How many hydroelectric power plants are in Hawaii?

8, with 35 MW of nameplate capacity between them, spread over 3 counties. That is the EIA-860M operating count for 2026-07.

Is there a map of Hawaii hydroelectric power plants?

Yes — the map above. Each dot is one hydroelectric power plant, sized by nameplate capacity and placed at the coordinates EIA files for it.

Which is the largest hydroelectric power plant in Hawaii?

Wailuku River Hydroelectric, at 10 MW. The table is sorted largest first, so the rest follow it.

Is there a hydroelectric power plant near me in Hawaii?

The county roll-up below groups every plant by county, which is the quickest way to find the one closest to a given town.

Which grid operator runs Hawaii's hydroelectric power plants?

No single ISO or RTO covers most of them. EIA files each plant against its own balancing authority, which in Hawaii is largely a vertically integrated utility rather than an organised market.

How current is this, and what is left out?

EIA-860M for 2026-07. Conventional hydroelectric. Pumped storage is counted separately. Plants below 1 MW are not surveyed by EIA and so are absent; retirements and additions after 2026-07 arrive with the next monthly release.

Hydroelectric Power Plants in Hawaii

Every operating hydroelectric power plant in Hawaii on EIA-860M for 2026-07: 8 plants, 17 generating units and 35 MW of nameplate capacity across 3 counties.

As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m

Plants: 8; 17 generating units
Nameplate capacity: 35 MW
Counties: 3
Grid operator: Mixed; no single ISO covers a majority

Map of hydroelectric power plants in Hawaii

Every one of the 8 plants is drawn at the coordinate EIA files for it.

Loading map…

Hydro · 8

List of hydroelectric power plants in Hawaii

Sort by any column. Capacity is nameplate, summed across every generating unit EIA lists at the site.

hydroelectric power plants in Hawaii

Wailuku River HydroelectricConventional Hydroelectric	Wailuku Holding Company LLC	Hawaii	10.4	2	1993	Operating
Gay Robinson2 technologies	Gay & Robinson Inc	Kauai	8.7	4	1982	Standby/Backup
Kaheka HydroConventional Hydroelectric	Mahi Pono LLC	Maui	4.5	3	1925	Out of service and NOT expected to return to service in next calendar year
Wainiha HydroConventional Hydroelectric	BBCP Kauai Operating LLC	Kauai	3.6	2	1906	Operating
PuueoConventional Hydroelectric	Hawaii Electric Light Co Inc	Hawaii	3.1	2	1918	Operating
Kalaheo HydroConventional Hydroelectric	BBCP Kauai Operating LLC	Kauai	2	1	2016	Operating
Paia Hydroelectric PlantConventional Hydroelectric	Mahi Pono LLC	Maui	1.3	1	1912	Out of service and NOT expected to return to service in next calendar year
Waiau HydroConventional Hydroelectric	Hawaii Electric Light Co Inc	Hawaii	1	2	1921	Operating

Largest hydroelectric power plants in Hawaii

1Wailuku River HydroelectricHawaii County, Hawaii10.4 MW
2Gay RobinsonKauai County, Hawaii8.7 MW
3Kaheka HydroMaui County, Hawaii4.5 MW
4Wainiha HydroKauai County, Hawaii3.6 MW
5PuueoHawaii County, Hawaii3.1 MW
6Kalaheo HydroKauai County, Hawaii2 MW
7Paia Hydroelectric PlantMaui County, Hawaii1.3 MW
8Waiau HydroHawaii County, Hawaii1 MW

Hydroelectric power plants by county in Hawaii

The county EIA files against each plant. It is the fastest way to find the plant nearest a given town.

County	Plants	Nameplate MW
Hawaii	3	14.5
Kauai	3	14.3
Maui	2	5.8

Hydroelectric Power Plants in Hawaii: FAQ

How many hydroelectric power plants are in Hawaii?: 8, with 35 MW of nameplate capacity between them, spread over 3 counties. That is the EIA-860M operating count for 2026-07.
Is there a map of Hawaii hydroelectric power plants?: Yes — the map above. Each dot is one hydroelectric power plant, sized by nameplate capacity and placed at the coordinates EIA files for it.
Which is the largest hydroelectric power plant in Hawaii?: Wailuku River Hydroelectric, at 10 MW. The table is sorted largest first, so the rest follow it.
Is there a hydroelectric power plant near me in Hawaii?: The county roll-up below groups every plant by county, which is the quickest way to find the one closest to a given town.
Which grid operator runs Hawaii's hydroelectric power plants?: No single ISO or RTO covers most of them. EIA files each plant against its own balancing authority, which in Hawaii is largely a vertically integrated utility rather than an organised market.
How current is this, and what is left out?: EIA-860M for 2026-07. Conventional hydroelectric. Pumped storage is counted separately. Plants below 1 MW are not surveyed by EIA and so are absent; retirements and additions after 2026-07 arrive with the next monthly release.