Compare power plants

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

Metric	Diablo Canyon San Luis Obispo County	Helms Pumped Storage Fresno County
Capacity	2,323 MW	1,053 MW
Technology	Nuclear	Hydroelectric Pumped Storage
Operator	Pacific Gas & Electric Co.	Pacific Gas & Electric Co.
Operating units	2	3
Latest 12-month generation	18.38 TWh	1.11 TWh
Latest complete-year capacity factor	86.3% (2025)	—
National technology rank	#17 of 54	#8 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	Diablo Canyon San Luis Obispo County	Helms Pumped Storage Fresno County
Capacity	2,323 MW	1,053 MW
Technology	Nuclear	Hydroelectric Pumped Storage
Operator	Pacific Gas & Electric Co.	Pacific Gas & Electric Co.
Operating units	2	3
Latest 12-month generation	18.38 TWh	1.11 TWh
Latest complete-year capacity factor	86.3% (2025)	—
National technology rank	#17 of 54	#8 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.