Diamond Island Plant
Hydro power plant · Jefferson County, New York
Nameplate capacity
1.2 MW
Rank in New York
#1105
of 1,152 plants
In service since
1914
January 1914
Details
- Primary fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Operator
- —
- County
- Jefferson County
- Generating units
- 3
- Share of state capacity
- 0.00%
- Rank among hydro plants in New York
- #154 of 165
- EIA plant code
- 10540
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| GEN1 | Conventional Hydroelectric | 0.4 MW | 0.4 MW | 1914 | Operating |
| GEN2 | Conventional Hydroelectric | 0.4 MW | 0.4 MW | 1914 | Operating |
| GEN3 | Conventional Hydroelectric | 0.4 MW | 0.4 MW | 1914 | Operating |
Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.
Similarly sized plants in New York
| Theresa Plant | Hydro | 1.3 MW |
| Calabro Airport South Solar Project | Solar | 1.2 MW |
| Holtsville Solar Project | Solar | 1.2 MW |
| Interfaith Medical Center | Other | 1.2 MW |
About this data
From EIA’s inventory of operable generators, June 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 1.2 MW solar plant and a 1.2 MW nuclear plant have the same entry here and produce very different amounts of electricity.
“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All New York power plants · What New York actually generates