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ENERGY AND WATER

Presentation toNREL EnergyAnalysis Forum

Dr. Allan R. Hoffman

U.S. DOE & WinrockInternational

11 June 2003



WATER SECURITY

Water security is the ability toaccess sufficient quantities of clean water to maintainminimal standards of food andgoods production, sanitation

and health



The Water-Energy Nexus

Central to addressing watersecurity issues is having the

energy to extract, transport,manage, treat and desalinatewater resources.

Water and energy issues areinextricably linked.



The Role of Water

Water has always beenmankind’s most precious

resource.

There are no substitutes, and

the struggle to control waterresources has shaped ourpolitical and economic history.



The Role of Water(continued)

Population growth and economicdevelopment are driving a steadily

increasing demand for new cleanwater supplies.

Water is increasingly recognized as

the key environmental issue of the21st century and the key to povertyreduction.



What are the basic facts aboutglobal water supply?

The earth is a water-rich planet, withthe total water supply estimated at

328 million cubic miles. Each cubicmile contains more than one trilliongallons.

Of the 328 million cubic miles, 317million can be found in the oceans(97%)



Basic Supply Facts (continued)

Another 7 million cubic miles is tiedup in icecaps and glaciers, and 3.1

million in the earth’s atmosphere

Ground water, fresh water lakes, andrivers account for just over 2 million

cubic miles of fresh water



Basic Supply Facts (continued)

The net result is that 99.7 percent of all the water on earth is not availablefor human consumption.

Of the remaining 0.3 percent much isinaccessible. The vast majority of water for human and animalconsumption, much less than 1percent of the total supply, is storedin groundwater.



Water and Conflict

Water is not distributed uniformlyaround the globe, and has been a

source of tension wherever waterresources are shared by neighboringpeoples.

Globally, there are more than 250water bodies shared by more thanone country.



SOME INTERESTINGPERSPECTIVES

“The next war in the Middle East will be

over water, not politics.” (Boutros Boutros-Ghali, Secretary General, United Nations)

“The only matter that could take Egypt towar again is water.” (Anwar Sadat,President of Egypt)

“Water is the one issue that could drivenations of the region to war.” (KingHussein, Jordan)

“Many of the wars in this century wereabout oil, but wars of the next centurywill be about water.”(Ismail Serageldin,

Vice President, World Bank)



How Is Water Used Today?

Water use is increasing everywhere.World water demand has more than

tripled over the past half century. On a global basis, approximately

70% of all available fresh water isused for agriculture.

Africa: 88% Europe: 33%

USA: 39%



How Is Water Used Today?(continued)

Over pumping of groundwater by theworld’s farmers exceeds naturalreplenishment by more than 160billion cubic meters per year.

Water shortages now plague almost

every country in North Africa and theMiddle East

Wh t th it ti d



What are the sanitation andhealth impacts of limitedwater supplies?

Over a billion people today lackaccess to clean drinking water in thedeveloping world, and nearly 2.5

billion lack access to adequatesanitation services.

These numbers will grow in the yearsahead.

Water-related diseases are a growinghuman tragedy, killing more than 5million people each year.

S it ti d h lth i t



Sanitation and health impactsof limited water supplies(continued)

Every day, easily prevented diarrhealdiseases cause some 6,000 deaths,mostly children under 5.

Diarrheal diseases have killed morechildren in the past 10 years than allthe people lost to armed conflictsince World War II.

About 60 million children annuallyreach maturity stunted due to severenutrient loss and complications frommultiple diarrheal episodes.



Implications For U.S. StrategicInterests

Shortages of water can lead to conflict in manyparts of the world where water is a transboundaryissue, creating national security problems for theUnited States

Water allocation can be a vehicle to engage regionalparties in constructive dialogue

Sustainable global economic development is majorU.S. foreign policy goal. Water and energy are thecritical elements of sustainable development.

U.S. experience with water resources and theireffective management leads the world. Worldwidemarket in water technologies estimated at $300billion in the next decade.



How is Water Used in the US?

Total fresh and saline withdrawals: 402billion gallons/day

Categories of use:

Irrigation: 39% Thermal power plant cooling: 38%

Residential: 8%

Commercial: 3%

Industrial: 8%

Livestock: 2% Other public use: 2%

(Note: latest available data is in USGS Circular 1200: “EstimatedUse of Water in the United States in 1995”)



U.S. Water Supply Problems

Chemical contamination of surface andgroundwater, as caused by agricultural,industrial and defense related activities

over the past century has been recognizedas an important and widespread problem

Biological contamination of drinking water,often associated with isolated septic tank

or wastewater discharges, has receivedmore attention recently and is now thesubject of important changes proposed forU.S. drinking water regulations.



U.S. Water Supply Problems(continued)

Sea water desalination is beingimplemented in Tampa, Florida aspart of a master plan to provide new

water (10% by 2008) to a regionwhose groundwater resources can nolonger supply the growing urbandemand.

The Ogallala fossil water aquifer inthe Central Plains, with no effectiverecharge, is being depleted by

agricultural and urban extraction.




Reduction of CO River waterallocated to CA, resulting frominability of competing urban,

agricultural and environmentalinterests to agree on a conservationplan to achieve the same reduction.

Increasing number of water disputes

in the eastern part of the U.S. VA vs. MD

VA vs. NC

GA vs. FL vs. AL




Cooling water for thermal (fossil,nuclear) power plants is becoming aserious problem.

The increasing age of much of theU.S. water supply and distributionsystem will require massiverehabilitation investments in thecoming decades (recently estimatedat $800 billion to $1 trillion).



How is the world respondingto the global problem?

A number of voices have sought to soundthe alarm for more than a decade.

World Water Forums (1997,2000,2003)

UN Millennium Summit (2000)

World Summit on Sustainable Development(2002)

International Year of Freshwater 2003

New UN Decade of Water?



Energy Needs of WaterServices

Energy is required to:

• lift water from depth in an aquifer

• pump water in pipes

• treat waste water• desalinate brackish or sea water

Globally, commercial energy consumed fordelivering water is more than 26 quads, 7

percent of total world consumption. A considerable amount of water is also

delivered by utilization of human energy – e.g., use of treadle pumps and watertransport by women and children.

Water Energy Use in



Water-Energy Use inCalifornia:An Interesting Example

Energy demand associated with water usein CA is high for three reasons: most of demand is located at considerable

distance from source

water is heavy and moving it is energy intensive

water used for consumption must be treated,another energy intensive process

Annual water consumption is over 40

million acre-feet (one acre-foot =326,000 gallons)

Energy required annually to pump and treatwater exceeds 15,000 GWh, approximately6.5% of total electricity used in the state

per year



Water-Energy Use by PowerPlants

Cooling water for thermal power plants isthe second largest user of fresh water inthe U.S., second only to water used for

agricultural irrigation

Estimated use is 190 million gallons per day

A 500 MW closed-loop plant requires 7,000gallons per minute (10.1 million gallons perday)



Energy Needed to Lift GroundWater

Power = (water flow rate) x (water density)x (head)

Example: Lift water from a depth of 100 feet at aflow rate of 20 gallons/minute (0.045

cubic feet/sec), assuming an overallpump efficiency of 50%

Power = (2) x (0.045cfs) x (62.4lb/ft3) x (100ft)

= 562 ftlb/sec = 1.0 HP



Energy Needed to TransportWater

Depends on the diameter and length of pipe used

In general, use pipe where water velocity is 3-5 feet/secand water pressure in pipe stays in nominal range

Power = (water flow rate) x (water density)

x (H + HL) H is lift of water from pump to outflow (positive if pumping

uphill and negative if pumping downhill), and

HL is the effective head loss from the water flow in the pipe:• HL = (F) x (L/D) x (V2 /g)

• F = friction coefficient (from table)• L = length of pipe

• D = diameter of pipe

• V = water flow rate

• g = acceleration due to gravity (32.2 ft/sec2)

Energy Needed to Transport



Energy Needed to TransportWater(continued)

Example: Move water uphill 100 feet at 3 feet persecond through a pipeline that is 1 milelong (5,280 feet) and 2 inches (0.167

feet) in diameter (F=0.025). Flow rateis 29.5 gpm (0.066 cfs).

HL = (0.025) x (5,280 ft) x (1/0.167) x (32) x(1/32.2) = 221 ft

Power = (2) x (0.066) x (62.4) x (100 + 221)

= 2,644 ftlb/sec = 4.8 HP



Energy Needed to Treat Water

Most water treatment options require energy levelsof 2-3 feet of head. At a given flow rate, you canuse the first example (slide # 25) to calculate thepower required. This number would cover options

such as simple filtration or ion exchange.

An operation such as ozonization is more dependenton water quality and can require more energy.

Average energy use for water treatment drawn fromSouthern California studies: 652 kWh/AF

Note: in many remote parts of the world, treatmentmust be very basic and inexpensive. This requires adifferent approach to treatment than implied above.



Energy Needed forDesalination

Reverse Osmosis: Pressure (200-600psi) applied to intake water, forcing

water through semi-permeable membrane. Saltmolecules do not pass through membrane. Product

water is potable. On average, energy (electrical) accounts for about

40% of total cost.

5,800-12,000 kWh/AF (4.7-5.7 kWh/m3)*

Distillation: Intake water heated to produce steam. Steam

condensed to produce product water with low saltconcentration.

Energy requirements for distillation (electrical +thermal) are much higher than for reverse osmosis.

28,500-33,000 kWh/AF (23-27 kWh/m3)*

------------------------------------------------------------------* Does not include energy required for pre-treatment, brine disposal and water transport.



Implications for Global EnergySupply

It is now widely recognized that water andsanitation are inextricably linked to theeradication of poverty and the achievement

of sustainable economic development

As a result, the UN has adopted two relatedMillennium Development Goals:

reduce by half, by 2015, the proportion of peoplewithout access to safe drinking water

reduce by half, by 2015, the proportion of peoplewithout access to basic sanitation



Implications (continued)

Today more than 1 billion people lack access to safedrinking water (17%) and nearly 2.5 billion lackaccess to adequate sanitation (41%).

Estimated world population in 2015: 7.2 billion

In order to reach the Millennium DevelopmentGoals:

1.7 billion more people will need to be supplied

access to safe drinking water 2.2 billion more people will need to be supplied

access to basic sanitation

These are large numbers, and the challenge toreach the Millennium Development Goals will be

immense.



Energy System Implications

The kind of energy system chosen to provide waterfor drinking and sanitation will be a function of localcircumstances: What kind of water resources are available, locally and

at a distance (local wells, streams, lakes, aquifers,water that can be piped from a distance)?

What is the quality of those resources, and whattreatment will be required to make the water safe touse(fresh or brackish water, pollution level and natureof pollutants)?

What energy resources are available(grid, diesel,renewable,human)?

What financial resources are available to provide theneeded water infrastructure and related energy needs

What level of training is needed to maintain water andenergy systems?



Concluding Remarks

The problem of global water security isalready serious and is growing moreserious each year

Global water security issues impact U.S.strategic interests

World attention is finally beginning to focuson water security issues

The U.S. is not immune to water securityproblems

Much can be done to address the growingcrisis

It will take time and lots of resources



Concluding Remarks

Considerable effort must be expended toidentify and characterize water resources,and design supply systems appropriate tolocal circumstances

Water issues cannot be separated fromenergy issues

Careful effort must be expended to identifyappropriate energy options needed to meet

water security needs A major analytical effort is needed to

identify the steps needed to meet theMillennium Development Goals

Achievement of these goals will still leavebilli f l i h i

allan hoffman

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