Waiau

Other power plant · Honolulu County, Hawaii

Nameplate capacity
375 MW
Rank in Hawaii
#2
of 76 plants
In service since
1959
September 1959

Details

Primary fuel
Other
Technology
Petroleum Liquids
Operator
Hawaiian Electric Co Inc
County
Honolulu County
Generating units
6
Share of state capacity
10.15%
Rank among other plants in Hawaii
#2 of 25
EIA plant code
766

Generating units

Individual generating units at Waiau
UnitTechnologyNameplateSummerOnlineStatus
W7Petroleum Liquids82 MW78 MW1966Operating
W8Petroleum Liquids82 MW78 MW1968Operating
W5Petroleum Liquids54 MW52 MW1959Operating
W6Petroleum Liquids54 MW52 MW1961Operating
W10Petroleum Liquids51 MW51 MW1973Operating
W9Petroleum Liquids51 MW51 MW1973Operating

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 Hawaii

KaheOther610 MW
Kalaeloa Cogen PlantOther299 MW
MaalaeaOther230 MW

About this data

From EIA’s inventory of operable generators, May 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 375 MW solar plant and a 375 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 Hawaii power plants · What Hawaii actually generates