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Black Walnut Energy Storage LLC

Battery storage power plant · Ventura County, California

Nameplate capacity
15 MW
Rank in California
#754
of 1,897 plants
In service since
2025
October 2025

Details

Primary fuel
Battery storage
Technology
Batteries
Operator
Black Walnut Energy Storage LLC
County
Ventura County
Generating units
1
Share of state capacity
0.01%
Rank among battery storage plants in California
#83 of 142
EIA plant code
65396

Generating units

Individual generating units at Black Walnut Energy Storage LLC
UnitTechnologyNameplateSummerOnlineStatus
BW1Batteries15 MW15 MW2025Operating

Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.

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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 15 MW solar plant and a 15 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 California power plants · What California actually generates