Gilman Mill
Essex County, Vermont · EIA plant ID 10608 · Operator: Ampersand Gilman Hydro LP
Nameplate5MWSummer 4 MW
Generators4in service
Net generation2GWh12 mo to Dec 2025
Capacity factor6%hydro units, summer MW
Heat rate—thermal plants only
First online1941
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), hydro 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) |
|---|---|---|---|
| 2001 | 35.3 | 39.9% | — |
| 2002 | 19.5 | 40.1% | — |
| 2003 | 6.1 | 15.2% | — |
| 2004 | 26.6 | 52.4% | — |
| 2005 | 30 | 52.9% | — |
| 2006 | 25.2 | 54.1% | — |
| 2007 | 1.5 | 3.8% | — |
| 2008 | 21.1 | 52.2% | — |
| 2009 | 25 | 66.3% | — |
| 2010 | 25.3 | 67.2% | — |
| 2011 | 23.9 | 63.4% | — |
| 2012 | 23.3 | 61.6% | — |
| 2013 | 24.9 | 66.1% | — |
| 2014 | 23.2 | 61.6% | — |
| 2015 | 22.4 | 59.5% | — |
| 2016 | 24.6 | 65.0% | — |
| 2017 | 25 | 66.5% | — |
| 2018 | 24.5 | 65.0% | — |
| 2019 | 22.6 | 59.9% | — |
| 2020 | 22.4 | 59.3% | — |
| 2021 | 19.4 | 51.4% | — |
| 2022 | 23 | 61.1% | — |
| 2023 | 28.1 | 74.7% | — |
| 2024 | 3.9 | 10.2% | — |
| 2025 | 2.2 | 5.8% | — |
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 | Conventional Hydroelectric | HY | 2.2 | 2.1 | Mar 1986 | Operating | — | coming soon |
| GEN2 | Conventional Hydroelectric | HY | 1 | 0.9 | Jan 1966 | Operating | — | coming soon |
| GEN3 | Conventional Hydroelectric | HY | 0.8 | 0.7 | Jan 1941 | Operating | — | coming soon |
| GEN4 | Conventional Hydroelectric | HY | 0.8 | 0.6 | Jan 1941 | Operating | — | coming soon |
| GEN5 | Wood/Wood Waste Biomass | ST | 4 | 3.7 | Feb 1982 | Retired Jan 2014 | — | coming soon |
Owner / operator
Operator: Ampersand Gilman Hydro LP. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Ampersand Gilman Hydro LP | 100.0% | 5 MW |
Nearby plants
Within 80 km.
| GSPP Gilman, LLC | 2 MW | 0.7 km |
| Pinetree Power | 18 MW | 10 km |
| S C Moore | 195 MW | 14.7 km |
| DG Whitefield LLC | 20 MW | 15.4 km |
| Golden Solar | 2 MW | 19.9 km |
| Great Falls (VT) | 2 MW | 24 km |