1053 MW Hydro out of service in Fresno, CA — California Independent System Operator
1,053 MW
Nameplate Capacity
3
Generators
units
Hydroelectric Pumped Storage
Technology
1984
Operating Since
Owner data does not fully agree across sources.
EIA typically reports the operating utility, while GEM resolves to the financial owner or parent corporation. Both can be correct.
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | Pacific Gas & Electric Co. | Pacific Gas and Electric | Pacific Gas and Electric Company |
| Owner(s) | Pacific Gas & Electric Co. | PG&E | — |
| Status | Out of service | operating | — |
The Helms Pumped Storage Plant is located 50 miles (80 km) east of Fresno, California, in the Sierra Nevada Mountain Range's Sierra National Forest. It is a power station that uses Helms Creek canyon on the North Fork of the Kings River for off-river water storage and the pumped-storage hydroelectric method to generate electricity. After being planned in the early 1970s, construction on the plant began in June 1977 and commercial operations began on 30 June 1984. It has an installed capacity of 1,212 MW and is owned by Pacific Gas and Electric Company.
Read more on WikipediaHelms Pumped Storage is a 1,053 MW hydroelectric pumped storage plant located in Fresno County, California. The plant, which began operating in 1984, is owned and operated by Pacific Gas & Electric (PG&E). It utilizes water as its primary fuel source and consists of three generators. The plant's installed cost was $902.28 per kW, according to FERC data.
Helms Pumped Storage operates within the California Independent System Operator (CAISO) balancing authority and the Western Electricity Coordinating Council (WECC) NERC region. It is the second-largest of 42 hydroelectric plants in California and ranks as the 18th-largest among 194 pumped storage facilities nationally.
Generated from EIA, GEM, and public data sources
NERC Region
WECC
Balancing Authority
California Independent System Operator
Grid Voltage
230 kV
Regulatory Status
RE
Entity Type
Investor-Owned Utility
Sector
Electric Utility
41.4K MWh
Net Discharge
-425.7K MWh
Annual Net Energy
-4.6%
Capacity Factor
Positive values indicate net discharge (generation exceeds station load). Negative values indicate net charging. Pure battery storage plants are typically net negative due to round-trip efficiency losses.
$1,401/kW
Installed Cost
$85.0/MWh
Operating Cost
PACIFIC GAS AND ELECTRIC COMPANY
Reporting Utility
Cumulative Installed Cost
Per-Unit Cost Trends
Market Position
ISO/RTO Market
CAISO
LMP Node
HELMS1_7_B1
Pricing Hub
TH_ZP26_GEN-APND
Location Type
Pricing Node
Node Source
EIA-860 direct report
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Last updated 2026-03-26
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