1

D4.4(i):(Output4)AnanalysisofpotentialSTORESenvironmentalandwaterconsumptionimpactsAnnaNadolny,MattStocksandAndrewBlakersAustralianNationalUniversityJune2018

Summary

Our analysis of the water consumption for a renewable electricity system shows that theenvironmentalimpactofSTORESislikelytobeverysmall,bothabsolutelyandrelativetootherpartsoftheelectricityindustry,andatransitionwouldresultinlesswaterbeingconsumedfortheprovisionofelectricity.STORESsitesarenotlikeconventionalhydroelectricity,whereentirerivervalleysaredammed in order to provide seasonal storage – short term storage can be achieved withcomparativelysmalldams,andthereforeverysmallwaterconsumption.Asoursearchforsuitablesitesexcludednationalparksandotherprotectedlands,butstillfound22,000goodsites,onlythemostsuitablefewdozenwouldbeneededtosupporta100%renewableelectricitysystem[1].

WATERCONSUMPTIONINTHEELECTRICITYINDUSTRYElectricity generation in Australia is highly dependent upon water. This report will focus on theNationalElectricityMarket (NEM)andwill outline themultiple inputs forwater foreach formofgeneration,beforedemonstratingthepositivechangethatcouldbeunlockedbymovingtoclean,renewablepower.AsystembuiltonwindandPV,supportedbySTORES,requiresminimalwater.Veryfew,relativelysmallreservoirsareneeded,spreadthroughoutthecountry.Manythousandsofgood off-river sites exist, so sites can be carefully selected tominimise problemswithwater (orenvironmentalmanagement)[1].

Indeterminingthetotalvolumeofwater“used”withintheenergysector,thedifferencebetweenconsumptionandwithdrawalmustbenoted.Totalwaterconsumedwillsometimesbemuch lessthantotalwaterwithdrawn,butthepresenceofsufficientvolumesofwaterintherightconditioncanbecriticalforenergygeneration.Withdrawalreferstowaterthatisremovedfromareservoirwiththeintentionofreturningsomeormostofittotheenvironmentattheendofaprocess.Water“usage”isnotahelpfulterminthiscontext–inthisreportwaterwillbedescribedasconsumedorwithdrawn,exceptwherequotinganotherwork.Table1:Waterconsumptionversuswithdrawal

Consumption Withdrawal

Thermalpowerstationwithcoolingtower

Waterfromcoolingtowersevaporatesintoatmosphere,waterforash&dustsuppression

N/A

Thermalpowerstationwithoncethroughcooling

Somecoolingwaterevaporatesfromreservoir

Mostcoolingwaterisreturnedtoreservoir

Pumpedhydroenergystorage

Initialfillwaterandtopupwatertoreplaceevaporationlossisconsumed,&notavailableforotherprocesses

N/A

2

Hydroelectricity Waterlosttoevaporation Runofriverhydro–waterisdivertedbutreturnedquicklytotheriver

Coal

Coalpowerstationsrequirewaterfortheirconstruction,everydayoperation,andalsoinordertominethecoalitself.

Plantoperation

Waterisrequiredformanyprocesseswithinacoalpower.Thegreatmajorityofthewaterusedonsiteisforcoolingpurposes,forexampleina1000MWcoalfiredpowerstationwith85%capacityfactorandrecirculatedcooling,morethan75%ofwaterconsumptionisduetocooling[2].AlthoughtheAustralianBureauofStatistics(ABS)providesdataonwaterconsumptionfortheentireelectricityandgasindustry–whichrangedfrom288-384GLfrom2008-09to2015-16,mostofwhichprovidedcoolingforcoal,thisinformationisnotprovidedspecificallyforthecoal-firedpowerindustry[3].

Electricitycannotbegeneratedatawater-cooledthermalpowerstation if sufficientwater isnotavailable.Thehighvalueofwatertooperationmeantthatthevalueofwaterforacoal-firedpowerstationin2007was$14-18,000perML,whereasthewholesalecostofwateratthattimewas$1,500perML[2].Wateraccesscanalsoaffectprojectfinancing,duetopotentialrisk[4].

In2009,theWaterlines[2]reportstatedthatmanythermalpowerstationshadalreadyimplementedchangesthatresultedina15%decreaseinwaterconsumptionperMWhofelectricity,duetothehighcostofwater.Furtherlargewatersavingsareonlytechnicallypossiblefornew-buildstations.Thesesystemsusedirect,indirectorhybriddrycooling–butthemajorityofcoalpowerstationsinAustraliauseopen-orclosed-cyclewetcooling[2].

Drycoolingcanresultina90%decreaseinthewaterconsumption,butthesepowerstationsproduceless electricity per unit of fuel consumed, and higher carbon dioxide emissions per unit fuel [2].Alternate sources of water could also lower freshwater consumption within coal-fired powersystems, but eachof thesehaveproblems. Possibilities include: seawater cooling, purifiedwastewater,coalseamgaswater,anddesalination.Thewaterusedwithintheplantmustbepurifiedsothatsaltbuildupdoesnotoccur,particularlyintheboiler–thus,moreelectricityisneededtopurifyanywastewaterusedwithintheplant.Thewatercostandsourceforcoal-firedpowerstationsaredeterminedduringtheplanningstage–changingtooneofthesealternativeswouldprobablymeanhigherassociatedcostsandlowersentoutelectricitygeneration[2].

Thetemperatureofthewaterusedforcoolingimpactsthethermalefficiencyoftheplant–thehighertheintakewatertemperaturethelowerthethermalefficiency[5].Therehavebeenthermalpowerplantsthathaveneededtobeshutdownduetothetemperatureofthecoolingwaterbodybeingtoohigh[6],[7].WatershortagescausedbydroughtinQueenslandin2008meantthat800MWofcoal-firedcapacitycouldnotbeused[8].

Severalcoal-firedpowerstationsusesalineorseawaterforcoolingpurposes,includingGladstone,ValesPoint,andEraring[2].CurrentlydecommissionedplantsintheNEMthatusedseaorsaltwaterincludedMunmorah[2]andWangi[9]inNSW,NorthernandPlayfordBinSA[10].Theseplantsdonotconsumefreshwater,butthewithdrawaldoesaffectabroaderecosystem.Regardless,asthisstudy is investigating freshwaterconsumption, thesalineandseawater fromtheseplantswillberemovedfromthetotalresults.

3

MiningandProcessing

Waterisrequiredincoalmining.In2015-16,coalmininginAustraliaconsumed136GL[11].

Althoughblackcoalcanbeusedwithminimalprocessing,oftenitiswashedinordertoremoveash,rockandminerals– improvingoverallquality.Washingrequires“immersingthecrushedcoal inaliquidofhighspecificgravityinwhichcoalfloatsandcanberecoveredwhiletheheavierrockandmineralssinkandarediscarded”.Theresultantwasteistransferredtoatailingsdam[12],[13].

Gas

Combined-cyclegasturbines(CCGTs)areamongstthemostefficientofthethermalpowerplants,becausehigherthermalefficiencymeanslesswasteheatisgenerated.Asexpected,thislowersthewaterwithdrawalandconsumptionrequirementspermegawatt-hour[14].

NaturalgasproductionintheUSincreasedbyalmost40%between2005and2015.Theboominproductionledtoanincreaseinthenumberofgas-firedplants,someofwhichhavebeenbuiltwithhybrid and dry cooling technologies, and alsowith access to alternativewater supplies, such asreclaimedwater. Coal-fired power plants have been displaced as a result. Overall, in the periodbetween2008and2014therehasbeenadropinthetotalwithdrawalofwater,andalsointhetotalconsumptionintheUS[15].InAustralia,therehasbeennosuchboomingasplantoperation.

ConventionalHydroelectricity

HydroelectricityhashistoricallyprovidedthemajorportionofrenewablesintotheNEM,with7%ofthetotalenergygenerationduring2015-16.ThearidclimateofAustraliawhichrestrictsthenumberandvolumeofrivers,alongwiththeenvironmentaldamagethatcanoccurwhenriversaredammed,has led most people to believe that hydroelectricity cannot contribute much further to thegenerationmix.Thisislikelytrueforconventionalhydroelectricity.

Diverting water from the natural flows of river systems has led to environmental problems.Competition within the Murray Darling Basin has led to tension between environmentalists,irrigators,andpowergenerators.

Theselargewaterbodiesalsoleadtowaterlossfromevaporation.ThisneedstobeaccountedforinaridAustraliaandismanagedinthedesignandoperationstages.TheSnowyHydrooperatorshavehistoricallykeptwaterlevelsatjust10%fortheTantangaraDam,becausetheaboveaveragewindinthe area means evaporation is high for this shallow water body. Changes to the water systemmanagementnowmeanthatthedamwillnowbekeptat20%[16].

EvaporationandRainfallforHydroelectricityandPHES

Pan-evaporationismeasuredusingametalcylindricalpanwithadiameterof1.2metres.Therateofevaporationisdependentuponmanyfactors.Thesmalldiameter,coupledwiththeexposedmetalsides,meanthatedgeeffectsincreasetheevaporationfromoneofthesecontainerswhencomparedto the evaporation from a largerwater body. This difference is commonly reported as 30% lessevaporationinthereal-worldcase[17],[18].

Thepurityofthewateralsoimpactsevaporation.Thesaltinsalinewaterlowersevaporationrates[17].Evaporationwillvarybytheyear,andbythemanagementofthewatersystem.

Local conditions, includingwind and incident solar, also affect evaporation. If a lakeor lagoon issurroundedbywoodedhills,evaporationwilllikelybelowerthanonesurroundedbyflatpastureland.The value for pan evaporation for different locations within Australia can be seen in Figure 1.Australia’s major hydroelectric plants are located in Tasmania and the Alpine region near theNSW/Vic border –where evaporation rates are quite low.Given the dependence upon location,

4

ratherthanusingagenericvaluefromtheliterature,evaporationfromthesespecificsystemshasbeencalculated.

TasmaniahasrelativelylowevaporationandhighrainfallwhencomparedwiththerestofAustralia,andso therearemanynaturalandmanmadewaterbodies thatareused topowerhydroelectricplants.ThewaterbodiesintheSnowyHydroschemearemuchsmallerthanthoseinTasmania.

Evaporationsuppressionisgenerallynotappropriateforconventionalhydroelectricdams.Mostofthesehavemixeduses, including swimming,boating, fishing, irrigation,environmental flows,andurbanwatersupply.Typicalsuppressiontechniquesmeanthatthepubliccannotusethewater,andsomecanresultinchemicalsleachingintothewater.Therearesometrialsoffloatingsolarcollectorsforevaporationreductionandcooleroperation.

Figure1:Averageannualpanevaporation(largerimagecanbeseeninAppendix)[19]

Pumpedhydroenergystorage

WaterforSTORESisconsumed,becauseoncethiswaterhasenteredtheclosedsystem,(ideally)itwillnotbereturnedtotheenvironment.Unlikemanyfossil-fuelsystems,STORESrequiremostofthewaterconsumptionup-front,beforetheplantcanoperate,butthenrequiresonlysmallvolumesofwaterinordertokeepthesystemrunning.Thesesmalltopupsmaynotbenecessary,dependinguponthelocalrainfallandrunoff,andwhetherevaporationinhibitorsareused.Inordertomodelthisinitialwatervolume,thetotalwasdividedbythe50-yearlifetimeofthefacility.

Evaporationsuppression

Therearemanydifferenttypesofevaporationsuppressors.Mosttechniquesworkbyeliminatingairmovementnear thewater surface,whichblowsawayahumidboundary layer leading to furtherevaporation. These range from simple floating plastic containers, to chemical monolayers.Windbreakscanalsobehelpfulinloweringevaporation.Thesimplestwaytolimitevaporationinanewwaterbody is todesign itsothat it isdeepandnarrowsoastoreducewindspeedsonthereservoir–butthisisnotalwayspossible.Treescanreduceevaporationbyupto20%–butiftheyareplantedtooclosetothereservoir,theymayusethewaterthemselves.

5

Chemicalmonolayersareoneof thesimplest formsofevaporationsuppression.Thesechemicalsformalayerontopofthewaterandreduceevaporationbyupto40%.Unfortunately,theyarenotalong-termoption,asthemonolayeritselfisbrokendownbybacteria.Theyarealsostronglyaffectedbytheweather.Windandwaveswilleasilydisturbamonolayer[20].

Suspendedshadestructurescanprovideupto75%reductioninevaporation.Structurescanbeusedwhetherthewaterbodyisfullorempty.Installationcanbedifficultifthesurroundingsoilisoflowquality.Thesestructurescanalsobedamagedinhighwinds[20].

FloatingCovers: There aremanydifferent floating cover products on themarket.Manufacturersclaimevaporationreductionratesofcloseto100%–butrarelyprovideinformationonindependenttrials.Completelyclosedcoverswouldentirelyremoveevaporation,butalsostoprainwaterfromenteringthecatchment.Ifthereservoirisatriskofdryingout,thefloatingcovermustberemovedas it could become bogged down. Depending upon the material used, algal bloom can also beeliminated.Theeffectofhighwindisalsoproductdependent[20].

Evaporationsuppressioncanbeachievedthroughplasticballs.DarkplasticismoreresistancetoUVlight,whichincreasestheusefullifetimeoftheproduct,althoughresultsingreatersolarheatingofthewater.Theseballsneedtocontainballastmaterialtopreventtheballsfrombeingblownawayinthewindandbecominglitter.Coveringareservoirwithplasticballsblocksoutalllightwhichmeansalgaecannotgrow,andbirdsandanimalsareunlikelytodrinkfromthereservoir.Plasticballswereused in California on several reservoirs in order to prevent bromate from forming due to theinteractionofsunlightwithbromideandchlorine[21]–[23].

PlasticballsareproducedfromHDPE.AlthoughusingblackHDPEratherthanlightercoloursincreasesthelifetimeoftheproduct,allplasticsareexpectedtoeventuallybreakdown.Stillasthewaterinapumpedhydro system is cycled, and is not released to theenvironment, this degradation is lessproblematical.Periodicreplacementoftheballsisindicated[24],[25].

FloatingsolarPVpanelscouldbeusedforconventionalhydroelectricdams.Particularlyonthelargestdams,thesewouldprovideevaporationsuppressionbyinterruptingtheflowofwind,andthedamcouldprovideagoodlocationforsolargeneration.Awell-placedarraywouldhavenoshading,andloweroperationaltemperaturesduetothewater.Landwouldnotneedtoberepurposedforthissolararray.LismoreCouncilandGoulburnCouncilhavebothinstalledfloatingsolararraysonwaterbodies.However,thesewereondrinkingwaterandwastewaterreservoirs,ratherthanreservoirsthat areavailable forpublicuse. For STORES systems, the largedaily and seasonal cyclingof thereservoirs(fromnearlyemptytofull)meansthatfloatingPVmightbeimpractical.

Bioenergy

Bioenergycurrentlyprovides2%ofthegenerationwithintheNEM.Thefeedstocksusedin2015-16included bagasse, wood andwoodwaste,municipal and industrial biomass waste, sulphyte lyer(blackliquor)andbiofuels,landfillbiogasandsludgebiogas.Bagasseandlandfillbiogaswereusedtoproduce75%ofthetotalenergyfrombiomass.Apartfromwood,eachofthesebiomassproductsarewasteproducts,andsothewaterassociatedwithgrowingcropsandcollectingthemdoesnotneedtobeincludedintheelectricitygenerationwaterfootprint.Theoperationalwaterconsumptionisgenerallysimilartoanythermalpowerplant.Therearesomebioenergyplantsthatburnfuelinopencyclegasturbinestoproduceelectricitydirectly,withnosteamrequired.

It is likely that thebioenergymarketwill continue togrowslowly.Bagassewaste isbynomeansexhausted,andlandfillbiogasisparticularlycostcompetitive[26].

6

Large-ScalePhotovoltaics

Although many companies now offer photovoltaic cleaning services, or even the installation ofautomaticcleaningsystems[27],companiesoperatingwithinAustraliahavediscoveredthatthereisnoneedtowashmodules,andthatenergylossesfromdirthavebeenintherangeof1%,dependinguponlocation.

Small-scalephotovoltaics

Awelldesignedresidentialsolarsystemshouldbeinstalledsothatnormalrainfallwillkeeppanelsrelativelycleanoverthecourseoftheyear. Ideally,therewon’tbeanyoverhangingobjectsuponwhich birds can perch and so increase the need for cleaning. Water consumption for cleaningresidentialandbusinesssolarpanelsisdifficulttoascertain,andratherthanbeingcountedwithinthetotalindustrialwaterusedforelectricityandgas,astheABSdoesnow,thiswouldbeincludedwithinurbanwaterconsumption.

Wind

Wind turbines do benefit fromwashing as a part of routinemaintenance. This does not requiresignificantvolumesofwater.

WaterforGenerationTechnologies

TheAustralianBureauofStatisticsprovidesabreakdownofelectricitygenerationbysourcefrom2008-09onwards.Thesevalueswereusedtomodelwateruseinthebaselineelectricitysystem.

InordertomodelarenewableenergyscenariofortheNationalElectricityMarket,hourlyhistoricaldemanddatawascombinedwithhistoricalwindandsolardatatofindthelowestcostgenerationmix that fulfilled theNEMstability requirement.Theoriginalmodelprovided information for theperiod2005-10,butastheABSprovidesinformationfrom2008-09onwards,onlytwoyearsoftherenewablescenariohavebeen includedbelow[28].Thissystemmadeuseof legacyconventionalhydroelectricandbioenergyplants–however,althoughthismodelassignedbioenergytoprovide887and1147GWhfor2008-09and2009-10respectively,itislikelythatownersofbiomassplantswillexhausttheirsupplyeachyearratherthansavefeedstocksforthefuture.Moreinformationonthismodelcanbefoundatthisreference:[29].

Valuesforthewaterfootprint(WF)ofthesetechnologies,thatis,thevolumeofwaterrequiredperunitofenergy,werefoundintheliterature.ThesevaluescanbefoundinTable2below.Thefollowingsectiondescribes themethodused tocalculate thewaterconsumption foreach technology.ThewaterfootprintforsomeofthesetechnologieshasbeencalculatedfortheAustraliancontext.

Coal

Thewaterfootprintfortheoperationofcoal-firedplantswastakenfromTable2.Asdiscussedabove,someblackcoal-firedpowerstationsuseeithersalineorseawaterforcoolingpurposes.Asthisstudyisinvestigatingfreshwater,butoperationaldataaren’tavailablefortheindividualplants,thetotalenergyoutputwasloweredbyascalingfactorof24%,accordingtothecapacityoftheplantsthatusesaltwateranddrytechnologyforcooling.Theseplantsdousefreshwaterforotherpurposes.Drycoolingisusedfor12%ofcoalcapacityintheNEM,andsaltwaterfor18%ofcapacity.

Coalasfuelisalsorequired.Asdiscussedabove,thisfuelhasanadditionalwaterfootprint.ThefuelfactorfromTable2wasusedtodeterminethiswaterconsumption.

7

Gas

Waterconsumptionforopencyclegasturbines(OGCTs)andCCGTsistakenfromTable2.OCGTdoesnotrequirecoolingwater.Gasalsohasafactorinthefuelsupplyline,takenfromthesameTable.

ConventionalHydroelectricity

TheABSdonotdefinewateruse in conventional hydroelectricity as “consumption”because thewaterisreturnedtotheenvironment[3].However,creatinghugereservoirsresultsinwaterlosstoevaporation.Thesereservoirsareoftenusedformanyotherpurposes,someofwhichwouldnotbeavailablehadthesystemsnotbeenconstructed.Theseuses includeenvironmental flows, fishing,water sports, the associated services to tourists, water storages for irrigation, and urban watersupplies.Ratherthanapportionthewaterlosstoevaporationtoeachoftheseuses,wepresentthefulllossinthetablebelow.

Evaporationwillvarybytheyear,andbythemanagementof thewatersystem.PanevaporationlevelsacrossAustraliacanbeseeninFigure1.Asdiscussedabove,ascalingfactorof70%wasusedtoconvertthepanevaporationtoreal-worldlevels.

HydroelectricplantsinAustraliaaremostlylocatedwithintheSnowyHydrosystemsinNSW,VictoriaandTasmania.Theseareasarecharacterisedbylowerthanthenationalaverageevaporation.

SnowyHydropublishesinformationdetailingtheheightandthetotalcapacityofthedamswithinthesystem. This information is shown in Table 5 in the Appendix. Information about the long-termaverage levelofLakeEucumbene,which iscurrently59%ofgrosscapacity,andthe levelofLakeTantangara,whichwillnowbeheldat20%,isalsoprovided[16].Thesedatadonotallowtheareaofthedamstobecalculated,particularlygiventheirregularshapeofmanyofthedams.

GoogleEarthprovidessomehistoricalimagery.Unfortunately,theperiod2008-09and2009-10usedin thismodel isnot included in theavailable imageryofmanywaterbodies in the scheme– theavailableinformationistabulatedbelow,inTable6andTable7.Thisinformationisimportantforthismodel,becausetheevaporationdependsuponthesurfaceareaofthewaterbody,buttheplantoperatorsaregenerallymoreconcernedwiththelakelevelpresentedasapercentage.AlthoughtheofficialsurfaceareaofLakeEucumbeneis14,542hectares,theApril2011historicalimageshowsthelakewascloserto7,300hectares.

TasmanianHydroprovidesinformationonlakelevels,butmanyofthewaterbodiesinthissystemareverysmall,andofficialdataisnotpubliclyavailable.GoogleEarthwasusedtofindthesurfaceareaofthesedams.

Oncethetotalsurfaceareaofthewaterbodieswasdetermined,evaporationwasfoundineachareabyapplyingtherelevantpanevaporationvalue.Giventhelackofhistoricalinformation,asinglefigurewasdeterminedforevaporationforbothyears.Thisfigurewas14,901m3/TJ,whichiscomparabletothevaluefromtheliteratureof15,100m3/TJ,foundinTable2.

PHES

TherequiredPHESpowerdemandof16GWand31hoursofcapacitywastakenfromtherenewablemodel.ThesefigureswereenteredintoasimplifiedPHEScalculatortofindtheappropriatereservoirsurfacearea,whichrequiredvaluesforthehead(thealtitudinaldifferencebetweentopandbottomreservoir),andtheaveragereservoirdepth.Thesevalueswere:head400m,averagereservoirdepth40m,areaofcombinedreservoirs3,350ha.

22,000potentialupperreservoirshavebeenmappedthroughoutAustralia,whichareinsomeareasmorethan1000timesthePHESinstallationsthatwouldberequiredtoprovidebalancingservicestoarenewableelectricitygrid.Fewsiteswouldbeneeded,whichmeansthatonlythebestneedbe

8

considered. A good installation will have large head, and low construction costs (these aredeterminedbythemorphologyofthesite).Higherdamwallsaretypicallymoreexpensive,butresultindamswithlesssurfaceareaperunitvolume,andhencelessevaporation.

ThetotalwatercapacityofthePHESsystemmustbesourcedbeforetheplantcanoperate.Thiswaterconsumptionwaslevelisedoverthe50-yearlifetimeofthesystem.

PHES plants are generally most appropriately sited when they are close to distributed powergeneration,andclosetomajortransmissionlines.SitesthatmatchwiththerequirementofalargealtitudinaldifferencearefoundalongtheGreatDividingRange.ThepanevaporationvalueforthisregionwasusedtodeterminePHESevaporation,alongwiththecorrectionfactor.

Evaporationsuppressionwasalsoincludedinthismodel.Formoreinformationonthesuppressionmethods,pleaseseebelow.Thefollowingchartshowstheannualtheoreticalevaporationandtheyearlycomponentoftheinitialfill,fortheentirePHESfleet.

Figure2:Evaporationanddistributedinitialfillperyearfordifferentlevelsofevaporationsuppression

Evaporationsuppressionisrarelyperfect,andsoonlylevelsupto90%havebeenmodelled.

Bioenergy

ThegreatmajorityoffeedstockusedforbioenergyinAustraliacomesfromwastematerial,suchascanesugarwaste,landfillgas,orsewagegas.Assuch,thereisnoadditionalwaterconsumptionforthefuel.BioenergyplantsinAustraliaeitherusesteamturbines,orsimplyusethegaseousfuelinagasturbine.

Photovoltaics

ABSdatawereused todetermine theenergygenerated fromPV in thebaselinemodel, and therenewable scenario generation was taken from [29]. As mentioned in the section above, somecommercialsolar farms inAustraliadonotwashtheirpanels,asoverall lossesarenotenoughtowarranttheexpense.WatertowashresidentialPVisdifficulttoascertain–someownerssetandforget,whereasothersmaywashcarefullyonaschedule.Thisconsumptionwouldbeattributedtourbanwateruse.Regardless, thewaterconsumption forbothsmall-and large-scalePVhasbeenincludedinthisstudy–calculatedusingtheoperationalfactorinTable2.Thesevaluesarethemedianvaluestakenfromdataencompassingmanydifferentstudies,andwhichhadverylargeranges.Given

0

10,000,000

20,000,000

30,000,000

40,000,000

50,000,000

60,000,000

0 10 20 30 40 50 60 70 80 90 100

m3p.a.

%

InitialfillEvaporation

9

that themajority of solar globally is installed in East Asia and Europe [30],which have differenthydrological and pollution conditions than Australia, this result will be higher than that of anAustraliansolarfarmwaterconsumption.ThewaterforPVremainsmuchlowerthanthatforanyfossilfuel.

Wind

Windturbinemaintenanceincludeswashing–theoperationalfactorinTable2wasusedtocalculatethetotalconsumption.Table2:Consumptivewaterfootprint(m3perTJ)forelectricityandheatgeneration,overtheperiod2008-12[31],[34]

Firewoo

d

Hydropo

wer

Nuclear

Oil

Coaland

lignite

Geo

thermal

Naturalgas

Solar

Wind

Operation 400 15,100 610 440 440 340 240 50 0.2

Construction 0.4 0.3 0.3 1.1 1.1 2.1 1.1 90 1.1

FuelSupply 156,000 0 68 55 54 0 6 0 0

Table3:Currentfossil-centricsystemandassociatedwaterconsumption[28]

2008-09 2009-10 2008-09 2009-10

GWh GWh m3water m3water

Non-renewablefuels

Blackcoal 118,533 114,112

165,736,883 143,600,744Browncoal 56,981 56,068 101,335,722 99,711,865Naturalgas 21,231 26,447 18,802,085 23,421,109Oilproducts 884 615 1,575,644 1,096,286Othera 1,427 1,971

Totalnon-renewable 199,056 199,213

287,450,334

267,830,004

Renewablefuels Bagasse,woodb 1,763 1,762 2,539,296 2,536,992Biogasb 903 885 1,300,320 1,274,688Wind 3,149 4,388 2,267 3,159Hydro 11,869 13,549 720,267,800 720,267,800Large-scalesolarPV - - - -Small-scalesolarPV 136 363 24,552 65,340Geothermal 1 1 612 612

Totalrenewable 17,821 20,947

724,134,847

724,148,591

Total 216,877 220,160 1,011,585,181 991,978,595

Table4:Possiblerenewablesystemandassociatedwaterconsumption[29]

2008-09 2009-10 2008-09 2009-10

10

GWh GWh m3water m3water

Renewablefuels Bioenergy 887 1,147 1,277,226 1,651,483Wind 170,995 165,468 123,116 119,137Hydro 17,891 20,348 720,267,800 720,267,800Large-scalesolarPV 12,525 12,586 2,254,469 2,265,486Small-scalesolarPV 22,805 23,139 4,104,840 4,165,059Pumpedhydro 16,537 16,200 55,599,041 55,599,041

Total 241,639 238,888 783,626,491 784,068,006Totalexcl.legacy 222,862 217,393 62,081,466 62,148,723Totalexcl.leg&incl.EvapSup 24,099,952 24,167,210

ThesefigurescanbecomparedwithcommercialwaterextractionfromtheMurrayDarlingBasintodemonstratethescaleofthechange.Thenominallysustainableextractionlevelofthelatteris11,000GLperyear[32],whereastheelectricitysystemcurrentsystemconsumes1,001GLperyear.Therenewableoptionconsumes784GLperyear,mostofwhichisevaporationfromtheexistinghydroreservoirs.AnAustralianelectricitysystemderiving90%ofitsannualenergyfromPVandwindwithPHESsupportconsumes62GLperyear(excludingexistinghydroandbio).Including90%efficientevaporationsuppressiononthePHESfurther lowersthisto24GLperyear.This is just2%ofthestatusquo.

OTHERENVIRONMENTALIMPACTSOFSTORESEnvironmentalimpactsofSTORESincludewaterconsumption,alienationoflandusedforreservoirs,andthedisturbancesassociatedwithpressurepipelines,feedwaterpipelines,roads,powerstations,switchyards and powerlines. The environmental impacts of STORES excluding water impacts isdiscussedinthissection.ItisnotpossibletobespecificsincethelocationofSTORESsystemsisnotpresentlyknown.However,ageneralanalysisispresented.

TheconclusionofouranalysisisthattheenvironmentalimpactofSTORESislikelytobeverysmall,bothabsolutelyandrelativetootherpartsoftheelectricityindustry.Twoimportantpointsinformthisconclusion:

• Wehaveexcludednationalparksandotherlandontheprotectedlandsdatabase(CAPAD)fromoursitesearching

• We found 22,000 good sites, but only a few dozenwould ever need to be developed tosupporta100%renewableelectricitysystem.Thismeansthatsiteswithsmallenvironmentalimpactcanbeselected,thusbypassingsiteswithlargerpotentialenvironmentalimpact

Landuse:Theamountofenergystoragerequiredtosupporta100%renewableelectricitysystemisabout450GWh[8].Thiscorrespondstoarequiredareaofreservoirofabout3600Ha(calculatedthroughthewell-knownequationsforenergystoragepotential).Thisisatinyfraction(5partspermillion)ofAustralia’slandmass(769,000,000Ha).

ArenewableAustralianelectricitysystembasedon30%windenergy,30%ground-mountedsingleaxistrackingPV,30%roof-mountedPVand10%existinghydroandbiorequiresabout22GWofwindturbinesand39GWofsingleaxistrackingPVsystems(assumingaveragecapacityfactors20%and

11

35% for ground-mounted single-axis-tracking PV andwind respectively). Land alienated by thesesystemsisestimatedasfollows:

• Wind:22GWcomprising4,400turbineswitharatingof5MWeach.Eachturbinedirectlyalienatesa500m2blockofland,plusa4mwide,1000mlongaccessroad,givingatotalof2,000Ha

• Groundmounted PV: 39 GW of 20% efficient panels requires 1 Ha per 2MW of panel.Allowingspacingof3:1betweenthepanelsmeansthattherequiredlandareaofabout1.5HaperMW,or59,000Haper39GWalthoughthislandcouldhavesecondaryagriculturalusesuchassheepgrazingbetweenthepanels.

• Roof-mountedPV:noadditionallandisalienated• STORESpumpedhydro:3,600Ha

Thus,totallandalienationofa90%PV/wind/PHESelectricitysystemisabout65,000Ha,90%ofwhichisassociatedwiththePVsystems.ThisisatinyfractionofAustralia’slandsurfacearea(lessthanonepartin10,000).TheareaofhydroelectricreservoirsintheSnowyMountainsandTasmaniansystemsis134,000Ha,whichisaboutdoublethisarea.

Other impacts:Apart from landalienationandwateruse, thepotentialenvironmental impactsofPHESsystemsincludesvisualintrusion,weedandferalanimalinvasionalonginfrastructureroutes,erosion,fragmentationofecosystems,smallalterationstowaterflowonminorstreamsanddrainagebasins, and small noise generation from turbine/pump operation and vehicle access. Standardenvironmentalandengineeringcontrolscanbeusedtominimisetheseimpacts.

Acknowledgements: the contributions of many people to this work is gratefully acknowledged,particularlyMarkDiesendorfwhoprovidedvaluablecommentsonthefinaltext.Responsibilityfortheworkistakenbytheauthors.

References

[1] A.Blakers,M.Stocks,B.Lu,K.Anderson,andA.Nadolny,“Anatlasofpumpedhydroenergystorage,”2017.[Online].Available:https://www.dropbox.com/s/5s5cbwcw32ge18p/170919PHESAtlas.pdf?dl=0.

[2] A.SmartandA.Aspinall,WaterandtheelectricitygenerationindustryImplicationsofuse,no.August.Canberra:NationalWaterCommission,2009.

[3] AustralianBureauofStatistics,“4610.0-WaterAccount,Australia,2004-05,”28-Nov-2006.[Online]. Available:http://www.abs.gov.au/AUSSTATS/abs@.nsf/allprimarymainfeatures/6F380840F971B08DCA2577E700158A5E?opendocument.

[4] AustralianGovernmentDepartmentofResourcesEnergyandTourism,EnergyWhitePaper2012:Australia’senergytransformation.Canberra,2012.

[5] World Nuclear Association, “Cooling Power Plants,” Feb-2017. [Online]. Available:http://www.world-nuclear.org/information-library/current-and-future-generation/cooling-power-plants.aspx.

[6] D.Murrant,A.Quinn,L.Chapman,andC.Heaton,“WateruseoftheUKthermalelectricitygenerationfleetby2050:Part2quantifyingtheproblem,”EnergyPolicy,vol.108,no.April,

12

pp.859–874,2017.

[7] The Guardian, “Heatwave hits French power production,” The Guardian, 13-Aug-2003.[Online].Available:https://www.theguardian.com/world/2003/aug/12/france.nuclear.

[8] NSWChiefScientist&Engineer,“FinalreportfromtheEnergySecurityTaskforce,”19-Dec-2017. [Online]. Available:http://www.chiefscientist.nsw.gov.au/__data/assets/pdf_file/0019/136711/171219-MASTER-NSW-Energy-Security-Taskforce-report-FINAL-SIGNED.pdf.

[9] K. I. M. Robinson, “Effects of thermal power station effluent on the seagrass benthiccommunitiesofLakeMacquarie,aNewSouthWalescoastallagoon,”Wetl.,vol.7,no.1,1987.

[10] Flinders Power Partnership, “Environmental Closure and Post Closure Plan Augusta PowerStations,” Oct-2016. [Online]. Available:www.epa.sa.gov.au/files/12425_station_closure_plan_18_oct_2016.pdf.

[11] AustralianBureauofStatistics,“4610.0-WaterAccount,Australia,2015-16,”23-Nov-2017.[Online]. Available: http://www.abs.gov.au/AUSSTATS/abs@.nsf/Latestproducts/4610.0MainFeatures22015-16?opendocument&tabname=Summary&prodno=4610.0&issue=2015-16&num=&view=.

[12] CommonwealthofAustralia,“CoalFactSheet,”AustralianAtlasofMineralsResources,Mines& Processing Centres, 2015. [Online]. Available:http://www.australianminesatlas.gov.au/education/fact_sheets/coal.html.

[13] A. Kumar, “Coal Preparation,” InfoMine, Jun-2015. [Online]. Available:http://technology.infomine.com/reviews/coalpreparation/welcome.asp?view=full.

[14] International Energy Agency, “Water for Energy: Is energy becoming a thirstier resource?Excerpt from the World Energy Outlook 2012,” 2012. [Online]. Available:http://www.worldenergyoutlook.org/media/weowebsite/2012/WEO_2012_Water_Excerpt.pdf.

[15] R.A.M.PeerandK.T.Sanders,“ThewaterconsequencesofatransitioningUSpowersector,”Appl.Energy,vol.210,no.August2017,pp.613–622,2018.

[16] Snowy Hydro, “Water report 2012-13,” 2013. [Online]. Available:http://www.snowyhydro.com.au/wp-content/uploads/2016/10/SHL_WaterReport_2012-13.pdf.

[17] E. Linacre, “Ratio of lake to pan evaporation rates.” [Online]. Available: http://www-das.uwyo.edu/~geerts/cwx/notes/chap04/eoep.html.

[18] M.E.Jensen,“Estimatingevaporationfromwatersurfaces,”inCSU/ARSEvapotranspirationWorkshop,2010.

[19] Australian Government Bureau of Meteorology, “Average annual, seasonal and monthlyevaporation,” 2006. [Online]. Available:http://www.bom.gov.au/jsp/ncc/climate_averages/evaporation/index.jsp.

[20] Sheep Connect SA, “Controlling Dam Evaporation,” 2017. [Online]. Available:https://www.sheepconnectsa.com.au/water-security/water-sources/controlling-dam-evaporation.

[21] Euro-matic, “Floating cover balls.” [Online]. Available: http://euro-matic.eu/en/products/floating-cover-balls/.

[22] AdvancedWaterTreatmentTechnologies,“ArmorBall(R):HollowPlasticBallCover,”2017.

13

[Online].Available:http://www.awtti.com/armor-ball-cover/.

[23] Total Plastic Solutions, “ShadeBalls:Anunusual (andoftenmisunderstood) application forplastics,” 2015. [Online]. Available: http://www.totalplasticssolutions.com.au/shade-balls-unusual-often-misunderstoodapplication-plastics/.

[24] K.Mattsson, L.-A. Hansson, and T. Cedervall, “Nano-plastics in the aquatic environment,”Environ.Sci.Process.Impacts,vol.17,no.10,pp.1712–1721,2015.

[25] A.L.Andrady,“Microplasticsinthemarineenvironment,”Mar.Pollut.Bull.,vol.62,no.8,pp.1596–1605,2011.

[26] CleanEnergyFinanceCorporation,“TheAustralianbioenergyandenergyfromwastemarket,”no.November,pp.1–15,2015.

[27] K.Pickerel,“FightingDirty:ManualWashingvs.AutomaticCleaningofSolarModules,”SolarPower World, 25-Feb-2015. [Online]. Available:https://www.solarpowerworldonline.com/2015/02/fighting-dirty-manual-washing-vs-automatic-cleaning-of-solar-modules/.

[28] DepartmentoftheEnvironmentandEnergy,“AustralianEnergyStatistics,TableO,”2017..

[29] A.Blakers,B.Lu,andM.Stocks,“100%renewableelectricityinAustralia,”Energy,vol.133,pp.471–482,Aug.2017.

[30] World Energy Council, “Solar,” 2018. [Online]. Available:https://www.worldenergy.org/data/resources/resource/solar/.

[31] M. M. Mekonnen, P. W. Gerbens-Leenes, and A. Y. Hoekstra, “The consumptive waterfootprintofelectricityandheat:aglobalassessment,”Environ.Sci.WaterRes.Technol.,vol.1,no.3,pp.285–297,2015.

[32] Murray Darling Basin Authority, “Discover surface water.” [Online]. Available:https://www.mdba.gov.au/discover-basin/water/discover-surface-water.

[33] Snowy Hydro, “Dams of the Snowy Mountains Scheme.” [Online]. Available:http://www.snowyhydro.com.au/our-energy/hydro/the-assets/dams/.

[34]Meldrum,S.Nettles-Anderson,G.HeathandJ.Macknick,"Lifecyclewateruseforelectricitygeneration: a review and harmonization of literature estimates" Environmental Research Letters, Vol 8, No 1

14

Appendix

Figure3:AverageannualpanevaporationinAustralia[19]

Table5:SnowyHydroDams,heights,crestlengthandgrosscapacity[33]

NAME TYPE HEIGHT(m) CRESTLENGTH(m)

GROSSCAPACITY(103m3)

Talbingo Rockfill 161.5 710 920,600Eucumbene Earthfill 116.5 579.1 4,798,400Blowering Rockfill 112.2 807.7 1,632,400Geehi Rockfill 94.1 265.2 21,100TumutPond ConcreteArch 86.3 217.9 52,800Jindabyne Rockfill 71.6 335.3 689,900Tooma Earthfill 67.1 304.8 28,100IslandBend ConcreteGravity 48.8 146.3 3,020Tumut2 ConcreteGravity 46.3 118.9 1,500Tantangara ConcreteGravity 45.1 216.4 254,100Jounama Rockfill 43.9 518.2 43,500Murray2 ConcreteArch 42.7 131.1 1,760Guthega ConcreteGravity 33.5 139 1,550

15

HappyJacks ConcreteGravity 29 76.2 270DeepCreek ConcreteGravity 21.3 54.9 5Khancoban Earthfill 18.3 1066.8 21,500

Table6:SnowyHydroofficialareavsmodelarea[33]andGoogleEarth

Officialarea(ha) Areaduringmodelperiod(ha)

Historicalimagedate

Talbingo 1,936 180 31/10/13Eucumbene 14,542 7,500 18/4/11Blowering 4,460 1,300 31/10/09Geehi 700 48 24/2/12TumutPond 203 84 3/3/10Jindabyne 3,034 2,600 27/10/11Tooma 180 129 18/4/11IslandBend 327 13 22/10/12Tumut2 182 182 NotavailableTantangara 2,118 282 16/4/10Jounama 3,804 200 31/10/13Murray2 190 12 5/11/13Guthega 19.4 12 24/2/12HappyJacks 5 0 3/3/10DeepCreek 2 2 NotavailableKhancoban 4,694 275 31/10/09

Table7:TasmanianHydrowaterbodyreservoirareas,fromGoogleEarth

Lake km2 Lake km2

TrevallynPond 1.3 19/11/09 BronteLagoon 4.4 14/3/10LakeMackenzie 0.98 19/11/09 Bradys/Binneys/Tungatinah 8.57 14/3/10LakeRowallan 7.84 27/3/11 LaughingJackLagoon 2.81 27/1/12LakeParangana 0.93 22/11/10 LakeLiapootah 1.98 14/3/10LakeCethana 3.75 22/11/10 WayatinahLagoon 2 14/3/10LakeBarrington 6.38 15/12/07 LakeCatagunya 1.56 14/3/10LakeGairdner 0.77 22/11/10 LakeRepulse 1.17 14/3/10LakePaloona 1.4 22/11/10 ClunyLagoon 1.4 19/1/12LakeAugusta 6.27 27/3/11 MeadowbankLake 5.67 11/3/10ArthursLake 57.4 13/9/10 LakeBurbury 45.5 13/9/13GreatLake 137 27/3/11 LakeMargaret 1.5 16/1/12LittlePineLagoon 1.78 14/3/10 WhitespurPond 0.1 19/1/12ShannonLagoon 2.1 14/3/10 LakeNewton 0.4 19/1/12PenstockLagoon 1.42 2/9/11 LakePlimsoll 3 19/1/12WoodsLake 11.3 11/3/10 LakeMurchison 3.1 19/1/12LakeStClair 26.3 27/3/11 LakeMackintosh 27.9 19/10/11LakeKingWilliam 36.7 25/2/12 LakeRosebery 6.59 25/12/13

16

LakeEcho 36.5 28/3/10 LakePieman 4.86 14/2/12DeeLagoon 6 28/3/10 LakePedder 230 7/3/13PineTierLagoon 0.65 14/3/10 LakeGordon 201 8/2/10