Groton BESS 1
Middlesex County, Massachusetts · EIA plant ID 67185 · Operator: Groton BESS 1 LLC
Nameplate2MWSummer 2 MW
Generators1in service
Net generation-0GWh12 mo to Dec 2025
Capacity factor—not meaningful for storage
Heat rate—thermal plants only
First online2024
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) |
|---|---|---|---|
| 2024 | -0.1 | — | — |
| 2025 | -0.3 | — | — |
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 |
|---|---|---|---|---|---|---|---|---|
| 90911 | Batteries | BA | 2 | 2 | Aug 2024 | Operating | — | coming soon |
Owner / operator
Operator: Groton BESS 1 LLC. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Groton BESS 1 LLC | 100.0% | 2 MW |
Nearby plants
Within 80 km.
| Groton BESS 2 | 2 MW | 3.2 km |
| Dunstable Solar 1, LLC | 9 MW | 6.5 km |
| Nextsun Energy Littleton | 4 MW | 6.8 km |
| Pepperell Hydro Power Plant | 2 MW | 7.3 km |
| West Groton CHP | 4 MW | 7.8 km |
| GSPP Devens, LLC | 2 MW | 8.2 km |