Water and Energy Nexus: Strategic Thinking Water + Energy in Changing Climates, 2010 Ground Water Protection Council

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1 Water and Energy Nexus: Strategic Thinking Water + Energy in Changing Climates, 2010 Ground Water Protection Council, Ph.D. Center for International Energy and Environmental Policy The University of Texas at Austin September 29, 2010

2 Water for Energy: Electricity

3 US hydropower exemplifies water limiting an energy resource 0.7 US Hydropower Performance and Capacity Clean Water Act (1972) 120,000 Capacity Factor Capacity Factor Hydro Capacity (MW) 100,000 80,000 60,000 40,000 20,000 Cumulative Net Capacity (MW) EIA Annual Energy Review Groundwater Protection Council 3

4 Cooling systems for Thermoelectric Power Can have vastly different Water Consumption Dry Cooling Wet Cooling Solar CSP and Geothermal (Cooling Towers) DOE (2006). Energy Demands on Water Resources. Report to Congress. Groundwater Protection Council 4

5 Agencies measure water flow at different points EIA Natural evaporation Precipitation Forced evaporation TCEQ Diversion Intake Steam- Electric Plant Cool water Discharge Withdrawal Warm water Cooling Reservoir System Boundary Cooling Towers TCEQ Return Flow TWDB Aquifer Groundwater Protection Council 5

6 Water Consumption depends heavily upon fuel + cooling system and carbon capture choices Texas Water Consumption for Electricity Generation 1,800,000 acre-feet/yr 1,600,000 1,400,000 1,200,000 1,000, , , , ,000 CO 2 cap scenarios Non-CO 2 cap scenarios + 29% + 90% + 69% King, Duncan, & Webber (2008). TWDB Report. Water Demand Projections for Power Generation in Texas Groundwater Protection Council 6

7 Withdrawal vs. Consumption: Which is more important? Use is a bad word for water Withdrawal ~ 48% of US total (USGS, 2004) Consumption ~ 3% of US total (USGS, 1998) Is this a LOT or a LITTLE water for power? The same power plant design can have different water risk on a river on a cooling reservoir with a cooling tower (dry and wet) Groundwater Protection Council 7

8 Steam-based power generation likely must adapt to low water consuming technologies Dry cooling for Solar thermal systems in desert Southwest Prevent Gal/MWh net increases due to auxiliary power and heat for CO2 capture Wind, PV solar, and NG combustion consume very little water directly Legal water rights restrictions may be as influential as physical water availability Groundwater Protection Council 8

9 The scale of 100% renewable energy/electricity overwhelms the water issue US total H 2 O consumption, 1995: 36,500 Bgal/yr (USGS, 1998) ~ 5,400 Bgal/yr in solar CSP resource area (USGS, 1998) 4.1 TW of 25% Capacity Factor (Fthenakis et al., 2009) Wet cooled Billion Gallons H 2 O consumed per year % of Desert Southwest H 2 O 900 gal/mwh 8, % Dry 100 gal/mwh % Groundwater Protection Council 9

10 Water for Energy: Transportation Fuels Dominguez-Faus et al. Environ. Sci. & Technol (9),

11 Water intensity of Light Duty Vehicle travel varies from 0.1 to > 60 gal/mile for consumption King, C. W. and Webber, M. E. Water Intensity of Transportation. Environ. Sci. & Technol (21), Groundwater Protection Council 11

12 One diverse scenario for 2030 imagines ~ 20% conventional petroleum (4.1 trillion miles) Biodiesel - Irr. Soy 0.2% E85 - Non-Irrigated Cellulosic 9.2% E85 - Irrigated Cellulosic 1.7% Biodiesel - No Irr. Soy 3.2% Biomass gasification to liquids 8.6% Gasoline (E10) 20.0% Diesel 3.1% E85 - No Irr. Corn Grain or Stover 9.9% E85 - Irr. Corn Grain or Stover 1.7% Coal to FT Diesel 20.3% Electric (EV/PHEV) - U.S. Grid 8.1% H2 - Electrolysis, U.S. Grid 1.3% H2 - SMR 1.3% Gasoline - Oil Shale 10.4% King, Webber, Duncan (2010) Energy Policy, 38 (2), NG to FT Diesel 0.9% Groundwater Protection Council 12

13 Water consumption could be up to 14,000 GL/yr (3,700 billion gallons) in 2030 (10% of US consumption) 16,000 14,000 12,000 10,000 Water Consumption --- NETL High Diversity Electricity via PHEV US Grid Oil Shale - Gasoline Coal to Liquid (Diesel) Biomass to liquids Irrigated Soy Biodiesel GL/yr 8,000 6,000 4,000 2,000 0 Irrigated Ethanol E85 Corn Grain Irrigated Ethanol E10 Corn Grain Petroleum Gasoline Non-irrigated Ethanol E85 Cellulosic Irrigated Ethanol E85 Cellulosic Non-irrigated Ethanol E85 Corn Grain Irrigated Ethanol E85 Corn Grain & Stover King, Webber, Duncan (2010) Energy Policy, 38 (2), Groundwater Protection Council 13

14 Most intensive irrigation for corn in Western US and Central Plains Chiu, et al. Water embodied in bioethanol in the U.S. Environ. Sci. and Technol (8), Groundwater Protection Council 14

15 Are we trading foreign oil for domestic water? Groundwater Protection Council 15

16 Water and Energy are Becoming More Important in Policy

17 Future water and energy policy: How does water influence energy and GHG? Subtitle D: Energy and Water Integration of American Clean Energy Leadership Act of 2009 (out of committee) include a lifecycle assessment of the quantity of water withdrawn and consumed in the production of transportation fuels i.e. calculate as gal H 2 O/mile King & Webber (2008) Env. Sci. and Tech. To mitigate water resource impact, perhaps the next energy policy act should also insist on a water footprint analysis of all biofuels Keeny (2008) Env. Sci. and Tech. Groundwater Protection Council 17

18 Shale gas/oil fracturing is becoming more mainstream in practice and debate 2005 law exempted shale gas hydraulic fracturing from the federal Safe Drinking Water Act FRAC Act (S. 1215) would reverse exemption and force chemical disclosure 1e-5 gallons of water/btu of Barnett Shale NG (2005) 1 ~ 1% of aquifer withdrawal New EPA study on hydraulic fracturing (target 2012) 1. Bene, J.; Harden, B.; Griffin, S.; Nicot, J. P. Assessment of groundwater use in the Northern Trinity Aquifer due to urban growth and Barnett Shale development.; King and Webber (2008) Env. Sci. & Tech. Groundwater Protection Council 18

19 Groundwater monitoring for CO 2 sequestration/eor impact proves difficult CO 2 feared to mobilize contaminants in groundwater 35 yrs of CO 2 -EOR in Permian Basin Sampling of groundwater shows no conclusive evidence of CO 2 impact to date 1 Test of methodology for CO 2 storage evaluation 2 Simple geochemical parameters are not dependable indicators Diversity of geologic systems and land use practices complicate monitoring protocol 1. Gulf Coast Carbon Center at Bureau of Economic Geology: Smyth, R. 2. Gulf Coast Carbon Center at Bureau of Economic Geology: Romanak, K. and Yang, C. Groundwater Protection Council 19

20 The global view: virtual water trade and climate change mitigation

21 Virtual water trade What about Biofuels? future? Smil, V. American Scientist. Sept-Oct Groundwater Protection Council 21

22 Should US consider ethanol imports to manage domestic water resources? The US was imported literally substituting 72 Billion foreign Gallons oil of direct for domestic water in virtual water. trade What (~8% about H 2 O foreign US ethanol) water? Yacobucci, Brent D. CRS Report RS (2008) Ethanol imports and the Caribbean Basin Initiative. Groundwater Protection Council 22

23 Global energy and GHG models predict wide variability in long term land use change C tax: fossil fuels + land use change Wise, Marshall et al. (2009) Implications of limiting CO2 Concentrations for Land Use and Energy. Science. 324, Groundwater Protection Council 23

24 Global energy and GHG models predict wide variability in long term land use change Another limitation of this study is water, which we have not explicitly modeled. C tax: fossil fuels only Wise, Marshall et al. (2009) Implications of limiting CO2 Concentrations for Land Use and Energy. Science. 324, Groundwater Protection Council 24

25 New data, modeling, and interpretation are needed Carbon vs. Water Carbon (terrestrial storage, biomass potential)? Water (availability and consumption) Groundwater Protection Council 25

26 Thank You WEBBER ENERGY GROUP Center for International Energy and Environmental Policy Ph.D. Center for International Energy and Environmental Policy