99 Islands
Hydro power plant in Cherokee County, South Carolina. 12 MW of nameplate capacity across 4 generators, operated by Duke Energy Carolinas, LLC.
Also known as 99 Island Dam · EIA plant 3272
Analyst: free account, 1 question a day.
Key facts
- Capacity
- 12 MWNameplate
- Generators
- 4 operatingEIA-860M, August 2026
- Operating since
- May 1910First generator online
- Operator
- Duke Energy Carolinas, LLCEIA operator ID 5416
- Grid
- DUKBalancing authority DUK
- Price nodes
- None linkedNo verified ISO node
- Location
- Cherokee County, SC35.0314, −81.4936
- EIA plant ID
- 3272EIA plant page
Data as of EIA-860M August 2026 (published 2026-09-24). Capacity is nameplate, not live output.
How much power 99 Islands produces
Free · EIA-923Net generation, 2025
31.3 GWh
31,276 MWh, final
Capacity factor, 2025
29.8%
2024: 34.6%
January to July 2026
Not reported
Provisional. 0 of 7 months reported
Range, 2015 to 2025
31.3–83.3
GWh a year. Low 2025, high 2018
| Year | Net generation, MWh | Capacity factor | Months reported |
|---|---|---|---|
| 2000 | 32,771 | Not reported | 12 of 12 |
| 2001 | 25,383 | Not reported | 12 of 12 |
| 2002 | 29,352 | Not reported | 12 of 12 |
| 2003 | 63,162 | Not reported | 12 of 12 |
| 2004 | 53,365 | Not reported | 12 of 12 |
| 2005 | 38,926 | Not reported | 12 of 12 |
| 2006 | 5,638 | Not reported | 12 of 12 |
| 2007 | 37,550 | Not reported | 12 of 12 |
| 2008 | 33,713 | Not reported | 12 of 12 |
| 2009 | 62,370 | Not reported | 12 of 12 |
| 2010 | 69,862 | 44.3% | 12 of 12 |
| 2011 | 50,740 | 32.2% | 12 of 12 |
| 2012 | 49,577 | 31.4% | 12 of 12 |
| 2013 | 91,592 | 58.1% | 12 of 12 |
| 2014 | 78,817 | 50.0% | 12 of 12 |
| 2015 | 61,397 | 38.9% | 12 of 12 |
| 2016 | 45,196 | 28.6% | 12 of 12 |
| 2017 | 50,585 | 32.1% | 12 of 12 |
| 2018 | 83,267 | Not reported | 12 of 12 |
| 2019 | 67,604 | 64.3% | 12 of 12 |
| 2020 | 80,306 | 76.2% | 12 of 12 |
| 2021 | 61,191 | 58.2% | 12 of 12 |
| 2022 | 45,348 | 43.1% | 12 of 12 |
| 2023 | 62,087 | 59.1% | 12 of 12 |
| 2024 | 36,505 | 34.6% | 12 of 12 |
| 2025 | 31,276 | 29.8% | 12 of 12 |
| 2026 (provisional, partial year) | Not reported | Not reported | 0 of 7 |
* 2026 covers January to July and is provisional. Capacity factor is net generation divided by nameplate capacity times the hours of each reported month.
Power prices and basis
Free accountNo verified ISO price node is linked to this plant, or its price history could not load.
Emissions
Free · EPA CAMPDNo EPA emissions units are linked to this plant.
Water use
Free · EIA-923 cooling, USGSNo EIA cooling-water record for this plant in 2024. Plants without steam cooling, such as wind, solar and batteries, do not report cooling water.
Generators
Free · EIA-860M| Generator | Technology | Nameplate MW | Online since |
|---|---|---|---|
| 1 | Conventional Hydroelectric | 3.0 | May 1910 |
| 2 | Conventional Hydroelectric | 3.0 | May 1910 |
| 3 | Conventional Hydroelectric | 3.0 | May 1910 |
| 4 | Conventional Hydroelectric | 3.0 | May 1910 |
Ownership and offtake
ProOwnership and offtake are part of Pro
Owners and their shares, parent companies, and power purchase agreements with their buyers. EIA-860M lists Duke Energy Carolinas, LLC as the operator, which is not always the owner.
Modeled data
ProPro adds modeled values for this plant. Everything above stays free.
300 analyst questions a month, plus MCP
Query 99 Islands and 14,224 other projects from Claude or your own tools. Free accounts get 1 question a day.
Power plants near 99 Islands
More plants operated by Duke Energy Carolinas, LLC
Questions about 99 Islands
How much power does 99 Islands produce?
99 Islands reported 31,276 MWh (31.3 GWh) of net generation in 2025, a 29.8% capacity factor on 12 MW of nameplate capacity.
Where is 99 Islands?
99 Islands is in Cherokee County, South Carolina, at 35.0314, −81.4936. It is in the Duke Energy Carolinas balancing area (DUK).
Who operates 99 Islands?
EIA-860M for August 2026 lists Duke Energy Carolinas, LLC as the operator (EIA operator ID 5416). The operator is not always the owner.
When did 99 Islands start operating?
Its first generator began operating in May 1910, according to EIA-860M.
Sources
- EIA-860 2025 (final) and EIA-860M August 2026: plant, generators, capacity, operator and location
- EIA-923 monthly net generation, 2000 to July 2026 (2026 provisional)
- Plant names from OpenStreetMap, © OpenStreetMap contributors (ODbL)
Page updated 2026-10-04 from the InfraMap data build. Methodology · Data sources · EIA plant page