先进材料与器件 用于固定电能 存储应用

AdvancedMaterialsandDevicesforStationaryElectricalEnergyStorageApplications

DECEMBER2010

SPONSOREDBY

U.S.DepartmentofEnergy,OfficeofElectricityDeliveryandEnergyReliability

AdvancedResearchProjectsAgency—Energy

ORGANIZEDBY

SandiaNationalLaboratories

PacificNorthwestNationalLaboratory

TheMinerals,Metals&MaterialsSociety(TMS)

PREPAREDBY

ABOUTTHISREPORT

ThisreportwassupportedbySandiaNationalLaboratoriesandPacificNorthwestNationalLaboratoryonbehalfoftheU.S.DepartmentofEnergy’s(DOE)OfficeofElectricityDeliveryandEnergyReliabilityandtheAdvancedResearchProjectsAgency-Energy(ARPA-E).

ThisdocumentwaspreparedbySarahLichtner,RossBrindle,LindsayKishter,andLindsayPackofNexightGroupunderthedirectionofDr.WarrenHunt,ExecutiveDirector,TheMinerals,Metals,andMaterialsSociety(TMS).ThecooperationofASMInternationalthroughtheEnergyMaterialsInitiative,aswellastheAmericanCeramicSociety,theElectrochemicalSociety,andtheMaterialsResearchSociety,isgratefullyacknowledged.

ADVANCEDMATERIALSANDDEVICESFORSTATIONARYELECTRICALENERGYSTORAGEAPPLICATIONS

Notice:ThisreportwaspreparedasanaccountofworksponsoredbyanagencyoftheUnitedStatesgovernment.NeithertheUnitedStatesgovernmentnoranyagencythereof,noranyoftheiremployees,makesanywarranty,expressorimplied,orassumesanylegalliabilityorresponsibilityfortheaccuracy,completeness,orusefulnessofanyinformation,apparatus,product,orprocessdisclosed,orrepresentsthatitsusewouldnotinfringeprivatelyownedrights.Referencehereintoanyspecificcommercialproduct,process,orservicebytradename,trademark,manufacturer,orotherwisedoesnotnecessarilyconstituteorimplyitsendorsement,recommendation,orfavoringbytheUnitedStatesgovernmentoranyagencythereof.TheviewsandopinionsofauthorsexpressedhereindonotnecessarilystateorreflectthoseoftheUnitedStatesgovernmentoranyagencythereof.

CONTENTS

ExecutiveSummary 1

IntroductionandProcess 5

EnergyStorage:TheNeedforMaterialsand

DeviceAdvancesandBreakthroughs 7

IntegratingEnergyStorage

intotheElectricGrid 11

AMaterials-BasedApproachto

AdvancingEnergyStorageTechnologies 15

AdvancedLead-AcidandLead-CarbonBatteries 17

Lithium-IonBatteries 21

Sodium-BasedBatteries 25

FlowBatteries 29

PowerTechnologies 33

EmergingTechnologies 37

ThePathForward 41

References 43

WorkshopReportContributors 45

ADVANCEDMATERIALSANDDEVICESFORSTATIONARYELECTRICALENERGYSTORAGEAPPLICATIONS

1

EXECUTIVESUMMARY

EXECUTIVESUMMARY

Reliableaccesstocost-effectiveelectricityisthebackboneoftheU.S.economy,andelectricalenergystorageisanintegralelementinthissystem.Withoutsignificantinvestmentsinstationaryelectricalenergystorage,the

currentelectricgridinfrastructurewillincreasinglystruggletoprovidereliable,affordableelectricity,jeopardizingthetransformationalchangesenvisionedforamodernizedgrid.InvestmentinenergystorageisessentialforkeepingpacewiththeincreasingdemandsforelectricityarisingfromcontinuedgrowthinU.S.productivity,shiftsinandcontinuedexpansionofnationalculturalimperatives(e.g.,thedistributedgridandelectricvehicles),andtheprojectedincreaseinrenewableenergysources.

StationaryenergystoragetechnologiespromisetoaddressthegrowinglimitationsofU.S.electricityinfrastructure.Avarietyofnear-,mid-,andlong-termstorageoptionscansimultaneouslyprovidemultiplebenefitsthathavethepotentialtogreatlyenhancethefutureresilienceoftheelectricgridwhilepreservingitsreliability.Thesebenefitsincludeprovidingbalancingservices(e.g.,regulationandloadfollowing),whichenablesthewidespreadintegrationofrenewableenergy;supplyingpowerduringbriefdisturbancestoreduceoutagesandthefinanciallossesthataccompanythem;andservingassubstitutesfortransmissionanddistributionupgradestodeferoreliminatethem.

Significantadvancesinmaterialsanddevicesareneededtorealizethepotentialofenergystoragetechnologies.Currentlarge-scaleenergystoragesystemsarebothelectrochemicallybased(e.g.,advancedlead-carbonbatteries,lithium-ionbatteries,sodium-basedbatteries,flowbatteries,andelectrochemicalcapacitors)andkinetic-energy-based(e.g.,compressed-airenergystorageandhigh-speedflywheels).Electricpowerindustryexpertsanddevicedevelopershaveidentifiedareasinwhichnear-terminvestmentcouldleadtosubstantialprogressinthesetechnologies.Deployingexistingadvancedenergystoragetechnologiesintheneartermcanfurthercapitalizeontheseinvestmentsbycreatingtheregulatoryprocessesandmarketstructuresforongoinggrowthinthissector.Atthesametime,along-termfocusontheresearchanddevelopmentofadvancedmaterialsanddeviceswillleadtonew,morecost-effective,efficient,andreliableproductswiththepotentialtotransformtheelectricgrid.

STRATEGICPRIORITIESFORENERGYSTORAGEDEVICEOPTIMIZATIONTHROUGHMATERIALSADVANCES

Advancedmaterials,deviceresearchanddevelopment,anddemonstrationsarerequiredtoaddressmanyofthechallengesassociatedwithenergystoragesystemeconomics,technicalperformance,anddesignthatmustbeovercomeforthesedevicestomeettheneedsandperformancetargetsoftheelectricpowerindustry.Theadvancementoflarge-scaleenergystoragetechnologieswillrequiresupportfromtheU.S.DepartmentofEnergy(DOE),industry,andacademia.Figure1outlinesthehigh-priorityresearchanddevelopmentactivitiesthatarenecessarytoovercomethelimitationsoftoday’sstoragetechnologiesandtomakegame-changingbreakthroughsintheseandothertechnologiesthatareonlynowstartingtoemerge,suchasmetal-airbatteries,liquid-metalsystems,regenerative

fuelcells,advancedcompressed-airenergystorage,andsuperconductingmagneticelectricalstorage.Thepriorityactivitiesoutlinedinthisreportfocusonunderstandinganddevelopingmaterialscoupledwithdesigning,developing,anddemonstratingcomponentsandsystems;however,thereisalsorecognitionthatthisworkneedstobedoneinthecontextofstrategicmaterialsselectionandinnovativesystemdesign.

STRATEGICMATERIALSSELECTIONimpliesthatwhilesignificantcostreductioninstorageisparamountandmaterialsmakeupthelargestportionofsystemcost,itiscriticalthatstoragedevicesutilizematerialsthatarebothlowerincostandabundantintheUnitedStates.Newmaterialsdevelopmentcanexpandtheoptionsavailabletoequipmentdevelopers,potentiallyofferingimportantcostandperformanceadvantages.

INNOVATIVEDESIGNSofstoragetechnologiescandrivethedevelopmentofdevicesthatcanbeaffordablymanufacturedatgridscale.Designsimplificationsanddesignsforefficientmanufacturingcanenablestoragesystemstobeproducedatlowercostsviaautomatedmanufacturingwithnecessaryqualitycontrolprocesses.Effectivesystemdesignalsoensuresthatcontrolsystemsandpowerelectronicsenableefficient,secure,andreliableinteroperabilitywiththeelectricgrid.

ThesuccessoftheseactivitiesandinitiativeswillrequiresignificantsupportfromDOE.TohelpDOEbetterfocusitsresourcesovertime,Figure1dividesthesolutionsforeachstoragetechnologybythetimeframeinwhichtheywillimpactthemarket:nearterm(lessthan5years),midterm(5–10years),andlongterm(10–20years).CommittingtotheseactivitieswillallowDOE,technologydevelopers,andtheelectricpowerindustrytopursueacoherenttechnologydevelopmentanddemonstrationstrategyforenergystoragetechnologiesingrid-scaleapplications.

FIGURE1:PRIORITIZEDACTIVITIESTOADVANCEENERGYSTORAGETECHNOLOGIES

ADVANCEDLEAD-ACIDANDLEAD-CARBONBATTERIES

LITHIUM-IONBATTERIES

NEARTERM(<5years) MIDTERM(5–10years) LONGTERM(10–20years)

ConductDOE-fundedvalidationtestsofsystemlifetime,ramprates,etc.

Understandpoormaterialsutilizationthroughdiagnosticsandmodeling

Develophigh-power/energycarbonelectrodeforlead-carbonbattery

Developmodelsforiontransportthroughsolids(inorganicsolids,polymers)

Developnewintercalationcompoundswithlowcyclingstrainandfatigue;aimfor10,000cyclesat80%depthofdischarge

Conductexperimentstodevelopaquantitativeunderstandingofcatastrophiccellfailure

anddegradation

Designandfabricatenovelelectrodearchitecturestoincludeelectrolyteaccesstoredoxactivematerialandshortionandelectrondiffusionpaths(e.g.,non-planargeometries)

Developahighlyconductive,inorganic,solid-stateconductorforsolid-stateLi-ionbatteries

Developrobustplanarelectrolytestoreducestacksizeandresistance

Decreaseoperatingtemperature,preferablytoambienttemperature

Developatruesodium-airbatterythatprovidesthehighestvalueinalmostanycategoryofperformance

Implementpilot-scaletestingofbatterysystemstodevelopperformanceparametersforgridapplications

Usesurface-sciencetechniquestoidentifyspeciesonsodium-ionanodesandcathodes

SODIUM-BASEDBATTERIES

2 ADVANCEDMATERIALSANDDEVICESFORSTATIONARYELECTRICALENERGYSTORAGEAPPLICATIONS

EXECUTIVESUMMARY

EMERGINGTECHNOLOGIES

POWERTECHNOLOGIES

CROSSCUTTING

ACTIVITIES

FLOWBATTERIES

NEARTERM(<5years) MIDTERM(5–10years) LONGTERM(10–20years)

Establishacenterforstackdesignandmanufacturingmethods,includingjointandsealdesign

Improvemembranestoenableminimumcrossover,lowersystemcost,increasedstability,andreducedresistance

Developnon-aqueousflowbatterysystemswithwidercelloperatingvoltagestoimproveefficiency

Developlow-cost,formable,chemicallyandthermallytolerantresinsforpiping,stacks,andtanks

Improvemasstransportviaatailoredcatalystlayerandflowfieldconfigurationstoincreaseoperatingcurrentdensityandreducesystemcostperkilowatt

Developaninline,real-timesensorthatcandetectimpuritiesinelectrolytecompositionforvariousflowbatterychemistries

Createacomputationalfluidicscenteratanationallaboratoryoruniversity

Identifylow-costhydrogensuppressionmaterials(anti-catalysts)andredoxcatalystsfornegativeelectrodes

Developa1-megawattflywheelmotorcapableofvacuumoperationandsuperconduction

Optimizematerialsutilizationthroughdiagnosticsandmodeling

Develophigh-power/energycarbonelectrodeforelectrochemicalcapacitors

Develophublessflywheelrotorwithfourtimeshigherenergy

Improvethermalmanagementinendothermicelectrolysisreactionsandexothermicfuelcellreactionsinregenerativefuelcells

Developnewcatalystsformetal-airbatterieswithlowoverpotentialsforoxygenreductioninordertomakesystemsmoreefficient,cost-effective,andbifunctional

Exploretheuntappedpotentialofmultivalentchemistries

Developairelectrodesformetal-airbatterieswithhighelectrochemicalactivityandlowerpolarizationandresistance

Combinetechnologiesforsynergy

Takeanintegratedapproachtodegradationbycombiningmicrostructure/chemistryobservationswithmechanisticmodeling(bothdegradationandelectrochemicalmodels)andacceleratedtesting

ConductDOE-fundeddemonstrationsofallenergystoragetechnologies

Specifycycleandlifetestsforstationarypowerapplications

3

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ADVANCEDMATERIALSANDDEVICESFORSTATIONARYELECTRICALENERGYSTORAGEAPPLICATIONS

PAGE

5

WORKSHOPPARTICIPANTSPRIORITIZEENERGYSTORAGEACTIVITIESANDINITIATIVESTHROUGH2030.

INTRODUCTIONANDPROCESS

INTRODUCTIONANDPROCESS

Cost-effectiveenergystoragetechnologiesareakeyenablerofgridmodernization,addressingtheelectricgrid’smostpressingneedsbyimprovingitsstabilityandresiliency.InvestmentinenergystorageisessentialforkeepingpacewiththeincreasingdemandsforelectricityarisingfromcontinuedgrowthinU.S.productivity,shiftsinandcontinuedexpansionofnationalculturalimperatives(e.g.,emergenceofthedistributedgridandelectricvehicles),andtheprojectedincreaseinrenewableenergysources.Materials,theirprocessing,andthedevicesintowhichtheyareintegratedwillbecriticaltoadvancingcleanandcompetitiveenergystoragedevicesatthegridscale.

CurrentresearchanddemonstrationeffortsbytheU.S.DepartmentofEnergy(DOE),nationallaboratories,electricutilitiesandtheirtradeorganizations,storagetechnologyproviders,andacademicinstitutionsprovidethefoundationfortheextensiveeffortthatisneededtoacceleratewidespreadcommercialdeploymentofenergystoragetechnologies.Forgrid-scalestoragetobecomepervasive,theelectricpowerindustry,researchersofadvancedmaterialsanddevices,equipmentmanufacturers,policymakers,andotherstakeholdersmustcombinetheirexpertiseandresourcestodevelopanddeployenergystoragesystemsthatcanaddressthespecificstorageneedsoftheelectricpowerindustry.

Seekingtoacceleratethecommercializationofstationaryenergystorageatgridscale,TheMinerals,Metals&MaterialsSociety(TMS)joinedwiththeDOEOfficeofElectricityDeliveryandEnergyReliability,theDOEAdvancedResearchProjectsAgency-Energy,PacificNorthwestNationalLaboratory,andSandiaNationalLaboratoriestosponsorafacilitatedworkshop.Thisworkshopwasdesignedtogarnercriticalinformationfromkeystakeholderstodevelopapathforwardforgrid-scaleenergystorage.

Thirty-fivestakeholdersandexpertsfromacrossthematerialsscienceanddevicecommunitiesattendedtheworkshoponJune21–22,2010,inAlbuquerque,NewMexico.Immediatelyprecedingtheadvancedmaterialsanddevicesworkshop,stakeholdersandexpertsfromtheelectricpowerindustry,research,andgovernmentcommunitiescametogether

toidentifytargetsforenergystoragetechnologiesinspecificgridapplications,whichresultedintheworkshopreport,ElectricPowerIndustryNeedsforGrid-ScaleStorageApplications.Theparticipantsoftheadvancedmaterialsanddevicesworkshopusedthetargetsdeterminedinthepreviousworkshoptoidentifythelimitationsofexistingenergystoragetechnologiesandtheadvancesnecessaryforthesedevicestoachievewidespreadcommercialization.

Whileallenergystoragetechnologiesandsystemswerewithinthescopeoftheworkshop,themainfocuswasontechnologiesforwhichDOEinvolvementcouldaccelerateprogresstowardcommercialdeploymentatgridscale.Thetimeframeunderconsiderationwaspresentdaythrough2030,withparticularemphasisonthe1-to5-yearand5-to10-yeartimeframes.

Basedontheresultsoftheworkshop,thisreportprovidesguidancetoDOEforadvancingthefollowingenergystoragetechnologies:

Advancedlead-acidandlead-carbonbatteries

Lithium-ionbatteries

Sodium-basedbatteries

Flowbatteries

Powertechnologies(e.g.,electrochemicalcapacitorsandhigh-speedflywheels)

Emergingtechnologies(e.g.,metal-airbatteries,liquid-metalsystems,regenerativefuelcells,andadvancedcompressed-airenergystorage)

ThereportsfromtheseworkshopswillinformfutureDOEprogramplanningandultimatelyhelptocommercializeenergystorageatgridscale.

40-MEGAWATTENERGYSTORAGEFACILITYINFAIRBANKS,ALASKA

ENERGYSTORAGE:THENEEDFORMATERIALSANDDEVICEADVANCESANDBREAKTHROUGHS

ENERGYSTORAGE:THENEEDFORMATERIALSANDDEVICEADVANCESANDBREAKTHROUGHS

ElectricitydemandintheUnitedStatesissteadilyrising;in2009,electricityconsumptionwasmorethanfivetimeswhatitwas50yearsago.1Thisdemandisprojectedtoincreaseby1%peryearthrough2035.2Tomeettheincreasedelectricitydemandsexpectedby2035(excludingthoseexpectedfromtheintroductionofelectricvehicles),anadditional250gigawattsofgeneratingcapacitywillhavetobeaddedtotheelectricitygenerationinfrastructure.3However,theagingelectricgriddoesnothavetheabilitytotransmittheselargeamountsofelectricityfromthepointofgenerationtotheenduserortoaccommodatetheproposedincreasesingenerationfromrenewablesourceslikewindandsolar.4Advancedstoragetechnologieshavethepotentialtofulfillapplicationsacrosstheentiretyofthegridtoaddressthesegrowingissues.Tomeetincreasingelectricitydemandswhilecontinuingtoprovideconsumerswithelectricityatthelevelofcostandreliabilitytheyhavecometoexpect,theU.S.electricgridrequiresimmediateandcost-effectiveupdates.

StationaryenergystoragetechnologiespromisetoaddressthegrowinglimitationsofU.S.electricityinfrastructureandmeettheincreasingdemandforrenewableenergyuse.Withavarietyofnear-,mid-,andlong-termstorageoptions,energystoragedevicescansimultaneouslyprovidemultiplebenefitsthathavethepotentialtogreatlyenhancethefutureresilienceoftheelectricgridwhilepreservingitsreliability.Thesebenefitsincludeprovidingbalancingservices,suchasregulationandloadfollowing;supplyingpowerduringbriefdisturbancestoreduceoutagesandthefinanciallossesthataccompanythem;andservingassubstitutestohelpdeferoreliminatetransmissionanddistributionupgrades.

Significantadvancesinenergystoragematerialsanddevicesareneededtorealizethepotentialofthesetechnologies.Industrymembersanddevicedevelopershaveidentifiedareasinwhichshort-terminvestmentcouldleadtosubstantialprogress.Deployingexistingadvancedenergystoragetechnologiesintheneartermcanfurthercapitalizeontheseinvestmentsbyencouragingutilityoperatingexperienceandacceptance.Atthesametime,along-termfocusontheresearchanddevelopmentofadvancedmaterialsanddeviceswillleadtonew,lower-cost,andmoreefficientandreliableproductswiththepotentialtorevolutionizetheelectricgrid.

THECURRENTSTATEOFENERGYSTORAGETECHNOLOGIES

Storagetechnologiescurrentlybeingresearched,developed,anddeployedforgridapplicationsincludehigh-speedflywheels,electrochemicalcapacitors,traditionalandadvancedlead-acidbatteries,high-temperaturesodiumbatteries(e.g.,sodium-sulfurandsodium-nickel-chloride),lithium-ionbatteries,flowbatteries(e.g.,vanadiumredoxandzincbromine),compressed-airenergystorage,pumpedhydro,andotheradvancedbatterychemistries,suchasmetal-air,nitrogen-air,sodium-bromine,andsodium-ion.

Thegridapplicationsforthesetechnologiescanbelooselydividedintopowerapplicationsandenergymanagementapplications,whicharedifferentiatedbasedonstoragedischargeduration.Technologiesusedforpowerapplicationsaretypicallyusedforshortdurations,rangingfromfractionsofasecondtoapproximatelyonehour,toaddressfaultsandoperationalissuesthatcausedisturbances,suchasvoltagesagsandswells,impulses,andflickers.Technologiesusedforenergymanagementapplicationsstoreexcesselectricityduringperiodsoflowdemandforuseduringperiods

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ADVANCEDMATERIALSANDDEVICESFORSTATIONARYELECTRICALENERGYSTORAGEAPPLICATIONS

ofhighdemand.Thesedevicesaretypicallyusedforlongerdurationsofmorethanonehourtoservefunctionsthatincludereducingpeakloadandintegratingrenewableenergysources.

TABLE1:SUITABLEGRIDAPPLICATIONSANDCURRENTSTATUSOFENERGYSTORAGETECHNOLOGIES5

ThetechnologiesinTable1representthosewiththegreatestpotentialforwidespreadgrid-scaledeployment.Thetableindicatestheapplicationsforwhichthetechnologiesarebestsuitedandprovidesanoverviewofthecurrentdevelopmentandcommercializationstatusofeachtechnology.Whileothertechnologiesarecurrentlyunderdevelopment,theyarenotadvancedenoughforgrid-scaleevaluation.

ENERGYSTORAGETECHNOLOGY

SUITABLEAPPLICATIONS

CURRENTDEVELOPMENTANDCOMMERCIALIZATIONSTATUS

HIGH-SPEEDFLYWHEELS(FW)

Highpotentialforpowerapplications

Currently,FWsareusedinmanyuninterruptedpowersupplyandaerospaceapplications,including2kW/6kWhsystemsusedintelecommunications.

FWfarmsarebeingplannedandbuilttostoremegawattsofelectricityforshort-durationregulationservices.

ELECTROCHEMICALCAPACITORS(EC)

Highpotentialforpowerapplications

SmallECsareamaturetechnology;systemswithahigherenergycapacityarestillindevelopment.

TRADITIONALLEAD-ACIDBATTERIES(TLA)

Highpotentialforpowerapplicationsandfeasibleforenergyapplications

TLAsaretheoldestandmostmatureenergystoragetechnologyavailable.

ThelargestTLAbatterysysteminoperationhasa10MW/40MWhcapacity.

ADVANCEDLEAD-ACIDBATTERIESWITHCARBON-ENHANCEDELECTRODES(ALA-CEE)

Highpotentialforbothpowerandenergyapplications

ALA-CEEsweredevelopedasaninexpensivebatteryforuseinhybridelectricvehicles.

SODIUMSULFURBATTERIES(NaS)

Highpotentialforbothpowerandenergyapplications

Thebatteryhasbeendemonstratedatmorethan190sitesinJapan,totalingmorethan270MWincapacity.

U.S.utilitieshaveinstalled9MWforpeakshaving,firmingwindpower,andotherapplications.Thedevelopmentofanother9MWsystemisinprogress.

SODIUM-NICKEL-CHLORIDE(Na-NiCl2)BATTERIES

Highpotentialforbothpowerandenergyapplications

ThebatteryoperatesatlowertemperaturesthanNaSbatteries.

ENERGYSTORAGE:THENEEDFORMATERIALSANDDEVICEADVANCESANDBREAKTHROUGHS

9

LITHIUM-ION(Li-ION)BATTERIES

Highpotentialforpowerapplicationsandreasonableforenergyapplications

Li-ionbatteriescurrentlydominatetheconsumerelectronicmarket.

Manufacturersareworkingtoreducesystemcostandincreasesafety,enablingthesebatteriestobeusedinlarge-scalemarkets.

ZINC-BROMINEBATTERIES(ZnBr)

Highpotentialforenergyapplicationsandreasonableforpowerapplications

ZnBrbatterieswith1MW/3MWhcapacitieshavebeentestedontransportabletrailersforutilityuse.

Largersystemsarecurrentlybeingtested.

VANADIUMREDOXBATTERIES(VRB)

Highpotentialforenergyapplicationsandreasonableforpowerapplications

VRBbatteriesupto500kW/5MWhhavebeeninstalledinJapan.

Thesebatterieshavebeentestedandusedforpowerapplications,supplyingupto3MWover1.5seconds.

COMPRESSED-AIRENERGYSTORAGE(CAES)

Highpotentialforenergyapplications

ThefirstcommercialCAESplantwasbuiltinGermanyin1978andhasa290MWcapacity.Anadditionalplantwitha110MWcapacitywasbuiltinAlabamain1991.

AdvancedadiabaticCAESsystemsarecurrentlybeingdeveloped.

PUMPEDHYDRO(PH)

Highpotentialforenergyapplications

PHrepresentsapproximately3%ofglobalgenerationcapacity—morethan90GWofPHstorageisinstalledworldwide.

WhilePHhasachievedwidespreaddeployment,allofthesuitablePHlocationsarecurrentlybeingused.

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ADVANCEDMATERIALSANDDEVICESFORSTATIONARYELECTRICALENERGYSTORAGEAPPLICATIONS

TheenergystoragetechnologiesinTable1arecurrentlyatdifferentstagesofdevelopment,demonstration,andcommercialization.Increasingtheamountofinstalledandplannedtechnologiesiscriticaltothewidespreaddeploymentofenergystoragesystemssoonerratherthanlater;forthisreason,manyotherinstallationsareplannedforthenextfiveyears.TheenergyandpowercapacitiesofsomeofthecurrentandplannedworldwideinstallationsareprovidedinFigure2.

FIGURE2:INSTALLEDANDPLANNEDENERGYSTORAGESYSTEMS,APRIL20106

Continuedinvestmentintheresearchanddevelopmentofnewandexistingenergystoragetechnologieshasthelong-termopportunitytorevolutionizetheelectricpowerindustry.Large-scaledemonstrationsofenergystoragesystemsencouragetheutilitybuy-inneededtomakeenergystoragefeasibleatgridscaleandprovideresearchersandtechnologydeveloperswithcriticalperformancedata.Astrategicapproachtothedeploymentofgrid-scaleenergystoragetechnologieshasthepotentialtoprovideacost-effective,near-termsolution.

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INTEGRATINGENERGYSTORAGEINTOTHEELECTRICGRID

INTEGRATINGENERGYSTORAGEINTOTHEELECTRICGRID

Withtheincreasingpenetrationofvariablerenewableenergysources,electricitygenerationisnolongerconstant,yetmustcontinuetomeetfluctuatingelectricitydemands.Thisimbalance,alongwiththecurrentgridlimitationsandaginginfrastructure,hasthepotentialtochallengegridoperatorsastheymanageanincreasinglydynamicelectricgrid.Stationaryenergystoragetechnologiescanbeharnessedforavarietyofapplicationstohelptheelectricpowerindustryprovidecustomerswithreliableandaffordableelectricity.

Energystoragedevicesprovidenecessaryservicestotheelectricgrid,includingbalancingservices(e.g.,regulationandloadfollowing),toreduceoutagesandthefinanciallossesthataccompanythem.Byrespondingtothegridfasterthantraditionalgenerationsources,operatingefficientlyatpartialload,andvaryingdischargetimesdependingonapplicationneed,thesamestoragedevicescanaidinthedeferraloftransmissionanddistributioninfrastructuretokeepelectricityrateslow.

METRICSFORSTORAGETECHNOLOGIESANDAPPLICATIONS

Toprovidethemaximumbenefittoelectricityendusersandgainacceptancefromtheelectricpowerindustry,storagetechnologiesmustmeetcertaineconomic,technicalperformance,anddesigntargetsforenergystorageapplications.Whileeachenergystorageapplicationwillrequiredifferentspecifications,thesethreeinterrelatedfactorsmustbemettoensurethewidespreaddeploymentofgrid-scaleenergystorage.

SYSTEMECONOMICSisthemostimportantmetrictotheelectricpowerindustry.Consumersareaccustomedtohavingelectricitywhentheyneeditandataffordableprices,whichmakesthelifecyclecostofstoragetechnologiescriticaltotheirwidespreadadoption.Somestakeholdersintheelectricityindustrybelievethatanenergystoragetechnologymustbecompetitivewiththecostofcurrentlyavailabletechnologiesusedforpeakelectricitygeneration(e.g.,gasturbines)andmustprovideincreasedefficiencyandotherbenefitsthatadequatelyoffsetcapital,operating,andlifetimecosts.Whilethisviewfailstorecognizethefullbenefitsofenergystorage,somedecisionmakersintheelectricityindustrycontinuetoviewstorageasapeakgenerationsubstituteandvalueitaccordingly.Inordertoachievewidespreadimplementationatgridscale,thecostofstationarystoragedevic