Happy Hollow CSG Hybrid
Worcester County, Massachusetts · EIA plant ID 62652 · Operator: REA Investments, LLC
Nameplate8MWSummer 8 MW
Generators2in service
Net generation8GWh12 mo to Dec 2025
Capacity factor19%solar units, summer MW
Heat rate—thermal plants only
First online2019
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), solar 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.
Heat rate applies to fuel-burning (thermal) units only.
Annual data table
| Year | Net GWh | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|
| 2019 | 1 | 8.9% | — |
| 2020 | 8.3 | 18.8% | — |
| 2021 | 7.9 | 18.0% | — |
| 2022 | 8.6 | 19.7% | — |
| 2023 | 8 | 18.2% | — |
| 2024 | 8.6 | 20.1% | — |
| 2025 | 8.1 | 19.1% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| HHESS | Batteries | BA | 3.3 | 3.3 | Oct 2019 | Operating | — | coming soon |
| HHPV | Solar Photovoltaic | PV | 5 | 5 | Oct 2019 | Operating | — | coming soon |
Owner / operator
Operator: REA Investments, LLC. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Happy Hollow Solar Holdings, LLC | 100.0% | 8 MW |
Nearby plants
Within 80 km.
| Gardner - Otter River Road | 3 MW | 0.7 km |
| West Street Solar 1 LLC | 5 MW | 1.3 km |
| Clark Road Solar 1, LLC | 8 MW | 2.4 km |
| Gardner Solar 1 | 2 MW | 2.6 km |
| Mt Wachusett Community College | 3 MW | 5.4 km |
| Winchendon Solar | 2 MW | 7.3 km |