Wanapum

Hydro power plant · Grant County, Washington

Nameplate capacity
1,220 MW
Rank in Washington
#4
of 139 plants
In service since
2011
April 2011

Details

Primary fuel
Hydro
Technology
Conventional Hydroelectric
Operator
PUD No 2 of Grant County
County
Grant County
Generating units
10
Share of state capacity
3.85%
Rank among hydro plants in Washington
#4 of 73
EIA plant code
3888

Generating units

Individual generating units at Wanapum
UnitTechnologyNameplateSummerOnlineStatus
10AConventional Hydroelectric122 MW122 MW2014Operating
1AConventional Hydroelectric122 MW122 MW2013Operating
2AConventional Hydroelectric122 MW122 MW2012Operating
3AConventional Hydroelectric122 MW122 MW2017Operating
4AConventional Hydroelectric122 MW122 MW2020Operating
5AConventional Hydroelectric122 MW122 MW2012Operating
6AConventional Hydroelectric122 MW122 MW2016Operating
7AConventional Hydroelectric122 MW122 MW2011Operating
8AConventional Hydroelectric122 MW122 MW2018Operating
9AConventional Hydroelectric122 MW122 MW2015Operating

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 Washington

Chief JosephHydro2,456 MW
Rocky ReachHydro1,349 MW
Columbia Generating StationNuclear1,200 MW
BoundaryHydro1,160 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 1,220 MW solar plant and a 1,220 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 Washington power plants · What Washington actually generates