | Municipal Solid Waste | Municipal Waste | 64.5 MW | Operating | 1988 |
| GEN2 | Municipal Solid Waste | Municipal Waste | 34.0 MW | Operating | 1993 |
| CO₂ | 595.3k metric tons |
|---|---|
| SO₂ | 903 metric tons |
| NOₓ | 1.7k metric tons |
| CO₂ Rate | 2004 lb/MWh |
Annual totals and CO₂ rate reported by EPA eGRID for 2023. Reference averages are approximate U.S.-wide figures from the same dataset.
| NERC Region | NPCC |
|---|---|
| Balancing Authority | Iso New England Inc. |
Biomass plants burn wood, agricultural waste, or methane from landfills to generate steam and electricity. They are considered carbon-neutral over long timescales when fuel is sustainably sourced, but they produce particulate emissions similar to coal.