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Helms Pumped Hydro Storage Project

Technology Type Open-loop Pumped Hydro Storage
Rated Power 1212000 kW
Duration at Rated Power (HH:MM) 0:15.00 / 0.00
URL More about Helms Pumped Hydro Storage Project
The power plant operates by moving water between two reservoirs, an upper and a lower. When energy demand is high, water is released from the upper reservoir to the plant where electricity is generated before the water is discharged into the lower reservoir. When demand is low at times such as night, water is then pumped back up to the upper reservoir to be used as stored energy for a later time. This is accomplished by pump-generators which serve a dual role as both pumps which can reverse into generators. The plant can go from a stand still to operational in eight minutes which allows it to meet peak energy demand. It consumes more electricity pumping versus generating electricity but pumping occurs during periods of low demand, making the plant economical. Watch a video about it:
This data has been validated by project staff through a review of publicly available information about the project, and verified by the project owner. Information is accurate as of 2016-04-29.
Project Status
Status Operational
Commissioning On 30.06.1984
Project Includes Multiple Systems No

Fresno County, California
United States

Utility Pacific Gas and Electric
Utility Type Investor Owned
Paired Grid Resource Transmission
Project Includes Multiple Systems No
Ownership & Value Chain Partners
Ownership Model Utility-Owned
Equity Owner 1 Pacific Gas and Electric
Equity Owner 1 Percent 100%
Developer Pacific Gas and Electric
Cost & Performance
Performance Pump/generation cycle efficiency = 72%; breakers average 1,000 operations per year; powers 900,000 homes
Service Use Case Electric Energy Time Shift
Load Following (Tertiary Balancing)
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