Compare power plants

Registry, engineering, and operating metrics shown on a consistent EIA basis.

Metric	Mammoth Pool Madera County	J S Eastwood Fresno County
Capacity	190 MW	199.8 MW
Technology	Conventional Hydroelectric	Hydroelectric Pumped Storage
Operator	Southern California Edison Co	Southern California Edison Co
Operating units	2	1
Latest 12-month generation	571.5 GWh	203.9 GWh
Latest complete-year capacity factor	28.0% (2025)	—
National technology rank	#73 of 1,349	#27 of 39
Latest EIA report	2026-06	2026-06

Generation comes from EIA-923. Capacity, unit counts, technology, and reporting relationships come from EIA-860. Incomplete reporting years are excluded from capacity-factor comparisons.

Compare power plants

Registry, engineering, and operating metrics shown on a consistent EIA basis.

Metric	Mammoth Pool Madera County	J S Eastwood Fresno County
Capacity	190 MW	199.8 MW
Technology	Conventional Hydroelectric	Hydroelectric Pumped Storage
Operator	Southern California Edison Co	Southern California Edison Co
Operating units	2	1
Latest 12-month generation	571.5 GWh	203.9 GWh
Latest complete-year capacity factor	28.0% (2025)	—
National technology rank	#73 of 1,349	#27 of 39
Latest EIA report	2026-06	2026-06

Generation comes from EIA-923. Capacity, unit counts, technology, and reporting relationships come from EIA-860. Incomplete reporting years are excluded from capacity-factor comparisons.