Opportunities and Threats of the Water/Energy Nexus

1. Opportunities and Threats of the Water/Energy Nexus Doug Kenney, Ph.D. Director, Western Water Policy Program Getches-Wilkinson Center for Natural Resources, Energy and the Environment University of Colorado Law School Urban Water Institute Palm Springs, CA February 20, 2013

2. The Water/Energy Nexus: General Statistics It takes water to make energy: • In 2005, the nation’s thermoelectric power plants withdrew as much water as farms did, and more than four times as much as all U.S. residents (UCS) • Consumption is much lower (< 5% of withdrawals) • Huge regional variations (due to fuel choices and cooling technologies) It takes energy to manage water: • In California, water management and use consumes 19 percent of the state’s electricity, 30 percent of its natural gas, and 88 billion gallons of diesel fuel every year (CEC). • In Southern California, its not unusual for water management to require 2,000 – 3,000 kWh/acre-foot. (As a reference, ocean desalination is roughly 4,000 kWh/acre-foot.)

3. The W/E Nexus in the News • Shutdowns and brownouts prompted by cooling water levels too hot or too low to safely operate nuclear and coal-fired generators in the Midwest. • Reduced hydroelectric generating capacity in the West. • Deepening civic disputes over shrinking water supplies in Texas between thirsty cities and utilities that wanted to construct new coal-fired plants. • Farmers outbid by “frackers” for surplus M&I supplies in Colorado

4. And it Could Get Worse (the “threat”) • Water for Energy • In 2006, the Energy Information Administration (EIA) predicted water consumption by power plants would double by 2030 • An oil shale boom in western Colorado could require 378,000 acre-feet/year (WRA) • Energy for Water • The Southern Delivery System project (serving Colorado Springs) has an energy intensity equivalent to seawater desalination (WRA) • Water Impacts: Greater Competition, Scarcity, Increased Costs, Environmental Impacts, …

5. Or Better (the “opportunity”) • The energy sector (electricity generation) is changing at an unprecedented rate; some of these changes are water friendly • Since 2005, the ratio of energy generation from coal versus natural gas went from nearly 3:1 to 1:1 • Further manipulation of ongoing changes is possible and perhaps likely given climate change mitigation concerns • These changes could benefit the water sector

6. Water Demands of Electricity Generation

7. UCS EWS Preliminary Findings • Energy and Water in a Warming World (EW3) project of the Union of Concerned Scientists • Focus of current work is impact on electricity generating scenarios on water resources Clemmer, S., J. Rogers, S. Sattler, J. Macknick, and T. Mai. 2013. “Modeling low-carbon US electricity futures to explore impacts on national and regional water use.” Environmental Research Letters (8 015004).

8. 4 Electricity Generating Scenarios (1) Reference Scenario (BAU) • Extrapolates impact of current regulations and expected market forces (2) Carbon Budget • 170 gigatons (presumably sufficient to cap atmospheric CO2 at 450 ppm) (3) Carbon Budget + Nuclear and CCS Coal (4) Carbon Budget + Efficiency & Renewables

9. U.S. Electricity Generation Mix (TWh) (# 1) (# 2) PV Efficiency (#3) (# 4) Utility PV CSP Coal CCS

10. Water Withdrawals (National) Figure 3. National-level water withdrawal results for four electricity scenarios. Scenario 1, reference case; scenario 2, carbon budget, no technology targets; scenario 3, carbon budget with coal with CCS and nuclear targets; scenario 4, carbon budget with efficiency and renewable energy targets.

11. Water Consumption (National) Figure 5. National-level water consumption results for four electricity scenarios. Scenario 1, reference case; scenario 2, carbon budget, no technology targets; scenario 3, carbon budget with coal with CCS and nuclear targets; scenario 4, carbon budget with efficiency and renewable energy targets.

12. Water withdrawal results (in billion gallons per year) for 2030 (blue bars) and 2050 (red bars) by HUC-2 region for electricity Scenarios 1–4; scenario 1, reference case; scenario 2, carbon budget, no technology targets; scenario 3, carbon budget with coal with CCS and nuclear targets; scenario 4, carbon budget with efficiency and renewable energy targets; y-axes have different scales and are for intra-region comparison purposes.

13. Water Withdrawals (Southwestern US)

14. Water Consumption (Southwestern US)

15. Hypothetical Colorado River Water Savings (surface water only) ** DRAFT **

16. Scenarios: (2) (3) (4) (1) ** DRAFT ** Colorado River Basin

17. Challenges (Why Is It So Hard to Do the Right Thing?) • The energy sector may not have strong incentives to pursue “water friendly” strategies in regions where they can outcompete agriculture for water in the marketplace. • Conservation of either resource (water or energy) can be unpopular if benefits are perceived as going to others. • Answer: Legislate it; require it. And do so in the name of reduced social conflicts and cost savings. [Preliminary results suggest the most water-friendly pathways are the least cost.]

18. Summary • The rapid changes in the electricity generating sector will have significant implications for water resources • Those impacts can be positive or negative, and can vary significantly from region to region • Conservation and water-friendly renewables are the obvious tools for taking advantage of the water/energy nexus • In most cases, conservation-based management strategies (for energy and water) are likely to be cost-effective

19. Thank You • For more information, contact me directly: Doug Kenney douglas.kenney@colorado.edu (303) 492-1296 • And please remember that this data is preliminary and should be used cautiously.