储能电站分析-英

StationaryBatteryEnergyStorage

Systems

AnalysisAfocusonintradayshiftingMarch2023ContentsPreface33Commercialisationconsiderations10AnoteontheanalysisAnalysis1313171921Technical

comparisonCommercialcomparisonEnvironmentalcomparisonSafetycomparisonSummary4Recommendations4Definitions567ContextConclusionandrecommendationsAppendix222325ExamplesofBESSprojectsandinstallationsTechnologies

andmanufacturersLithiumionbatteries888999ReferencesRedox

flowbatteries(RFB)MoltensaltbatteriesOthermetalbatteriesNon-metalbatteriesPrefaceAnoteontheanalysisThepurposeofthisdocumentistoprovideatechnicalandcommercialcomparisonofvariousbatteryenergystoragesystem(BESS)chemistrieswhicharecurrentlyavailableonthemarketsuitableforintradayshifting.TheanalysispresentedinthisdocumentwasconductedinternallybyAraAke

inQ42022,andassuch,onlyshowsasnapshotoftheBESSmarketintime.DuetothesignificantgrowthandinnovationoccurringintheBESSmarket,dependinguponwhenthisdocumentispickedupbythereader,

theresultsthroughoutregardingthechemistriespresentedmaybeoutofdate.WhensuchaBESSiscombinedwithanintermittentrenewableenergysystemwithnoinherentstorage(wind,solar,

run-of-the-riverhydro),throughouttheday,theresultinghybridsystemcandivertanyexcess

energyproducedattimesoflowdemandtostorage.TheBESScansubsequentlysupplythegridattimesofhighdemand,whilstalsominimisingtheuseoffossilfuelswhenattemptingtomatchpeakdemandandovercomenetworkconstraints.3SummaryRenewableenergyisNewZealand’slargestsourceofelectricitygeneration(82%)•

Nickel-hydrogenisdesignedforuptothreecharge/dischargecyclesperday,

yetisalsocapableofdischargeratesvaryingbetween2and12hours.Competitorshavesimilarcharge/dischargerates,butareonlydesignedforamaximumofonetotwocyclesperdaybeforesignificantlyimpactingbatterylifetime.andprovidesapproximately41%ofNewZealand’sprimaryenergysupply.

Of1theinstalledrenewableelectricitycapacity,

20%isassociatedwithintermittentrenewableenergysystems(IRES)withlittletonocapacityforenergystorage.2•

Fromacostperspective,nickel-hydrogenisthebestvaluefor12hoursorlessofstoragewhencomparingthelevelisedcostofstorage(LCOS)ofthetechnologies,ameasureofthetotalcostofanenergystoragesystemagainsttheenergydischargedoverthebattery’slifetime.ThereispotentialtoovercomethisissuebycombiningIRESwithstationaryenergystoragesystems(i.e.batteries).Withthiskindofhybridsystem,throughintradayshifting,anyexcess

energyproducedbytheplantattimesoflowdemandmaybestoredtosubsequentlysupplythegridattimesofhighdemand,whilstalsominimisingtheuseoffossilfuelswhenattemptingtomatchpeakdemandandovercomenetworkconstraints.•

Theestimatedenvironmentalimpactofthebatteryiscomparabletoanumberofcompetitors,butsignificantlylowerthanlithiumion.AraAke

hasidentifiedanumberofpotentialIRESpowerplantswithinNewZealandtodemonstratesuchahybridsystem.Lithiumiontechnologydominatesthebattery•

Thenickel-hydrogentechnologyhaspassedallrelevantbatterysafetystandards,includingtheUL9540Atestforthermalrunaway.Manynewbatterytechnologieshavepassedthistest,however,

fewlithiumionmanufacturershavewithonlyasinglecontainerisedlithiumionbatterymanufacturerintheUL9540Adatabase(EVLO).marketacrossmostsectors,

includingrenewableenergystorage,butitisofinterestto3AraAke

tounderstandthetechnicalandcommercialcharacteristicsofallthevariousbatterysolutionsavailableonthemarket,aswellasthesafetyandenvironmentalimpactsofthesetechnologies.•

Themanufacturer,EnerVenue,

hasbeenbackedbymultibilliondollarengineeringcompany,Schlumberger(marketedasSLB),whowillsupportlarge-scaledeploymentofnickel-hydrogenbatterytechnologyacrossselectedglobalmarkets.Currentproductionvolumeis60MWh/year,howeverplannedfacilitiessoontobeunderconstructionwillresultinexceeding2GWh/yearbytheendof2024.RecommendationsOfthemorethan10containerisedBESSstudied,nickel-hydrogen(NiH

)isastandout2Anotherbatterytechnologywhichcouldbeofinterestiscalcium-antimony(CaSb),givenitshighenergyoutputandlowLCOS

similartonickel-hydrogen.Noenvironmentaldataforthistechnologywasavailable,butallthingsconsidered,itcouldbeaninterestingtechnologyforsimilarapplications.chemistryforstorageof12hoursorlesswhenconsideringallaspectsduetoauseablelifetimeof30yearsand30,000charge/dischargecycles.•

Onafootprintbasis,nickel-hydrogeniscompetitiveintermsofuseableannualenergyoutputwithhigherenergydensitylithiumionandmoltensaltbatterychemistries.Onalifetimebasis,nickel-hydrogenhasamongthehighestenergyoutputofalltechnologiesstudied,beatingallmanufacturers,buttwolithiumionofferings(CATL

andTesla).4DefinitionsElectricalcurrent(A)Rated

poweroutput(kW)C-rating(hours-1)Theflow(andamount)ofelectricityinanelectricalcircuit,measuredinamperes.1

A

isequaltoanelectricalflowrateof6.241509074×10¹⁸electronspersecond.Thetheoreticalmaximumamountofinstantaneouspower,

measuredinkilowatts,whichcanflowintooroutofabattery.Thecharge/dischargerateisameasureofhowmuchtimeisrequiredtofullychargeordischargeabattery.NotethattheC-ratingofabatteryimpactspoweroutpute.g.a120kWhbatterywithaC/2ratingwillprovide60kWofpowerover2hours.AC/12equivalentwouldprovide10kWover12hours.Electricalresistance(Ω)Rated

batterycapacityorenergyoutput(kWh)Theoppositiontoflowofelectricalcurrentinacircuit,measuredinOhms.Atheoreticalmeasureofbatterypowerdeliveredoveragiventimeperiodi.e.1kWh

isequivalentto1kW

ofconstantpowerovertheperiodof1hour.

1kWh

isalsoequivalentto3.6megajoules(MJ).BatterycycleVoltage

(V)Theprocessofchargingabatteryanddischargingitasrequired.Asinglechargeanddischargeisequivalentto1cycle.Theelectromotivedrivingforceinanelectricalcircuit,measuredinVolts.

Voltageistheproductofcurrentandresistance.Round

tripefficiency(%)Thepercentageofenergyusedtochargethebattery(i.e.putintostorage)whichcanthenbelaterretrieved.Thisisessentiallyameasureoftheenergylostduringagivencharge-dischargecycle.Lifetimedegradation(%/lifetime)Electricalpower(W)Aprocesswhichpermanentlyreducestheamountofenergyabatterycanstore,ortheamountofpoweritcandeliver.

Usuallypresentedonapercycleorperyearbasis.Therateelectricalenergyistransferredbyanelectricalcircuit,measuredinwatts.Poweristheproductofvoltageandcurrent.Useablebatterycapacity(kWh)Theactualbatterypowerdeliveredoveragiventimeperiod,onceaccountingforroundtripefficiency.Batterylifetime(yearsorcycles)BatteryBatterylifetimeisequivalenttothenumberofcyclesbeforethebatterywilleithernolongerholdchargeorperformanceissignificantlyreduced.Thislifetimemayalsobeconvertedtoyears.Adevicecontaininganelectriccelloraseriesofelectriccellsstoringenergythatcanbeconvertedintoelectricalpower.5ContextRenewableenergyisNewZealand’slargestsourceofelectricitygeneration(82%)andprovidesapproximately41%ofNewZealand’sprimaryenergysupply.1Ofthe7682MWofrenewableelectricitycapacityinstalledinNewZealandbytheendof2021,1703MWaregeneratedbyintermittentrenewableenergysystems(IRES).Suchsystemsinclude:2•

Run-of-theriverhydropower(586MW),

whereelectricityisgeneratedfromwater3flowinginariverorstream(asopposedtoconventionalhydrowhichgeneratespowerfromthegravitationalpotentialenergyofdammedwater)†;•

Wind(913MW),whereturbinesgenerateelectricityfromthewind’skineticenergy;and•

Solar(205MW),wherephotovoltaic(PV)cellsconvertsunlightintoelectricalenergy.Thekey

differencebetweentheabovesystemsandconventionalhydropowerandgeothermalplantsisthattheyhavelittletonocapacityforenergystorageandaresubjecttoambientconditionssuchasseasonalriverflow,

windspeed/directionandsolarradiation.Thismakestheseplants’electricitysupplyirregularwiththeinabilitytoco-ordinateelectricaloutputwithconsumerdemand.ThereispotentialtoovercomethisissuebycombiningIRESwithstationaryenergystoragesystems(i.e.batteries).Withthiskindofhybridsystem,throughintradayshifting,anyexcess

energyproducedbythepowerplantattimesoflowdemandmaybestoredtosubsequentlysupplythegridattimesofhighdemand.Havingaccesstothisstoredrenewableenergywillminimisetheuseoffossilfuelswhenmeetingpeakdemandandalsohasthepotentialtoprovidemoreeffectiveembeddedgeneration,tomatchpeakloadandnetworkconstraints.AraAke

hasidentifiedanumberofpotentialIRESpowerplantswithinNewZealandtodemonstratesuchahybridsystemtosupportintradaygenerationshiftingandlinescompanyconstraintmanagement.Lithiumiontechnologydominatesthebatterymarketacrossmostsectors

,includingrenewableenergystorage,butitisofinterestto4AraAke

tounderstandthetechnicalandcommercialcharacteristicsofallthevariousbatterysolutionsavailableonthemarket,aswellasthesafetyandenvironmentalimpactsofthesetechnologies.†ThereisanargumentthatanumberofNewZealand’slargeconventionalhydroelectricplantsareessentiallyrun-of-the-riverbecauseoftheirlimitedstorage,howeveradistinctionismadethatiftheriverisimpoundedtocreateareservoirofsignificantsizethentheplantistechnicallynotrun-of-the-river.56ExamplesofBESSprojectsandinstallationsBytheendof2021,theinstalledcapacityofgrid-scaleBESSaroundtheworld•

InJanuary2023,RWE,a

Germanenergyprovider,commissioned117MW,128MWhexceeded

16GWandglobalinvestmentsapproached$10billionUSD6.Somerecentoflithiumionbatteriesacrosstwooftheirrun-of-the-riverplants.10

ThesystemsatGersteinwerkinWerneandEmslandstationinLingenhaveenergycapacitiesof79MWhand49MWhrespectively.Throughtheseinstallations,RWEcanmakeadditionalelectricitycapacityavailabletothegridandalsobalancetheflowofenergyfromthepowerstations,helpingtokeepthefrequencyofthepowergridstable.examples

ofbothdomesticandinternationalrenewableenergybatterystoragehybridprojectsinclude:•

InMarch2022,WELNetworksandInfratecannouncedthattheyhadenteredintomajorcontractsforthesupplyandbuildofNewZealand’sfirstrenewableenergyBESShybrid7.Alongwiththeproposedbatteryfacility,consistingofa35MW•

NewZealandgentailer,MeridianEnergy,announcedinDecember2022thatconstructionoftheRuakākāBESSatMarsdenPointwillbegininQ12023.11

Uponcompletionandcommissioning(expectedH22024),the100MW,200MWhSAFTlithiumionunitwillbehybridisedwitha

new130MWsolarPVplanttoreducecosts.12lithiumionunitfromSAFT,

anewsolarfarmisbeingexploredtoreducethecostofrenewablepowerforconsumers.ConstructionbeganinAugust2022and,oncecommissioned,thefacilitywillstoreenoughenergytomeetthedailydemandsofover2,000homesandwillbecapableofprovidingfastreservessupportfortheNorthIslandgrid.•

PortlandGeneralElectriccommissionedtheUnitedStates’firstfacilitytoco-locatewindandsolargeneration,coupledwithbatterystorage,inSeptember2022.13

TheWheatridgeRenewableEnergyFacilityhasa

300MWwindfarm,a

120MWsolarfarmanda120MWhlithiumionBESS.Atmaximumoutput,thefacilitylocatednearLexington,OregonproducesmorethanhalfofthepowerthatwasgeneratedbyOregon’slastcoalplant(demolishedthesamemonththisfacilitybecameoperational)orenoughemissions-freeenergytopowerabout100,000

homes.14•

AESChilesubmittedanEnvironmentalImpactAssessmentinlateFebruary2023foran$800MUSDhybridparkintheAntofagastaregion.Theprojectwillinvolvetheconstructionofa

140MWwindfarm,252MWofsolaranda623.5MW,

3,100MWhlithiumionBESS

.ThisproposedBESShybridfollowsonfromthe2019installation8ofa10MW,

50MWhlithiumionenergystoragesystematits178MWhrun-of-the-riverhydropowerfacilityattheCordilleraComplexnearSantiago,Chile.Priortothis2019installation,AESChile(thenAESGener)conductedananalysisonarangeofstorageoptions,finallychoosinglithiumionbatteriesbecausethetechnologyisscalingexponentiallyandwasmostfavourableintheirassessmentwhenconsideringfactorsincludingcost,safety,energydensity,charginganddischargingrates,andoverallTheexampleslistedherereflectthatlithiumionbatterystoragecurrentlyexhibitsacleardominanceintherechargeablebatterymarket,accountingformorethan90%ofallBESSdeploymentsinboth2020and2021.

Thisdominancehoweverislikelydue6toa

varietyoffactors,suchasmanufacturingcapability,asmanynewertechnologiescapableofcompetingwithlithiumionona

technicalandcommercialleveldonotyethavethemanufacturingcapacitytosupplylargeMW-scaleenergystoragesystems.lifecycle.97TechnologiesandmanufacturersAnanalysishasbeenconductedonstationary,

longdurationbatterysolutionssuitableforapplicationtointermittentrenewableenergysystems.Redox

flowbatteries(RFB)InRFBs,redox(reductionandoxidation)reactionswithinelectrochemicalcellsenablesenergytobestoredinaflowingliquidelectrolytesolutionduringbatterychargeanddischarge.Batterypowerisdependentuponthesizeoftheelectrochemicalstack,whereasbatteryenergydependsuponthevolumeofelectrolyte.Thisseparationofpowerandenergyisakey

distinctionandadvantageofRFBswhencomparedtootherelectrochemicalstoragesystemsassystemvulnerabilitytouncontrolledenergyreleaseislimitedbysystemarchitecturetoafewpercentofthetotalenergystored.22Atypical20ftcontainerisedBESSproducinggreaterthan100kWhofenergy,over12hoursorless,hasbeenusedasabaselineforthisanalysis,soonlyperceivedcompetitorstosuchaproducthavebeenincluded.Thebatterysolutionsandmanufacturerswhichhavebeenidentifiedaredetailedinthesubsequentsection.Althoughidentifiedhere,somecompaniesassociatedwiththetechnologiesofinterestdonotprovidesufficientinformationtoallowforanykindofanalyticalcomparisonbetweenproductsandthereforehavenotbeenincludedintheanalysis.Vanadium

(VRFB)•

CellCube23•

InvintyEnergySystems24•

Rongke

Power25•

VRBEnergy26LithiumionbatteriesLithiumionbatteriesutilisesolidelectrodesoftypicallycarbonandmetaloxidewithaliquidorganicelectrolytecontainingadissolvedmetalsalt.Metalionstravelbetweenelectrodesviaaporousmembrane,generatinganelectricalcurrent.15Thetwomostcommonchemistriesarelithiumironphosphate(LFP)andnickelmanganesecolbolt(NMC).ManufacturersaremovingmoretowardstheformerasdespiteNMCtypicallyhavingahigherenergydensity,LFPischeapertoproduce,hasalongerlifecycleandislesssusceptibletothermalrunaway.Zinc-Bromide(ZnBr

flow)2•

Redflow27Zinc-Air•

Zinc828Lithiumion•

CATL16Ironflow(IFB)•

ESS29•

CorvusEnergy17•

Eaton18Organic(non-metal)•

CERQ(formerlyJenaBatteries)30•

EVLO19•

SAFT20•

Tesla218MoltensaltbatteriesZinc-Bromide(ZnBr

non-flow)2Typicallyaredoxflowbatterychemistry,oxidationreductionchemistryoccursbetweenzincandbromideelectrodesviaeitherasolidgeloraqueouselectrolyteallowingzincionstoflowthroughamembrane,subsequentlygeneratingcurrent.Thesebatteriesoperatewellinexcess

of100

Candtheanodeandcathodeare0typicallyliquidseparatedbyasaltelectrolyteorceramicmembranecapableofconductingmetalionstogenerateanelectricalcurrent.•

EOSEnergyEnterprises36•

Gelion37Calcium-Antimony(CaSb)•

Ambri31Lead

(Pb)Sodium-Nickel-Chloride(NaNiCl

)2Interestingly,nolead-basedbatterieshavebeenidentifiedinthisparticularspace,likelyduetothechemistry’slowenergydensity,shortlifetimeand,asaresult,highpricewhencomparedtolithium-ion,thedominantchemistryintoday’sbatterymarket.•

FZSoNick32SodiumSulphur(NaS)•

NGKInsulators33Non-metalbatteriesOthermetalbatteriesConductivepolymerSolidcarbon-graphenehybridelectrodescombinedwithaliquidelectrolyteandapermeableseparatingmembraneenableionstotravelbetweentheanodeandcathode,creatingelectricalcurrent.Nickel-Hydrogen(NiH

)2Nickelhydroxideandnickelalloyelectrodesinthepresenceofanalkalineelectrolytecreateanelectricalcharge,producingandconsuminghydrogengasonchargeanddischarge.•

PolyJoule38•

SLB(partneredwithEnerVenue)34,359CommercialisationconsiderationsTheprevioussectiondetailsasubsetoftheplayersinthestationaryBESSmarket,howeveranimportantdiscussionpointbeyondthechemistryishowfarthroughthecommercialisationjourneyareeachofthesechemistriesand/orcompanies.Figure1:Technology

Readiness

Level

(IEA)Table

1detailsanumberofkey

commercialisationmetricswhichhavebeenidentifiedacrossthemanufacturerslistedintheprevioussection.Thesemetricsincludeyearfounded,installedbatteryvolume(inMWh),numberofemployees,revenue(in$MUSD,ifany),annualproductionvolumeandtotalagreedprojectpipeline(bothinMWh).SomeimportantthingstonoteisthatanumberofthesecompanieshavebusinessinterestsoutsideofstationaryBESS,sothenumberspresentedmaynotnecessarilybeadirectresultoftheiractivitiesrelatedtoBESS.Also,althoughtheremaybeasignificantdifferenceinsomevaluespresentedwhencomparedtoothermanufacturers,thisdoesnotnecessarilymeanthattheyareatdifferentstagesofcommercialisation,itmaysimplyreflectothermarketindicatorssuchasmarketshare(i.e.twoBESScompanieswith200and2000employeesmaybesimilarlycommercialisedwithinthemarket.Athirdcompanywith20employeesislikelysignificantlylesscommercialised).Nevertheless,themetricspresentedprovidereasonableproxiestoindicateacompany’sstageofcommercialisation.Similarlytotheprevioussection,althoughidentified,somecompaniesassociatedwiththetechnologiesofinterestdonotprovidesufficientcommercialinformationinthepublicdomaintoallowforanykindofanalyticalcomparisonbetweenproductsandthereforehavenotbeenincluded.Inthemajorityofcases,eachcompanypresenteddoesnotdetaileachandeverymetricofinterestinthepublicdomain,howevertheydoprovideenoughtomakeaneducatedcomparison.Estimatesofcommercialisationstagemaybemappedagainstthe11-pointtechnologyreadinesslevel(TRL)scalepresentedbytheInternationalEnergyAgency(seeFigure1).3910TherangewhichisrelevanttothemanufacturersincludedisestimatedtobeTRL7toTRL11,pre-commercialdemonstrationtomatureinmarket:TRL11:Matureinmarket

(verylargeproductvolumesmanufactured,deliveredanddemonstratedinfieldi.e.>1GWh,revenuelikely>$50MUSD)•

CATL•

CorvusEnergy•

NGKInsulators•

Rongke

Power•

SAFT•

TeslaTRL10:Earlyadoptioninmarket

(largeproductvolumesmanufactured,deliveredanddemonstratedinfieldi.e.100MWh-1GWh,revenuelikely$10M-$50MUSD)•

CellCube•

EOSEnergyEnterprises•

FZSoNick(acquiredbyHitachiChemical-$5.8BUSDrevenuein2021)SometakeawaysfromthisTRLmappinginclude:TRL9:Commercialoperation(significantproductvolumesmanufactured,deliveredanddemonstratedinfieldi.e.10MWh-100MWh,revenuelikely$1M-$10MUSD)•

Oldertechnologies,withfewerrecentdevelopments,suchaslithiumion,vanadiumflowandmoltensodiumbatteriesarehigheruptheTRLscale.•

InvintyEnergySystems•

VRBEnergy•

Ofthenewertechnologies,EOSEnergyEnterprises(non-flowzinc-bromide)appearstohaveasignificantcommercialadvantageoveritscompetitors,generatingover$10MUSDinrevenuein2022withatleasta1.8GWhprojectpipeline.TRL8:Commercialdemonstration(smallproductvolumesunderdemonstrationwithsignificantgrowthinmanufacturingi.e.1MWh-10MWh,revenuelikely$100K-$1MUSD)•

CompanieslowerontheTRLscale(TRL7-8)willhaveasignificantnumberofcommercialisationbarriers(forexample,manufacturingandsupplychain)tocrossbeforegainingearlyadoptioninthemarket.Thiswillbesignificantlymorechallengingforindependentcompanieswhencomparedto,forexample,EnerVenue(nickel-hydrogen),whohavebackingfromglobal,multibilliondollarengineeringcompany,Schlumberger(nowmarketedasSLB).•

Ambri•

EnerVenue

(globallybrandedasSLB-$28.1B

USDrevenuein2022)•

ESS•

RedflowTRL7:Pre-commercialdemonstration(onlysmallproductvolumesmanufactured,deliveredanddemonstratedinfield,minimalorpre-revenue)•

Gelion•

PolyJoule•

Zinc811Table

1:CommercialmetricsofbatterymanufacturersChemistryManufacturerFoundedYearDispatchedvolumeMWhEmployees#Revenue*ProductionvolumeMWh/yearPipelinevolumeMWh$MUSD/year170,000(Additional140,000peryearunderconstruction)Approx.33,000CATLCorvusEnergySAFT201120091918-400-14,36440----61(2020)41192>1,000Lithiumion170,000(Total

plannedproductionby2025)780>4,000128,000(58MforBESS)4281,462(10,000non-automotive)43Tesla2003>17,00040,000(Megapackonly)CellCubeInvintyEnergySystemsRongke

PowerVRBEnergy20082020200820072008201542.928.0992>3061171-4.09(2019)44---3.245-66.3Vanadium300--652505062->500EOSEnergyStorageGelion64018.40.43461.12478002>1,800Pilotscale>2#--Zinc-basedRedflow2005800(Goaltogenerateby2024)481(Ambitionof60MWhby2024)Zinc82011Pilotscale44-FZSoNick49NGKInsulators51ESS2011191920114004,100-13020,10018332.2(2019)5040411001,000750-Sodium-based-Ironflow0.8752>12,00053200(200,000cellsbyendof2023)Calcium-AntimonyAmbri2010Commercialpilot#122->1,2005460(2,200plannedby2024;31,000by2027)Nickel-HydrogenOrganicEnerVenue

(SLB)PolyJoule20202011CommercialpilotPilotscale11011-->5,00055<1>1(10000cells)*RevenuedatahasbeengainedfromGoogleFinanceQ32021toQ32022,unlessspecifiedotherwise.Unknowndatanotavailableinthepublicdomainhasbeenindicatedwithadash.Pilotscalereferstoinstallationslessthan1MWh.Commercialpilotreferstoinstallationsbetween1–2MWh.#12AnalysisThedatapresentedinthissectioniseitherpubliclyavailableorhasbeengainedthroughdirectconsultationwiththemanufacturer.

Forthosetechnologieswithmultipleplayers(i.e.lithiumionandvanadiumflow),batterydatahasbeenaggregatedandaveragevaluesarepresented.Theraw,

non-aggregateddataisprovidedintablesintheAppendix.Figure2:Effectiveenergydensityofbatterytechnologies150Technical

comparisonEffectiveenergydensityTheenergydensityofbatteriesistypicallypresentedinwatt-hourspergram(Wh/gorkWh/kg).Thisprovidesareasonablecomparisonwhentheuseableenergyoutputandweightofthebatteryisknown,however,

inthecaseofcontainerisedenergystoragesystems,thereissignificantvoidagewithinthecontainerforthepurposeofmaintenance,airflowetc.Thismeansthatonlyaneffectiveenergydensitycanbedeterminedusingtheuseableenergyoutputandtheweightofthecontainerisedsystem.100500Thisapproachisalsochallengingassomemanufacturersdonotprovidetheweightofthecontainerisedsystem,however,

allprovidetheareafootprintofthesystemforagivenenergyoutput,enablinganeffectiveenergydensityofkWh/m

tobepresented2inFigure2.Notethatanadvantageofcontainerisedsystemsisthattheymaybestacked,however,

forthepurposeofthiscomparison,thefootprintdensityhasonlybeenpresentedforasystemwithasinglecontainer.Lithiumionhasthehighestaverageenergydensityofthetechnologiescomparedatapproximately145kWh/m

.Thisobservationisnotsurprisingaslithiumionisknown2forhavingaparticularlyhighenergydensitywhencomparedtootherrenewablebatterytechnologies.56

Thisisthenfollowedbymolten-saltbatteries(calcium-antimony,sodium-nickel-chloride,sodium-sulphur),whicharealsoknownforhighenergydensities,57

atapproximately80kWh/mflowandnon-flowbatteryconfigurations,hasaneffectiveenergydensityof30kWh/.Thisdensityissimilartonickel-hydrogen(25kWh/m

),butmuchhigherthanotherflowchemistries(Vanadium,10kWh/m

;Iron,15kWh/m

).Duetoitsearlystageof2.Zinc-brominetechnology,inbothm2222development,theconductivepolymerbatteryhasalowenergydensityof15kWh/msimilartoverylargeredoxflowsystems.2,13Batterycyclingnickel-hydrogentechnology(>1000MWh/m2-lifetime)whilstthefourremaininglithium-lifetime.ionproductshaveoutputsoflessthan650MWh/m2Thelifetimeofabatteryismeasuredbythetotalnumberofcharge/dischargecyclesabatterycanachievebefore:Onanannualbasis,duetohavinghighenergydensities,lithiumionhasthehighestenergyoutput(43MWh/m

-year,

aggregated;76MWh/m2-year,Tesla),

followedbythemoltensaltcalcium-antimonybattery(30MWh/m

-year).Interestingly,despitehavingarelativelylowenergydensity,nickel-hydrogenhasthethirdhighestoutputof24MWh/m

-year(joint

withsodium-nickel-chloridemoltensalttechnology)duetothetechnology’scapabilitytocyclethreetimesperday.2•

Thebatterycannolongerholdacharge;or2•

Significantenergycapacitydegradationhasoccurred.2Ofthebatterytechnologiesinvestigated(seeFigure3),nickel-hydrogeniscapableofachievingatleast30,000cyclesinitslifetime.Thisisfollowedbyvanadiumandironredoxflowbatterieswithlifetimesofapproximately20,000cycles