Overview of the Energy Water Nexus, Dr. Carey King, University of Texas at Austin

Overview of the Energy Water NexusTexas Alliance of Groundwater Districts

Carey King

Center for International Energy and Environmental PolicyThe University of Texas at Austin

June 26, 2012

Carey King, PhDTAGD 2

June 26, 2012

Water and energy are linked in a fundamental way

• Water treatment and supply require energy

• Water is used in power generation, oil & gas production, and, increasingly, in the production of biofuels

• Conserving water saves energy

• Conserving energy saves water


June 26, 2012

Takeaways

• Marginal energy resource life-cycles often have increased ability to affect or be affected by

– Water quantity– Water quality

• Emotional ties to water affect into energy issues

• Resilience vs. efficiency– Not going to discuss, but think about general goals

of energy and water planning

Water for Electricity


June 26, 2012

US hydropower exemplifies water limiting an energy resource

EIA Annual Energy Review 2008.

Clean Water Act (1972)

0

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1880 1900 1920 1940 1960 1980 2000 2020

Cum

ulati

ve N

et C

apac

ity (M

W)

Capa

city

Fac

tor

US Hydropower Performance and Capacity

Capacity Factor

Hydro Capacity (MW)


June 26, 2012

Determining the factors that lead to this pattern: climate, competing water uses

DOE (2006). Energy Demands on Water Resources. Report to Congress .

Clean Water Act (1972)

US Hydropower


June 26, 2012

Power plant water consumption varies by cooling type

Macknick, et al. (2011). NREL/TP-6A20-50900.

Cooling Towers

1,000 (gal/MWh)

800

600

400Once-

through

Pond

Dry

Hybrid

PV, Wind, CSP Stirling

200


June 26, 2012

Power plant water withdrawal varies by 100X

Macknick, et al. (2011). NREL/TP-6A20-50900.

50,000 (gal/MWh)

Once-through

Pond

40,000

30,000

20,000

10,000Cooling Towers


June 26, 2012

Peak water?Constant US withdrawal for three decades

Hutson et al. (2004). USGS.


June 26, 2012

Withdrawal vs. Consumption:When is each one important?

• Thermoelectric (or energy) “use” of water– Withdrawal ~ 48% of US total (USGS, 2004)

– Consumption ~ 3% of US total (USGS, 1998)

• Avoid using the term “use” to describe water– Can’t tell if “using” a LOT or a LITTLE?

• A power plant withdrawing water from a river/lake versus a dedicated cooling reservoir has different ...

– Operational risks – Environmental impacts


June 26, 2012

Concentrating solar power (CSP):ex. of marginal electricity impacted by water constraint

NREL (2007) DOE/GO-102007-2400.

Direct Normal Solar Radiation kWh/m2/day

8.00-8.257.75-8.007.50-7.757.25-7.507.00-7.256.75-7.006.50-6.756.25-6.506.00-6.255.75-6.005.50-5.752.75-5.50

Wet cooled: @ 800-900 gal/MWh

Dry cooled: @ 100 gal/MWh

+3-5% higher $/MWh


June 26, 2012

Wet Cooling for CSP (trough)

NREL (Kutcher)


June 26, 2012

Dry Cooling for CSP (trough)


June 26, 2012

Coal36.1%

NG46.3%

Nuclear9.1%

Wind6.9%

Other1.6%

Texas generated 437 terawatt-hours in 2011, consuming < 5% Texas water

EIA

For

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Kin

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unca

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nd W

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008)

~0.0 gal/kWh

0.6 gal/kWh

NGCC:0.2-0.3 gal/kWhNG-GT: < 0.1 gal/kWh

0.3-0.6 gal/kWh


June 26, 2012

Texas Water Consumption for Electricity Generation

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ac

re-f

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Texas water planning example:Consumption depends on fuel, cooling, and CO2 choices

CO2 cap scenarios

20% NG

40% NG

King, Duncan, & Webber (2008). TWDB Report. Water Demand Projections for Power Generation in Texas

Non-CO2 cap scenarios

2012 TX State Water Plan

Plant-by-plant estimation


June 26, 2012

Do Texas water rights suspensions during 2011 drought show ‘priority’?

• “Surface water in Texas is owned by the state and held in trust for the citizens of the state.” (TCEQ)

• Texas water rights are (mostly) “first in time, first in right”

– Oldest water rights have senior priority– Water suspensions start with most junior rights

• 2011: “In order to protect public health and welfare, water rights with municipal uses or for power generation have not been suspended.” (TCEQ)

– http://www.tceq.texas.gov/news/releases/010912DroughtLittleSandy– http://www.tceq.texas.gov/news/releases/080811drought11brazos4

Water for Energy: Transportation Fuels

Dominguez-Faus et al. Environ. Sci. & Technol. 2009 43 (9), 3005-3010.


June 26, 2012

Water Consumption Intensity from Near Zero to > 100 gal/mile

King & Webber (2008). Env. Sci. & Tech. 42 (21), 7866-7872.


June 26, 2012

“High Diversity Scenario for 2030”: ~ 20% conventional petroleum (4.1 trillion miles)

Coal to FT Diesel20.3%

NG to FT Diesel0.9%

Gasoline - Oil Shale10.4%

E85 - Non-Irrigated Cellulosic

9.2%

Biodiesel - Irr. Soy0.2%

H2 - SMR1.3%

H2 - Electrolysis, U.S. Grid1.3%

E85 - Irrigated Cellulosic

1.7%

E85 - No Irr. Corn Grain or Stover

9.9%

E85 - Irr. Corn Grain or Stover

1.7%

Diesel3.1%

Gasoline (E10)20.0%

Biomass gasification to liquids8.6%

Biodiesel - No Irr. Soy3.2%

Electric (EV/PHEV) - U.S. Grid

8.1%

Bio

fuel

s

Unconv.

foss

il

Nonliquids

King, Webber, Duncan (2010) Energy Policy, 38 (2), 1157-1167.


June 26, 2012

Will water consumption in 2030 be for fuels non-existent before 2000?

Same thoughts in 1970s energy crisis0

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Water Consumption - AEO 2008 Reference

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Water Consumption - NETL

Irrigated Ethanol – E85 Corn Grain & Stover

Non-irrigated Ethanol – E85 Cellulosic

Irrigated Ethanol – E85 Cellulosic

Non-irrigated Ethanol – E85 Corn Grain

Coal to Liquid (Diesel)

Oil Shale - Gasoline

Electricity via PHEV – US Grid

Irrigated Ethanol – E85 Corn Grain

Petroleum Gasoline

Biomass to liquids

Irrigated Soy Biodiesel

Irrigated Ethanol – E10 Corn Grain

King, Webber, and Duncan (2010) Energy Policy, 38 (2), 1157-1167.Harte and Gasseir (1978) Science, 199, 623-634.

~ 10% US Water Consumption

Water impacts are local but energy trade is global/regional


June 26, 2012

Water resource impacts from energy can be local or remote; quality and quantity

Chiu, et al. Water embodied in bioethanol in the U.S. Environ. Sci. and Technol. 2009 43 (8), 2688-2692.

Hypoxic zone

Aquifer Depletion

Low water availability (oil shale & shale resources)

Shale gas produced water treatment/disposal


June 26, 2012

Hydraulic fracturing in SDWA exemption was integrated water-energy policy

(not necessarily engaged)

• Energy Policy Act (2005) exempted hydraulic fracturing from the federal Safe Drinking Water Act

– Ruling under review– Various ongoing studies (EPA, academic)– Creates animosity public and competing industries

• Issue mostly concerns water quality … not quantity– Millions of gallons per well, many wells per pad

– ~ 1-10 gal H2O/MMBtu of Barnett Shale NG1

• low end of fossil and renewables

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.


June 26, 2012

Policy concerns over CWA 316(b) proposed rule is about withdrawal impacts on wildlife

• 316(b) concerns intake requirements at power plants that might force cooling towers

– New generation units subject to closed loop cooling towers

– Existing plants concerns pushed to states for case-by-case studies

– Minimum fish kill requirement or max. intake velocity


June 26, 2012

Senate Energy and Natural Resources bill seeks to inform and improve data

• Energy and Water Integration Act 2011 (S. 1343)– Calls for National Academies Study of water

energy interactions

e.g. “… include a lifecycle assessment of the quantity of water withdrawn and consumed in the production of transportation fuels …”

– i.e. calculate as gal H2O/mile (King & Webber (2008) Env. Sci. and Tech.)

– Information must be used wisely in policy – What relates to consumers may not to a river basin


June 26, 2012

Not data either!

Texas license plate

http://gaslandthemovie.com/

This is not data on water-energy


June 26, 2012

Much policy discussion centers on US dependence on Middle Eastern/OPEC oil

www.fouralarm.ca

We need to ensure alternative energy resources don’t just switch the pump

Carey [email protected]

http://www.jsg.utexas.edu/cieep

Thank You

http://www.webberenergygroup.com

WEBBER ENERGY GROUP

Center for International Energy and Environmental Policy

Overview of the Energy Water Nexus, Dr. Carey King, University of Texas at Austin

Technology

water planningcarey

peak water

surface water

water resources

water consumption intensity

energy use of water

power plant water consumption

tceq texas water rights