Joint California Energy Commission and California Public Utilities Commission Bulk Storage Workshop November 20, 2015 Kelly Rodgers Energy Program Manager

2 San Diego County Water AuthoritySan 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

Lake Hodges Pumped Storage FacilityLake Hodges Pumped Storage Facility 3 LocationEscondido, CA CommissionedSeptember 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 Capacity Two VFD Units (28,000 HP each) 40 MW Generating 41.4 MW Pumping

4 Growing Need for FlexibilityGrowing Need for Flexibility Source: CAISO Website

5 Output in kWH

6 CAISO Curtailment ForecastCAISO 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 7 Benefits of Pumped StorageBenefits of Pumped Storage Source: CAISO Website