Existing Large - Scale Pumped Storage Projects

Joint California Energy Commission and California Public Utilities Commission

Bulk Storage Workshop November 20, 2015

Kelly RodgersEnergy Program Manager

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San Diego County Water Authority Wholesale water agency created

by State Legislature in 1944 24 member agencies 36-member board of directors Serves 3.2 million people and

region’s $218 billion economy Service area

950,000 acres 97% of county’s population

Imports up to 90% of water used in San Diego County

Builds, owns, operates and maintains regional water infrastructure

Largest member agency of Metropolitan Water District of Southern California

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Lake Hodges Pumped Storage Facility

Location Escondido, CA

Commissioned September 2012

Upper Reservoir(Water Authority owned)

Olivenhain Reservoir (24,000 acre-feet)

Lower Reservoir(City of San Diego owned)

Lake Hodges (33,500 acre-feet)

Installed CapacityTwo VFD Units (28,000 HP each)40 MW Generating41.4 MW Pumping

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Growing Need for Flexibility

Source: CAISO Website

Outp

ut in

kW

H

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CAISO Curtailment Forecast

Source: CAISO Website

Can use excess renewable energy during periods of overgeneration

Avoids curtailment and contributes to renewable energy percentage

Non-greenhouse gas energy source can be used later as solar and wind come off line

Highly flexible energy Water-energy nexus – water

rate stabilization

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Benefits of Pumped Storage

Source: CAISO Website