电力存储五分钟指南

Fiveminuteguide:ElectricityStorageTechnologies Fiveminuteguide ElectricityStorageTechnologies Theneedforstorage Storageneed Revenuestream Requireddischargetimeframe Requiredstoragecapacity Theabilitytomatchgenerationanddemand.Shiftgeneratedenergyfromoffpeaktimestowhenitisneeded.Gridlevelandsmallscaledomesticapplications. Pricearbitrage,reductionindemandcharges Minutes-Hours kW-MW Peakingplantsareneededinordertomeetchangesinsupplyanddemandconditions.Storagecouldprovidethiscapacityincertaincircumstancesandreducetheneedforfossilfuelpeakingplants. Electricsupplycapacity–powercapacitycontractandpricearbitrage Hours MW Increasetheefficiencyofthermalgenerationbyensuringaconstantoutput.Storagecanprovidetheseloadfollowingservices. Loadfollowing–powercapacitycontract Minutes-Hours MW Storagecanbeusedtoreconcilemomentarydifferencesbetweensupplyanddemand.Storagecanbothadsorbandprovideenergyprovidingatwofoldservice. Balancingservices–powercapacitycontract Seconds-Minutes MW Storagecanprovidereservecapacitythatcanbecalleduponintheeventoftheusualelectricitysupplyresourcesbecomingunexpectedlyunavailable. Electricsupplyreserve Hours MW Tomaintainvoltageandfrequencyattherequiredlevelsfollowingalargedisturbancerequiresafastresponse.Storagecanprovidethisservice. Regulationresponseandvoltagesupport–Avoidedpenaltiesfromsystemoperator Milliseconds-Seconds kW-MW EnergystorageusedfortransmissionsupportimprovesT&Dsystemperformancebycompensatingforelectricalanomaliesalmostinstantly. Transmissionnetworksupport–Avoidedpenaltiesfromsystemoperator Milliseconds-Seconds kW-MW Transmissionsystemsarebecomingcongestedduringperiodsofpeakandoffpeakdemand.Storagecanbeusedtomitigatethisissueinsteadofinvestmentinnewtransmissionassets. Assetupgradedeferral–Avoidedcostofinfrastructureinvestments Hours kW-MW Storagetoprovideenergyintheeventofasystemfailureuntilthesystemisrestoredoralternativeenergysourcesareavailable. Electricservicereliability–Reducingproduction/operatinglosses Hours kW-MW Hours Applicationandtechnologyoverview PumpedHeatStorage SodiumSulphurBattery Seconds 1kW10kW100kW1MW10MW100MW1GW EnergyStorageDeviceSize FastResponseSystems eries CAES AdvancedLead-AcidBattery SodiumNickelChlorideBattery ttery High-PowerFlywheels High-PowerSupercapacitors NiMH NiCd Lead-AcidBattery Li-ionBa High-EnergySupercapacitors FlowBatt SMES PumpedHydro LiquidAirStorage DistributionScale-VaryingCapacity/DurationNeeds DischargeTimeatRatedPower Minutes GridScaleLargeCapacity/LongDuration SodiumSulphur(NaS)Batteries TechnologyDescription Asodiumsulphurbatteryisamoltenstatebatteryconstructedfromsodium(Na) andsulphur(S).Thebatterycasingisthepositiveelectrodewhilethemoltencoreisthenegativeelectrode.Thebatteryoperatesathightemperaturesofbetween300-350°C,whilelowertemperatureversionsareunderdevelopment.Incharging,thesodiumionsaretransportedthroughtheionselectiveconductortotheanodereservoir.Dischargeisthereverseofthisprocess.Becausesodiumionsmoveeasilyacrosstheionselectiveconductor,butelectronscannot,thereisnoself-discharge.Whennotinusethebatteriesaretypicallyleftunderchargesothattheywillremainmoltenandbereadyforusewhenneeded.Ifshutdownandallowedtosolidify,areheatingprocessisinitiatedbeforethebatteriescanbeusedagain. Advantages -Highenergydensity -Longlifecycle -Quickresponse -Efficientincharge-dischargecycles -Abletotolerateahighnumberofcharge/dischargecycles Disadvantages CrosssectionofaNaSbattery Terminal ElectricalInsulation MoltenSodium IonSelectiveConductor SodiumElectrode SolidSulphurElectrolyte SulphurElectrode CellContainer -Heatingmayberequired -Potentialsafetyissueswiththemoltensodium -FireissueataJapaninstallationApplications Thereareover300gridapplicationsofNaS batteriesworldwide,withthemajorityoftheselocatedinJapan.NaSbatteriescanbeused formanygridapplicationssuchas:powerqualityapplications,gridstabilisationandtheintegrationofrenewableenergysources. In2019,UAEintegrated15systemsacross10locations,peakingoutatatotalcapacityof108MW/648MWh. SankeyDiagram EnergyInput Costs£/kWh=£330-£1000 EnergyOutput80-82% Electrical+chemical+heatinglosses(Heatinglossescanprovidetherequiredheat) ~18-20% Source:Lazard’sLevelizedCostOfStorage2016 Thebatteriesstoretheenergygeneratedatnightandcombinethiswiththewindfarmoutputduringthetimesofgreaterdemandintheday. FlowBatteries Flowbatteryprocessdiagram PowerInput(Charge)&Load(Discharge) PositiveElectrodeSide Cell NegativeElectrodeSide ElectrolyteTank ElectrolyteTank Pump Ion-SelectiveMembrane Pump TechnologyDescription Flowbatteriesarearechargeablebatteryusingtwoliquidelectrolytes,onepositivelychargedandonenegative,astheenergycarriers.Theelectrolytesareseparatedusinganion-selectivemembrane,whichundercharginganddischargingconditionsallowsselectedionstopassandcompletechemicalreactions.Theelectrolyteisstoredinseparatetanksandispumpedintothebatterywhenrequired.Thestoragecapacityofflowbatteriescanbeincreasedbysimplyutilisinglargerstoragetanksfortheelectrolyte.Severalchemistriesarepossibleforthebattery. Electro