California Energy Commission

Drought Impacts on Electricity Generation

Joint Workshop on California’s Drought Response

Sylvia Bender, Deputy Director

Energy Assessments Division

August 28, 2015

Sylvia.Bender@energy.ca.gov/916-653-6841

California Energy Commission

Topics to be Covered

• Monitoring and tracking drought impacts from water curtailments and loss of water supplies– Hydroelectric generation– 100 thermal power plants

• On track to reduce water consumption and increase efficiency of thermal plants

California Energy Commission

Hydroelectric Generation Declining as Portion of In-State Generation

California Energy Commission

Thermal Generation and Water Issues

• Thermal power plants require some amount of water, even dry cooled units

• Monitor thermal generation vulnerabilities to water supply shortages during drought

• Tracking 30,000 MW out of California’s 78,000 installed generation capacity – 100 plants> 75 MW– Energy Commission jurisdictional plants (78) and most large natural

gas-fired base load plants

• Surface water curtailments and dropping groundwater levels can impact plants

California Energy Commission

California Energy Commission

California Power Plants Depend on a Diversity of Water Sources

• Among these 100 plants being tracked:– Surface water use spread across 17 water

districts, no one more than 8% of total– Groundwater spread across 13 groundwater

basins• Only 2 thermal plants in a subsidence basin

– Recycled water considered most drought resistant supply

California Energy Commission

Recycled Water Serves the Largest Portion of Tracked Plants

California Energy Commission

Largest Share of Generation Capacity Being Tracked uses Recycled Water

California Energy Commission

Recycled Water is Largest Share of Water Supply at Tracked Plants

California Energy Commission

Thermal Power Plants on Track to Reduce Water Consumption /Increase Efficiency

• Energy Commission 2003 Water Policy

• Increase use of recycled water and dry cooling

– 85% of new 9,000 MW combined cycle projects built since then rely on recycled water or dry cooling

• Thermal efficiency increasing each year over last decade

• Greater use of dry cooled and recycled water plants could achieve additional potable water savings

• Further analysis of water use intensity at power plants underway