The Water-Energy Nexus in Texas - coloradoriver.org

The Water-Energy Nexus in Texas

Margaret A. Cook

Margaret Cook| Water-energy nexus in Texas 217 November 2016

Surprising Water Facts in the USA

• One-third of all energy consumption is just to boil water at power plants to make steam that drives turbines to make electricity.

Source: Sanders & Webber, 2012



• One-half of all water withdrawals are to cool power plants– We use more water for our

light switches and outlets than our taps, shower heads and toilets



• 13% of all energy is for heating, treating and pumping water– Residential water

heating is 4%– We use more

energy for our water than for our lights

Source: Sanders & Webber, 2012


Dams Make The Largest Power Plants In The World• Three Gorges Dam,

China: 22 GW• Reservoir is almost as

long as Great Britain• Significant impacts

from extra mass– 500+ earthquakes

M>2– 400+ landslides– Tilted the Earth on its

axis, slowing rotation by 0.06 microseconds


Energy and Water• Energy and water are interrelated

–we use energy for water and water for energy• The energy and water relationship is already under strain–constraints in one resource introduce constraints in the other

• Trends imply these strains will be exacerbated–Population growth increases total demand–Economic growth increases per capita demand–Global climate change intensifies the hydrological cycle–Policy shifts towards increasing water-intensity of energy and energy-intensity of water

• Technical and Policy Solutions Exist


There Are Good and Bad Tradeoffs At the Energy-Water Nexus (Quantity)• With sufficiently abundant, clean and affordable

energy, our water problems are solved– Long-haul transfer, desalination, deep wells,…

• With sufficiently abundant, clean, and affordable water, our energy problems are solved– Biofuels, hydro,…

• Coupled infrastructures causes cascading vulnerabilities– Water constraints become energy constraints– Energy constraints become water constraints

7Dr. Michael Webber

Thirst for Power: Energy, Water and Human Survival September 15, 2016


There Are Good and Bad Tradeoffs At the Energy-Water Nexus (Quality)• Energy affects water quality (good and

bad)– Energy is used to treat (clean, move, heat,…)– Energy pollutes water (thermal, chemical,…)

• Water affects energy quality (good and bad)– Improved efficiency at power plants

(thermoelectric, solar PV, …)– Improved recovery for oil and gas production– Degraded performance in heat waves 8

Dr. Michael Webber



Energy Puts Water Quality at Risk

• Coal chemical and slurry spills• Radiation contamination• Mining tails from extractive industries• Thermal pollution

– Hot: thermal power plants– Cold: dams

• Biofuels runoff• Oil spills• Chemical injection

9Dr. Michael Webber



Trends Imply That Strain in the Energy-Water Relationship Will Be Exacerbated


Trends Imply That Strain in the Energy-Water Relationship Will Be Exacerbated• Population growth

– drives up total demand for energy & water• Economic growth

– drives up per capita demand for energy & water– might be counteracted by efficiency

• Climate change: distorted rainfall, snowmelt, etc.

• Policy choices– movement towards energy-intensive water and

water-intensive energy


Growth in Per Capita Demand for Energy and Water Is Driven By Economic Growth• Demand for energy/water growing faster than

population– Growing quickly in developing nations – Level in industrialized nations because of

efficiency gains• Affluent people/societies

– Eat more meat (which leads to water consumption)

– Demand better environmental conditions (which leads to more energy for water treatment)

– Consume more electricity (which uses water)


We Are Moving Towards More Energy-Intensive Water• Stricter water/wastewater treatment

standards• Deep aquifer production• Desalination

– Worldwide capacity to double by 2025– Middle East, London, San Diego, Texas

• Long-haul pipelines and inter-basin transfer– China, India, Texas

• Desalination plus long-haul transfer


We Are Moving Towards More Water-Intensive Energy (Especially For Transportation Fuels)• Biofuels (Up to 1,000

times more water intensive than gasoline)

• Nuclear• Coal with Carbon

Capture


There Are Technical, Social and Policy Solutions


There Are Technical Solutions

• Source Switching– Fuel switching– Water source

switching

• Enhanced Technologies– Water lean

energy technologies

– Energy lean water technologies

– Distributed energy and water technologies

– Smart

Technologies

• Cross-Sectoral Problem Solving– Using the water

sector to solve energy problems

– Using the energy sector to solve water problems


Source Switching Can Save Energy and Water• Water Source Switching: use water sources

that compete less with freshwater– Brackish, saline or reclaimed water for power

plant cooling and oil/gas extraction– Reclaimed or greywater reuse for irrigation or

cooling in homes• Fuel Switching: Use fuels that require less

water– Less water intensive: natural gas, solar PV, wind– More water intensive: nuclear, coal


Cross-Sectoral Integration Holds Promise For Saving Energy and Water• Using the water

sector to solve energy problems

• Using the energy sector to solve water problems


There Are Some Catchy Slogans for Water Solutions• Efficiency:

–“more crop per drop”–“Negawatts” instead of

“Megawatts”• Sanitation differentiates

–Healthy and wealthy = sanitation

–Sick and poor = no sanitation

• Water Re-use:–“showers to flowers”–“toilet to tap”–Graywater for snowmaking


Power plants can use reclaimed water for cooling

• Many thermoelectric power plants use non-fresh water for cooling

• In 2010, 46 U.S. power plants usedreclaimed water for cooling

• Reclaimed water has advantages–Drought-resistant–Can be abundant–Can be safe

• Reclaimed water can pose operational challenges


Opportunities exist for collaboration between WWTPs and power plants• Total existing flow

from WWTPs in Texas: 2.1 billion gal/day

• Total withdrawal for power plants in Texas:28 billion gal/day

• Total consumption for power plants in Texas:0.4 billion gal/day

Courtesy: Ashlynn Stillwell


0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Average PCwater

consumption

Changedue to

efficiency

Changedue tocooling

Change dueto fuel

extraction

Change dueto emissions

controls

AverageNGCC waterconsumption

Wat

er C

onsu

mpt

ion

[gal

/kW

h]Despite Water Needs of Hydraulic Fracturing, Switching From Coal to Natural Gas Combined Cycle Saves Water

Texas Fleet Average Water Consumption per kWhSource: Grubert, Beach and Webber • Graphic: Michael E. Webber, The University of

Texas at Austin© Michael E. Webber


Enhanced Technologies Can Save Energy and Water• Water-lean energy technologies: dry cooling at

power plants, waterless fracking, low-water biofuels

• Energy-lean water technologies: better membranes, using waste heat for water treatment, VFD pumps

• Distributed energy and water technologies: rooftop solar PV, microharvesters for energy, rain harvesters, on-site water treatment for oil and gas producers

• Smart Technologies: better meters and sensors for tracking uses and losses


We Could Make Our Energy and Water Systems Smarter• Conventional meters

are dumb• Need to know:

– Use by time of day– Use by function

• Indoor vs. outdoor• Heated vs. unheated• Greywater vs.

blackwater• Piped vs. collected


The Water Sector Can Be Used To Solve Energy Problems• Energy Recovery from WWTPs• Integrating Renewables with Water

Treatment & Desalination– Abundant saline/brackish water in Texas

• Abundant wind and solar radiation in Texas• 1,000 hours of negative pricing in west Texas

because of abundant wind


The Energy Sector Can Be Used To Solve Water Problems• Integrating Energy, Air Quality & Water For

Dispatching• Incorporating Water Into Grid Planning• Energy Industry’s Needs as a Driver for Water

Efficiency– Towards efficient water markets

• Dry-cooling At Large-Scale Implementation– To Spare Water Rights In TX– As an economical measure for drought resiliency

• Capturing Flared Gases for On-Site Water Treatment


There is Justifiable Cause for a Healthy Dose of Realistic Pessimism That This Could Take a While


There is Justifiable Cause for a Healthy Dose of Realistic Pessimism That This Could Take a While

CAUTION: Reclaimed Wastewater

DO NOT DRINK

Source: Stillwell


So what do we do first while waiting for new technologies?


Start By Eliminating Waste


We Should Improve Energy and Water Literacy With Better STEM Education• Creating an interactive

energy-water course app: Resourcefulness

• Teaches key concepts on energy & water for K-12, industry, gov’t, college and general public

• Working with DISCO Learning Media & Itron, Inc. to make and distribute to school districts


Good news: energy conservation and water conservation go hand-in-hand

• Conserving water will conserve energy

• Conserving energy will conserve water

• Often saves money

Presenter

Presentation Notes

Small scale: Adjust the thermostat Turn off the lights when you leave the room Medium scale: Drive an energy-efficient car Reduce, reuse and recycle Large scale: Make cities more compact and smart Make power plants more efficient


Acknowledgements

• Dr. Michael Webber• Webber Energy Group

• National Science Foundation IGERT• Cynthia and George Mitchell Foundation

www.webberenergygroup.com

Margaret CookGraduate Research AssistantDepartment of Civil, Architectural and Environmental Engineering

[email protected]

The Water-Energy Nexus in Texas - coloradoriver.org

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