EnergyStorageExcellentComprehensiveEnergyStorageTechnologyCrudeoil$81on3/26/10InOtherNews...Texas-SizeBatteryThehoped-forremedyisabattery,aTexas-sizebattery,whichcouldeventuallyendupplayinganimportantroleinwideruseofgreenpowergenerationsuchassolarandwind.TheU.S.$25millionsystem,whichisnowchargingandissettobededicatedApril8,willbethelargestuseofthisenergystoragetechnologyintheUnitedStates.Thefour-megawattsodium-sulfur(NaS)batterysystemconsistsof80modules,8,000pounds(3,600kilograms)each,constructedbytheJapanesefirmNGK-Locke.TheywereshippedtoLongBeach,California,inDecemberandtransportedtoTexasaboard24trucks.Thecostofthebatterysystemincludes$10millionjusttoconstructthebuildinginwhichitwillbehousedandthenewsubstationitrequires.Overview:EnergyStorageEnergyisstoredtouseitatadifferenttimethanwhenitwasgeneratedTheprocessofconvertingtheenergytostorableformmeansthatsomeenergyislostduetoinefficiencyandheatAdditionalenergyislostwhentheenergyisreleasedorrecoveredduetoasecondinefficiencyIdeally,storageisavoidedtohaveamoreefficientprocessTime-of-daymeteringislikelyinthefutureasmeteringbecomeselectronicandinexpensive(likeathermostat)Shiftingtheenergyfromusagepeakstolow-usetimeshelpstheutility,andcustomerswouldberewardedbylowercharges0AboutThisPresentation18.1General18.2History18.3Flywheels18.4Ultracapacitors18.5PumpedHydro18.6CompressedGasStorage;H218.7Superconductors18.8IceStorage18.9FinancialStorage18.10RenewableEnergyFunding18.11IssuesandTrends18.0ConclusionRenewableenergyisoftenintermittent(likewindandsun),andstorageallowsuseataconvenienttimeCompressedair,flywheels,weight-shifting(pumpedwaterstorage)aredevelopingtechnologiesBatteriesaretraditionalforsmallsystemsandelectricvehicles;gridstorageisafinancialalternativeEnergymaybestoredfinanciallyascreditsintheelectrical“grid”“Netmetering”providesthesamecostas

saledollarstothesupplier;37states’law;

newlawneededinFlorida1EnergyStorage2BatteryHistoryAlessandroVoltamadeprimarybatteriesofdissimilarmetals(silver,zinc,andasaltwaterwetpaperbetweenthem)about1800(trytouchingadimeandanickelincontacttoyourtongue)Theywere“piled”up,andbecameknownasavoltaicpile(fromwhencecametheatomicpile)JohannRitterdevelopedarechargeable(secondary)cellabout1802,buttherewasnogeneratortorechargethemyetGeorgeLeclanche’“wet”cellsusedcarbonrodsandzincHemadeawetpastethatcouldbesealedintothecell,thusmakingaconvenientportableenergysource;nospillingIn1860,thesecondaryorrechargeablebatterywasfurtherdevelopedbyRaymondGastonPlanté(leadsheets&acid)Aleadpasteontheplatesprovidedmoreactivesurfaceareaandallowedlongerdischargelifein1881(Faure)Germansmadethegel-cellwithasealedcasein19602ElectrochemicalBatteriesBatteries(groups;fromartilleryguns)ofcellsareusedseparatelyorinacasecontainingseveralcells;a12Vcarbatteryhassix2VcellsinsidethecaseLargebatteriesareoftenuseseparate2VcellsplacednexttoeachotherinarectangleVariouscellchemistriesareusedLead-acid;Nickel-cadmium;LithiumNickel-metalhydrideZinc-airBestsuitedtostorageperiodsof1secondto60daysSelf-dischargeandsulphationoccurwithtimeDesulphatorcircuitscanreducesulfatesforlongerlife2FlowBatteriesFlowbatteriesusepumpedelectrolytesthatmoveoutsideofthebatterycasePolysulfideBromide(PSB),VanadiumRedox(VRB),ZincBromine(ZnBr),andHydrogenBromine(H-Br)batteriesareexamplesA“fillingstation”couldexchangespentelectrolytefornew“charged”electrolyteThepowerandenergyratingsarethusindependentsincethepowerisfromthebatteryelectrodeswhiletheelectrolytemaybereplacedperiodically3FlywheelsFlywheelsstoreenergyasangularmomentumBestsuitedtostorageperiodsof1secondto10minutesHightemperaturesuperconductingbearingsreducebearingfrictionto2%ofspeeddropperdayBallbearingsaresoinexpensivethattheperformancegainsofmagneticbearingsareirrelevantTheflywheelcaseisdesignedwithashieldtocontainafailedrotoranditspiecesifitshattersandblowsupBatteriesaremuchcheaperthanflywheelsystemsTestbusesusedflywheelsthatwerespunupbyelectricityatbusstops;nowiresalongstreets3Flywheels&TrainsThistracksideflywheelsystemprovidesstabilizationofvoltagesonthetracksystembybeingbothmotorandgeneratorSimilartypesareusedtostabilizerenewableenergyoutputsBuseshavebeenoperatedthatuseflywheelschargedbyelectricityatthebusstops,thusavoidingthecostofoverheadtrolleywires4UltracapacitorsUltracapacitorsareveryhighcapacitanceunitsBestsuitedtostorageperiodsof0.1secondto10secondsStoredenergyis0.5CV2Capacitancesnowreach2.7kF(kilofarad)Carbonelectrodesurfaceareas1000m2to2000m2pergramprovidehighcapacitanceElectrolytesaresulfuricacidorpotassiumhydroxide5HydroPumpedStorageSpecialturbinescanruneithertospinanalternatorortoactasapumpThisreversibilityallowsexcesselectricalenergytobeusedtopumpwatertoahigherstoragereservoirtobeusedasanenergysourcelaterSince2.31ftofelevationhasabottompressureofonepoundpersquareinch(psi),aheadheightof200ftisequivalentto86psiJapanbuilta30MWseawaterpumpedhydrosystematYanbaruin1999Worldwide,pumpedhydroisabout90GW,~3%oftotalstorage,themostwidespreadhigh-energystoragetechnique5SanLuis,California“Eachoftheeightpumping-generatingunitshasacapacityof63,000horsepower[47MW]asamotorand53,000kilowattsasagenerator.AsapumpingstationtofillSanLuisReservoir,eachunitlifts1,375cubicfeetpersecondat290feettotalhead.Asageneratingplant,eachunitpasses1,640cubicfeetpersecondatthesamehead.”

BureauofReclamationNotethedisparitybetweenmotorandgenerator!?!Perhapsstreamflowintostorage?5HydroExamplesPumpedhydrosystemsareinstalledworldwide,buttherearelimitedlocationswherenewdamsmaybeinstalledOppositiontodamsisincreasing,thuspoliticalratherthantechnicalfactorsarerestrictingthenewinstallations6CompressedAirPumpedStorage"Theworld'sfirstcompressedairenergystorageplantwasinGermany,"LeeDavis(plantmanagerfortheCompressedAirEnergyStorage(CAES)PowerPlantinMcIntosh,Alabama)."TheAlabamaCAESplantwasthefirstintheUnitedStateswhenitopenedin1991.“Electricalmotorscompressairto1078psiwithinundergroundsaltcaverns(100MW);heatislostinthecavernOnrelease,naturalgasisburnedtoheattheairagain,whichthenpassesthroughaturbine,spinninganalternator(326MWe)TheNortonEnergyCompanyplansasimilarsiteusinganabandonedlimestonemine35milessouthofCleveland,Ohio6.1CompressedAirEnergyStorage

6.2CompressedH2andNGStorageHydrogenisnormallystoredin8-inchtubesandtanksH2pressuresrangefrom2000to10,000psiNickel-metalhydrideisasolidpelletorpowderstorageCNGorcompressednaturalgasisstoredat3000psi6.3LiquidAirEnergyStorageMitsubishiHeavyIndustriesisdevelopingLASE(LiquidAirStorageEnergy)ThesystemmakesliquidairatnightsandweekendsforvaporizationandelectricitygenerationTheturbineisbaseduponarocketmotorpumpThisload-shiftingprovidestheeconomicincentivetousethesystemCouldalsobedonewithliquidnitrogenstorage7SuperconductorsSinceasuperconductorhasessentiallyzeroresistance,acurrentoncestartedwillflow“forever”Atalatertime,energycouldbeextractedfromthesuperconductorSincethesuperconductorsmustbekeptfarbelowusualairtemperature(~20Kto80K),energymustbeusedtocompressthegasandmakeitliquefyNewersuperconductorsarebeinginvestigatedtofindoneswithahighercriticaltemperaturenearroomtemperature7SuperconductorExampleAcurrentisinducedinthesuperconductortoroidbyinsertingamagnetbrieflyOncereplacedintheliquidnitrogen,thecurrentcirculationcanbedetectedbyacompassCurrentdecayisontheorderof50%in1020years8IceThermalEnergyStorageAirconditioningsystemshaveahighafternoonloadtooffsetthesunheatingofthebuildingandthehigheroutsidetemperatureFreezingiceduringthenightprovidesalatentheatabsorberatlowerenergyprices,assumingdemandchargesortime-of-useratesareimposedDuringtheday,theiceismeltedastherefrigerantiscondensedasitpassesthroughpipesintheiceTheoverallprocessthusprovidesairconditioningatalowercostBaysideHighSchoolinPalmBayFLusesthismethod9FinancialStorageStorageofenergyasacreditfromtheutilitycompanycanbethemostefficientmethodNobatteriesarerequiredwithgridintertie,butmightbeusedtoprovidebackuppowerInnetmeteringstates,asingleelectricalenergymeterisusedEnergyflowmovesthemeterhigherforpurchasedenergyandlowerforenergysoldfromthelocalsiteTheutilitycompanycanavoidmeter-readingcostsbyreadingthemeteronceayearSincethevaluesareonlyinaccountingbooks,thereisnoenergyloss(likelyusedbytheneighbors)However,~16stateshaveyettoregulatethecharges,andsomeutilitiesmaypay$0.023/kWhbutcharge$0.07orhigherThenonnet-meteringsystemshouldbedesignedtoreducethebilltonearlyzerobutneversellenergyintotheutilitysystem10RenewableEnergyFundingPresidentClintonservedfrom1992through2000During1992-1999,theDept.ofEnergyRenewableEnergybudgetvariedfrom$388Mto$488M,reachingitslowof$363Min1997The1999DOEREbudgetshowsthesetopareas:ElectricEnergySystems $38MGeothermal $33MHydrogenResearch $24MHydropower $4MSolarEnergywasseparatedoutat$112Mto$87Min1997to$ 116Min1999Themajorbudgetitemin1999wasbiofuels$89M,followedbyPVat$79MBudgetat4/2007at~$307Mvs.~$200M11IssuesandTrendsEnergystorageprovidesenergyatadifferenttimethanwhenitwasgenerated(time-shifting)ConventionalstoragesystemssuchasbatteriesandpumpedhydrocontinuetodominateduetocostShort-termstorageorenergy-smoothingdeviceslikeflywheelsandultracapacitorsworkwellinthe10-secondtimerangeUnneededgeneratorsareoftenkeptin“spinningreserve”,motoringwithoutloadtoactasgeneratorsifadditionalpowerisrequired(airandbearinglosses)Thisalsostoresreactivepower(v.a.r.sorvars)Energystoragewillsmoothpeaksandvalleysofavailability,butloadshiftingbytheusersismoreusefulConclusion:EnergyStorageEnergystorageistobeavoidedduetothelosses,butmaybeeconomicwhenloadtime-shiftingisp