Waiau Hydro
Hawaii County, Hawaii · EIA plant ID 774 · Operator: Hawaii Electric Light Co Inc
Nameplate1MWSummer 1 MW
Generators2in service
Net generation0GWh12 mo to Aug 2026
Capacity factor0%hydro units, summer MW
Heat rate—thermal plants only
First online1921
The 12-month figures include preliminary EIA-923 months, which EIA revises. Final data runs through Dec 2025.
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 | 5.3 | 60.0% | — |
| 2002 | 0.5 | 5.3% | — |
| 2003 | 2.1 | 24.3% | — |
| 2004 | 6.3 | 71.5% | — |
| 2005 | 3.6 | 41.4% | — |
| 2006 | 6.8 | 77.2% | — |
| 2007 | 6.4 | 73.3% | — |
| 2008 | 5.8 | 66.2% | — |
| 2009 | 8.2 | 93.5% | — |
| 2010 | 4.6 | 52.8% | — |
| 2011 | 4.1 | 47.3% | — |
| 2012 | 7.9 | 90.3% | — |
| 2013 | 5.1 | 58.5% | — |
| 2014 | 6.8 | 77.6% | — |
| 2015 | 6 | 68.2% | — |
| 2016 | 3.4 | 38.4% | — |
| 2017 | 4.3 | 48.5% | — |
| 2018 | 4.3 | 49.4% | — |
| 2019 | 0 | 0.0% | — |
| 2020 | 0 | 0.0% | — |
| 2021 | 0 | 0.0% | — |
| 2022 | 0 | 0.0% | — |
| 2023 | 0 | 0.0% | — |
| 2024 | 0 | 0.0% | — |
| 2025 | 0 | 0.0% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| 1 | Conventional Hydroelectric | HY | 0.7 | 0.7 | Dec 1921 | Operating | — | coming soon |
| 2 | Conventional Hydroelectric | HY | 0.3 | 0.3 | Dec 1928 | Operating | — | coming soon |
Owner / operator
Operator: Hawaii Electric Light Co Inc. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Hawaii Electric Light Co Inc | 100.0% | 1 MW |
Nearby plants
Within 80 km.
| Puueo | 3 MW | 3 km |
| Wailuku River Hydroelectric | 10 MW | 3.2 km |
| Kanoelehua | 21 MW | 6.1 km |
| W H Hill | 37 MW | 6.4 km |
| Puna | 39 MW | 13.5 km |
| Mauna Loa Macadamia Nut | 1 MW | 13.5 km |