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Views on the water intensity of energy supplies Water in a World of 7 Billion. Carey King Center for International Energy and Environmental Policy The University of Texas at Austin May 10, 2012. Takeaways.
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Views on the water intensity of energy suppliesWater in a World of 7 Billion Carey King Center for International Energy and Environmental Policy The University of Texas at Austin May 10, 2012
Takeaways • Marginal energy resource life-cycles have increased ability to affect or be affected by • Water quantity • Water quality • Emotional ties to water clash with mostly economic energy issues • Economic importance of energy can affect water priorities
US hydropower exemplifies water limiting an energy resource Clean Water Act (1972) EIA Annual Energy Review 2008.
Many factors lead to this pattern: policy, climate, competing water uses US Hydropower Clean Water Act (1972) DOE (2006). Energy Demands on Water Resources. Report to Congress .
Power plant water consumption varies by cooling type 1,000 (gal/MWh) Cooling Towers 800 Pond 600 400 Hybrid Once-through 200 Dry PV, Wind, CSP Stirling Macknick, et al. (2011). NREL/TP-6A20-50900.
Power plant water withdrawal varies by 100X 50,000 (gal/MWh) Once-through 40,000 30,000 20,000 Pond 10,000 Cooling Towers Macknick, et al. (2011). NREL/TP-6A20-50900.
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
Wet Cooling for Concentrating Solar Power (trough) NREL (Kutcher, C.)
Dry Cooling for Concentrating Solar Power (trough) NREL (Kutcher, C.)
Regulations on water effluent temperatures can limit power plant generation Data from EPA.
Water for Energy: Transportation Fuels Dominguez-Faus et al. Environ. Sci. & Technol. 200943 (9), 3005-3010.
Water Consumption Intensity from Near Zero to > 100 gal/mile King & Webber (2008). Env. Sci. & Tech. 42 (21), 7866-7872.
“High Diversity Scenario for 2030”: ~ 20% conventional petroleum (4.1 trillion miles) Biofuels Unconv. fossil Nonliquids King, Webber, Duncan (2010) Energy Policy, 38 (2), 1157-1167.
Will water consumption in 2030 be for fuels non-existent before 2000?Similar questions arose in 1970s [2] ~ 10% US Water Consumption Electricity via PHEV – US Grid Oil Shale - Gasoline Coal to Liquid (Diesel) Biomass to liquids Irrigated Soy Biodiesel Non-irrigated Ethanol – E85 Cellulosic Irrigated Ethanol – E85 Cellulosic Irrigated Ethanol – E85 Corn Grain Non-irrigated Ethanol – E85 Corn Grain Irrigated Ethanol – E10 Corn Grain Irrigated Ethanol – E85 Corn Grain & Stover Petroleum Gasoline [graph] King, Webber, and Duncan (2010) Energy Policy, 38 (2), 1157-1167. [2] Harte and Gasseir (1978) Science, 199, 623-634.
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
Data are sometimes not easily converted into information EIA (ft3/s) Natural evaporation Forced evaporation Precipitation now EIA (ft3/s) System Boundary TCEQ (ac-ft) TCEQ (ac-ft) Steam-Electric Plant Cooling Towers Warm water Cool water Diversion Return Flow Cooling Reservoir Intake Withdrawal Discharge TWDB Aquifer
Averyt, K., J. Fisher, A. Huber-Lee, A. Lewis, J. Macknick, N. Madden, J. Rogers, and S. Tellinghuisen. 2011. Freshwater use by U.S. power plants: Electricity’s thirst for a precious resource. A report of the Energy and Water in a Warming World initiative. Cambridge, MA: Union of Concerned Scientists. November.
Energy Price and EROI are inversely related US oil and gas EROI Oil price ($2005/BBL) EROI = Eoutput/Einput King and Hall, “Relating financial and energy return on investment.” Sustainability, 3(10) 2011, 1810-1832; doi:10.3390/su3101810.
Marginal fuels: have lower net energy U.S. Corn Ethanol, soy biodiesel Oil shale Oil sands Brazil cane ethanol (0.4 US$/L) Fuel cost ($2005/BBL) King and Hall (2011), Sustainability. Conventional oil Eoutput / Einput = Energy ROI
Marginal fuels: have higher water consumption (or must recycle) U.S. Corn Ethanol, soy biodiesel 1000 Oil shale 100 Oil sands Brazil cane ethanol (0.4 US$/L) 10 Water Consumption (L H2O/km) (Green and Blue) King & Webber (2008), Env. Sci. & Tech. Conventional oil 1 0.1 Eoutput / Einput = Energy ROI
Marginal fuels: lower net energy & higher water consumption U.S. Corn Ethanol, soy biodiesel 1000 Oil shale 100 Oil sands Brazil cane ethanol (0.4 US$/L) 10 Water Consumption (L H2O/km) (Green and Blue) Fuel cost ($2005/BBL) King and Hall (2011), Sustainability. King & Webber (2008), Env. Sci. & Tech. Conventional oil 1 0.1 Eoutput / Einput = Energy ROI
Is energy ‘special’ when it comes to priority for water access?Example: Texas 2011 Drought
2011 in Texas was driest hottest year on modern record Summer Average Temperature Years of Texas “drought of record” (1950-1957) Summer Total Rainfall John Nielson-Gammon
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) prior appropriation • “first in time, first in right” • 2011/2012: “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
Are there long-term impacts from not suspending power generation water rights? • Is this suspension a market failure? • ERCOT deregulated market ensures equal access to transmission for all participants • Should all power plants have equal access to water? • Water is a strategic asset (brownfield vs. greenfield) • Dry cooling technologies cost more and have higher parasitic losses • Does Texas have a duty to … • Provide water to power plants during drought? • Ensure water rights priority system plays out according to priority date?
http://www.beg.utexas.edu/gccc/ CENTER FOR INTERNATIONAL ENERGY AND ENVIRONMENTAL POLICY WEBBER ENERGY GROUP http://www.webberenergygroup.com http://www.jsg.utexas.edu/cieep Carey King careyking@mail.utexas.edu web: http://www.jsg.utexas.edu/researcher/carey_king/ blog: http://environmentalresearchweb.org/blog/energy-the-nexus-of-everything/