直接空气捕获：实现净零排放的关键技术（英）-IEAVIP专享VIP免费

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Direct Air Capture

A key technology for net zero

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INTERNATIONAL ENERGY

AGENCY

Direct Air Capture Abstract

A key technology for net zero

PAGE | 3

Abstract

Direct air capture plays an important and growing role in net zero pathways.

Capturing CO2 directly from the air and permanently storing it removes the CO2

from the atmosphere, providing a way to balance emissions that are difficult to

avoid, including from long-distance transport and heavy industry, as well as

offering a solution for legacy emissions. Air-captured CO2 can also be used as a

climate-neutral feedstock for a range of products that require a source of carbon.

In the IEA Net Zero Emissions by 2050 Scenario, direct air capture technologies

capture more than 85 Mt of CO2 in 2030 and around 980 MtCO2 in 2050, requiring

a large and accelerated scale-up from almost 0.01 MtCO2 today. Currently

18 direct air capture facilities are operating in Canada, Europe and the United

States. The first large-scale direct air capture plant of up to 1 MtCO2/year is in

advanced development and is expected to be operating in the United States by

the mid-2020s.

This report explores the growing momentum behind direct air capture, together

with the opportunities and challenges for scaling up the deployment of direct air

capture technologies consistent with net zero goals. It considers the current status

of these technologies, their potential for cost reductions, their future energy needs,

and the optimal locations for direct air capture facilities. Finally, the report identifies

the key drivers for direct air capture investment and priorities for policy action.

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DirectAirCaptureAkeytechnologyfornetzeroTheIEAexaminesthefullspectrumofenergyissuesincludingoil,gasandcoalsupplyanddemand,renewableenergytechnologies,electricitymarkets,energyefficiency,accesstoenergy,demandsidemanagementandmuchmore.Throughitswork,theIEAadvocatespoliciesthatwillenhancethereliability,affordabilityandsustainabilityofenergyinits31membercountries,8associationcountriesandbeyond.Pleasenotethatthispublicationissubjecttospecificrestrictionsthatlimititsuseanddistribution.Thetermsandconditionsareavailableonlineatwww.iea.org/t&c/Thispublicationandanymapincludedhereinarewithoutprejudicetothestatusoforsovereigntyoveranyterritory,tothedelimitationofinternationalfrontiersandboundariesandtothenameofanyterritory,cityorarea.Source:IEA.Allrightsreserved.InternationalEnergyAgencyWebsite:www.iea.orgIEAmembercountries:AustraliaAustriaBelgiumCanadaCzechRepublicDenmarkEstoniaFinlandFranceGermanyGreeceHungaryIrelandItalyJapanKoreaLithuaniaLuxembourgMexicoNetherlandsNewZealandNorwayPolandPortugalSlovakRepublicSpainSwedenSwitzerlandTurkeyUnitedKingdomUnitedStatesTheEuropeanCommissionalsoparticipatesintheworkoftheIEAIEAassociationcountries:BrazilChinaIndiaIndonesiaMoroccoSingaporeSouthAfricaThailandINTERNATIONALENERGYAGENCYDirectAirCaptureAbstractAkeytechnologyfornetzeroPAGE3IEA.Allrightsreserved.AbstractDirectaircaptureplaysanimportantandgrowingroleinnetzeropathways.CapturingCO2directlyfromtheairandpermanentlystoringitremovestheCO2fromtheatmosphere,providingawaytobalanceemissionsthataredifficulttoavoid,includingfromlong-distancetransportandheavyindustry,aswellasofferingasolutionforlegacyemissions.Air-capturedCO2canalsobeusedasaclimate-neutralfeedstockforarangeofproductsthatrequireasourceofcarbon.IntheIEANetZeroEmissionsby2050Scenario,directaircapturetechnologiescapturemorethan85MtofCO2in2030andaround980MtCO2in2050,requiringalargeandacceleratedscale-upfromalmost0.01MtCO2today.Currently18directaircapturefacilitiesareoperatinginCanada,EuropeandtheUnitedStates.Thefirstlarge-scaledirectaircaptureplantofupto1MtCO2/yearisinadvanceddevelopmentandisexpectedtobeoperatingintheUnitedStatesbythemid-2020s.Thisreportexploresthegrowingmomentumbehinddirectaircapture,togetherwiththeopportunitiesandchallengesforscalingupthedeploymentofdirectaircapturetechnologiesconsistentwithnetzerogoals.Itconsidersthecurrentstatusofthesetechnologies,theirpotentialforcostreductions,theirfutureenergyneeds,andtheoptimallocationsfordirectaircapturefacilities.Finally,thereportidentifiesthekeydriversfordirectaircaptureinvestmentandprioritiesforpolicyaction.DirectAirCaptureAcknowledgementsAkeytechnologyfornetzeroPAGE4IEA.Allrightsreserved.Acknowledgements,contributorsandcreditsThisreportwaspreparedbytheEnergyTechnologyPolicyDivision,ledbyTimurGuel,intheDirectorateofSustainability,TechnologyandOutlooksattheInternationalEnergyAgency(IEA).TheleadauthorwasSaraBudinis.SamanthaMcCulloch(HeadoftheCarbonCapture,UtilisationandStorageTechnologyUnit)contributedsignificantinputandguidance.ThereportbenefitedfromvaluableinputsandcommentsfromotherexpertswithintheIEA,includingPraveenBains,SimonBennet,FrancoisBriens,MathildeFajardy,AraceliFernandezPales,CarlGreenfield,IlkkaHannula,KaranKochhar,LucaLoRe,SaraMoarif,RachaelMoore,MaxwellPisciottaandUweRemme.CarolineAbettanandMarinaDosSantosprovidedessentialsupport.TheIEACommunicationsandDigitalOfficealsoassistedandcontributedtotheproductionofthefinalreportandwebsitematerials,particularlyAstridDumond,AllisonLeacu,TalineShahinian,ThereseWalshandWonjikYang.ThereportwaseditedbyJustinFrench-Brooks.SeveralexpertsfromoutsidetheIEAwereconsultedduringthedataandinformationcollectionprocessandreviewedthereport.Theircontributionswereofgreatvalue.Theseexpertsincluded:AdamBaylin-SternCarbonEngineeringLeeBeckCleanAirTaskforceChristophBeuttlerClimeworksChrisBolestaDGEnergy,EuropeanCommissionMerritDaileyCarbonDirectTimDixonTechnologyCollaborationProgrammeonGreenhouseGasR&D(GHGTCP/IEAGHG)RyanEdwardsOccidentalPetroleumClaudeGauvinNaturalResourcesCanadaDanHancuUSDepartmentofEnergyGeoffHolmesCarbonEngineeringAnharKarimjeeUSDepartmentofEnergyHiroshiKawakamiMinistryofEconomy,TradeandIndustry,JapanDirectAirCaptureAcknowledgementsAkeytechnologyfornetzeroPAGE5IEA.Allrightsreserved.JasminKemperTechnologyCollaborationProgrammeonGreenhouseGasR&D(GHGTCP/IEAGHG)AnuKhanCarbon180HélènePilorgéUniversityofPennsylvaniaMilesSakwa-NovakGlobalThermostatVivianScottClimateChangeCommittee,UnitedKingdomLouisUzorClimeworksJeffreyWeirGlobalThermostatDirectAirCaptureTablesofcontentsAkeytechnologyfornetzeroPAGE6IEA.Allrightsreserved.TableofcontentsAbstract.....................................................................................................................................3Executivesummary..................................................................................................................8Chapter1.Growinginterestindirectaircapturefornetzero..........................................13Introduction...............................................................................................................................13Theroleofdirectaircaptureinmeetingnetzerogoals...........................................................14Deploymentofdirectaircapturetoday....................................................................................18Chapter2.TechnologiestocaptureCO2fromtheair........................................................21Solidandliquiddirectaircapture.............................................................................................21Emergingdirectaircapturetechnologies.................................................................................24CostofcapturingCO2directlyfromtheair...............................................................................27Chapter3.Keyconsiderationsfordirectaircapturedeployment...................................34Scalingupdirectaircapturevaluechains...............................................................................34Directaircaptureenergyneeds...............................................................................................35Carbonfootprintandcostofcarbonremoval...........................................................................36Waterandlandfootprint...........................................................................................................39Chapter4.Optimallocationsfordirectaircapture............................................................41Capturecostbylocation...........................................................................................................41Energysources........................................................................................................................43Useandstorageofair-capturedCO2.......................................................................................46Chapter5.Directaircaptureaspartofacarbondioxideremovalportfolio...................49Whatiscarbondioxideremoval?.............................................................................................49Whatarethemaincarbondioxideremovaloptions?...............................................................50Chapter6.Scalingupthedeploymentofdirectaircapture..............................................54Supportfordirectaircapture....................................................................................................54Businessmodelsfordirectaircapture.....................................................................................63Sixprioritiesfordirectaircapturedeployment.........................................................................68Annex.......................................................................................................................................73Abbreviationsandacronyms....................................................................................................73Unitsofmeasure......................................................................................................................74ListoffiguresandtablesMapofrenewableenergysourcepotentialandCO2geologicalstorage................................10GlobalCO2capturefrombiomassandDACintheNetZeroScenario...................................15GlobalCO2capturefromDACSandDACwithuseintheNetZeroScenario........................16DirectAirCaptureTablesofcontentsAkeytechnologyfornetzeroPAGE7IEA.Allrightsreserved.Globalenergyconsumption(left)andCO2capture(right)fromDACintheNetZeroScenario....................................................................................................................16DACglobaloperatingcapacity,2010-2021.............................................................................18DACplantsinoperationworldwide..........................................................................................19S-DAC(top)andL-DAC(bottom)configurations....................................................................22KeyfeaturesofS-DACandL-DACtechnologyapproaches...................................................23CO2capturecostatvaryingCO2concentrations,2020..........................................................27Levelisedcostofcaptureatvaryingheat,electricityandCO2prices,DACS(upper)andDACwithCO2use(lower),2020......................................................................................29ContributiontolevelisedcostofDACbytypeofexpenditure,2020.......................................30ContributiontodeclineincostofDACbyhigh-leveldriver.....................................................31PotentialforreductioninCAPEXofDACduetolearningbydoing........................................32EnergyneedsofDACSandDACwithCO2usebytechnologyandCO2destination.............35Operatingtemperatureforvariousheat-generatingtechnologies...........................................36DACScarbonremovalefficienciesbyenergysource.............................................................37DACScostofcarbonremovalbyenergysourceforheatandelectricity,2020......................38LevelisedcostofcapturingcarbonbyDACStechnologyforselectedregions,2030and2050..................................................................................................................................42Levelisedcostofcapturingcarbon(includingUSD250/tcarbonprice)byDACStechnologyandenergysourceforselectedregions,2050........................................................................43MapofrenewableandnuclearenergysourcepotentialandCO2geologicalstorage............45KeyfeaturesofthemainCDRapproachesandtechnologies................................................51DACprojectsindevelopment..................................................................................................54MajorpubliclyfundedDACinitiativesbyregion......................................................................55PolicysupportforandlevelisedcostofDACSin2020and2030,UnitedStates...................57SelectedDACprojectsthatreceivedpublicfundinginEurope...............................................59AnassessmentofDACSashigh-qualityCDR........................................................................64Simplifiedlevelisedcostoflow-carbonfuelsforlong-distancetransport,2020......................68MainpolicyinstrumentsforDACdevelopmentanddeployment.............................................69ListofboxesCDRinIPCCandIEAscenarios.............................................................................................17CompaniesleadingthedevelopmentofDACtechnologies....................................................19TheTRLscale.........................................................................................................................25PublicacceptanceofDAC.......................................................................................................40MineralisationofCO2forpermanentstorage..........................................................................47MainCDRoptions....................................................................................................................52PotentialsourcesoffinanceforDACcompanies....................................................................62DACcertificationandaccountingwithinaCDRportfolio........................................................66DirectAirCaptureExecutivesummaryAkeytechnologyfornetzeroPAGE8IEA.Allrightsreserved.ExecutivesummaryCapturingCO2fromtheaircansupportnetzerogoalsDirectaircapture(DAC)playsanimportantandgrowingroleinnetzeropathways.CapturingCO2directlyfromtheairandpermanentlystoringitremovestheCO2fromtheatmosphere,providingawaytobalanceemissionsthataredifficulttoavoid,includingfromlong-distancetransportandheavyindustry,aswellasofferingasolutionforlegacyemissions.IntheIEANetZeroEmissionsby2050Scenario,DACtechnologiescapturemorethan85MtofCO2in2030andaround980MtCO2in2050,requiringalargeandacceleratedscale-upfromalmost0.01MtCO2today.DACisakeypartofthecarbonremovalportfolio.Carbondioxideremoval(CDR)isnotanalternativetocuttingemissionsoranexcusefordelayingaction,butispartofacomprehensivestrategyfor“net”zero–whereemissionsbeingreleasedareultimatelybalancedwithemissionsremoved.CDRapproachesrangefromnature-basedsolutionssuchasafforestationtotechnology-basedapproachesunderpinnedbycarboncaptureandstorage.DACwithgeologicalCO2storagehasseveraladvantagesasaCDRapproach,includingarelativelysmalllandandwaterfootprint,andhighdegreeofassuranceinboththepermanenceofthestorageandthequantificationofCO2removed.ThecontributionofDACgoesbeyondcarbonremoval.Air-capturedCO2canbeusedasaclimate-neutralfeedstockforarangeofproductsthatrequireasourceofcarbon,frombeveragestochemicalsandsyntheticaviationfuels.IntheNetZeroEmissionsby2050Scenarioaround350Mtofair-capturedCO2isusedtoproducesyntheticfuelsin2050,includingforaviation,supportingoneofthefewoptionsavailabletoreduceemissionsinthesector.MomentumfordirectaircaptureisgrowingDACplantscurrentlyoperateatasmallscale,butwithplanstogrow.Currently18DACfacilitiesareoperatinginCanada,EuropeandtheUnitedStates.AllbuttwoofthesefacilitiesselltheirCO2foruse,andthelargestsuchplant–commissionedinIcelandinSeptember2021–iscapturing4000tCO2/yearforstorage(viamineralisation).Thefirstlarge-scaleDACplantofupto1MtCO2/yearisinadvanceddevelopmentandisexpectedtobeoperatingintheUnitedStatesbythemid-2020s.GovernmentsandindustryaregettingbehindDAC.Sincethestartof2020,governmentshavecommittedalmostUSD4billioninfundingspecificallyforDACDirectAirCaptureExecutivesummaryAkeytechnologyfornetzeroPAGE9IEA.Allrightsreserved.developmentanddeployment.ThisincludesUSD3.5billiontodevelopfourDAChubsandaUSD115millionDACPrizeprogrammeintheUnitedStates.NewR&DfundingisforthcominginAustralia,Canada,Japan,theUnitedKingdomandelsewhere.TheUnitedStatesalsolaunchedaCarbonNegativeShotduringCOP26,identifyingDACamongaportfolioofCDRapproacheswithpotentialtoremoveCO2anddurablystoreit,atscale,forunderUSD100/tCO2.Privateandphilanthropicinvestmentisalsogrowing:leadingDACcompanieshaveraisedaroundUSD125millionincapitalsincethestartof2020andcompaniesrangingfromMicrosofttoUnitedAirlinesareinvestinginearlyprojects.DACisoneoffourtechnologiesthatBreakthroughEnergyCatalystistargetingforuptoUSD1.5billionininvestment,anditisalsoaneligibletechnologyfortheUSD100millionCarbonRemovalXPRIZEannouncedin2021.Costsarehightoday,butprojectedtofallCapturingCO2fromtheairisthemostexpensiveapplicationofcarboncapture.TheCO2intheatmosphereismuchmoredilutethanin,forexample,fluegasfromapowerstationoracementplant.ThiscontributestoDAC’shigherenergyneedsandcostsrelativetotheseapplications.ButDACalsoplaysadifferentroleinnetzeropathways,includingasaCDRsolution.FuturecapturecostestimatesforDACarewide-ranginganduncertain,reflectingtheearlystageoftechnologydevelopment,butareestimatedatbetweenUSD125andUSD335pertonneofCO2foralarge-scaleplantbuilttoday.Withdeploymentandinnovation,capturecostscouldfalltounderUSD100/tCO2.DACcostsaredependentonthecapturetechnology(solid-orliquid-basedtechnologies),energycosts(priceofheatandelectricity),specificplantconfigurationandfinancialassumptions.Inlocationswithhighrenewableenergypotentialandusingbestavailabletechnologiesforelectricityandheatgeneration,DACcostscouldfallbelowUSD100/tCO2by2030.TheMiddleEastandthePeople’sRepublicofChina(hereafter“China”)couldbeamongtheleast-costlocationsforDACdeployment,togetherwithEurope,NorthAfricaandtheUnitedStates.However,thepotentialforcoststofalltotheselevelswillbestronglydependentonincreasedpublicandprivatesupportforinnovationanddeployment.DirectAirCaptureExecutivesummaryAkeytechnologyfornetzeroPAGE10IEA.Allrightsreserved.MapofrenewableenergysourcepotentialandCO2geologicalstorageIEA.Allrightsreserved.Notes:Thismapiswithoutprejudicetothestatusoforsovereigntyoveranyterritory,tothedelimitationofinternationalfrontiersandboundariesandtothenameofanyterritory,cityorarea.Sources:IEAanalysisbasedonrenewable.ninjaforhourlysolardataforutility-scalesolarPV;Copernicusforhourlywindspeeddatal.InnovationisneededacrossthedirectaircapturevaluechainDACtechnologiesrequiresignificantamountsofenergy.ThetwoleadingDACtechnologies–solidDAC(S-DAC)andliquidDAC(L-DAC)–wereinitiallydesignedtooperateusingbothheatandelectricity.ThelowertemperatureheatneedsofS-DACmeanitcanbefuelledbyrenewableenergysources(includingheatpumpsandgeothermal).ThehightemperatureheatneedsofL-DAC(upto900°C)underpincurrentplantdesignsthatrelyonnaturalgasforheat,althoughtheCO2fromtheuseofthisgasisinherentlycapturedwithintheprocessandnotemitted.Innovationtosupportrenewableenergyoptionsforhigh-temperatureindustrialheatwouldmaximisethecarbonremovalpotentialofL-DACplants.DACstillneedstobedemonstratedindifferentconditions.AmajoradvantageofDACisitsflexibilityinsiting:intheory,aDACplantcanbesituatedinanylocationthathaslow-carbonenergyandaCO2storageresourceorCO2useopportunity.ItcanalsobelocatednearexistingorplannedCO2transportandstorageinfrastructure.Yettheremaybelimitstothissitingflexibility.Todate,DACplantshavebeensuccessfullyoperatedinarangeofclimaticconditionsinEuropeDirectAirCaptureExecutivesummaryAkeytechnologyfornetzeroPAGE11IEA.Allrightsreserved.andNorthAmerica,butfurthertestingisstillneededinlocationscharacterised,forinstance,byextremelydryorhumidclimates,orpollutedair.InnovationinCO2useopportunities,includingsyntheticfuels,coulddrivedowncostsandprovideamarketforDAC.Earlycommercialeffortstodevelopsyntheticaviationfuelsusingair-capturedCO2andhydrogenhavestarted,reflectingtheimportantrolethatthesefuelscouldplay–alongsidebiofuels–inthesector.IntheNetZeroEmissionsby2050Scenario,aroundone-thirdofaviationfueldemandin2050ismetbythesesyntheticfuels,butcurrentlytheircostcanbemorethanfivetimesconventionalfossil-basedoptions.Furtherinnovationisneededtosupportcostreductionsandfastercommercialisation,andbuildapotentiallylargemarketforair-capturedCO2.RobustcertificationofdirectaircapturecansupportfutureinvestmentBusinessmodelsforDACarelinkedtohigh-qualitycarbonremovalservicesandCO2useopportunities.DACcompaniesareofferingcommercialCO2removalservicestoindividualsandcompanies.AlthoughDACwithCO2storageisamongthemostexpensiveoptionstobalanceemissions,itisattractinginterestfromcompaniesseekinghigh-qualityCDRthatoffersadditionality,durabilityandmeasurability.ThepurchaseofDAC-basedcarbonremovaliscurrentlylimitedtovoluntarycarbonmarkets.InternationallyagreedapproachestothecertificationandaccountingofDACareneeded.Thedevelopmentofagreedmethodologiesandaccountingframeworksbasedonlifecycleassessment(LCA)forDAC–alongsideotherCDRapproaches–willbeimportanttosupportitsinclusioninregulatedcarbonmarketsandnationalinventories.Notably,thelatestIPCCGuidelinesforNationalGreenhouseGasInventoriesdonotincludeanaccountingmethodologyforDAC,meaningthatCDRassociatedwithDACcannotbecountedtowardsmeetinginternationalmitigationtargetsundertheUnitedNationsFrameworkConventiononClimateChange(UNFCCC).Effortstodevelopcarbonremovalcertification,includingforDAC-basedCDR,havecommencedinEuropeandtheUnitedStates,aswellasthroughinitiativessuchastheMissionInnovationCDRMission.Theseeffortsshouldbeco-ordinatedwiththeaimofestablishinginternationallyconsistentapproaches.SixprioritiesfordirectaircapturedeploymentDACdeploymentmustbeacceleratedfornetzero.TheNetZeroScenariorequirestheimmediateandacceleratedscale-upofDAC,callingforanaverageof32large-scaleplants(1MtCO2/yeareach)tobebuilteachyearbetweennowand2050.Thiswillrequireincreasedpublicandprivatesupporttoreducecosts,DirectAirCaptureExecutivesummaryAkeytechnologyfornetzeroPAGE12IEA.Allrightsreserved.improvetechnologiesandbuildthemarketforDACtechnologies.TheIEAhasidentifiedsixnear-termprioritiesforDACdeploymentalignedwithnetzerogoals:1.DemonstrateDACatscaleasapriority.Targetedpoliciesandprogrammesareneededfornear-termdemonstrationanddeployment.GovernmentsshouldensurethatplannedprojectsareabletoprogresstooperationandprovideessentiallearningsforDACtechnologiesandsupplychains.2.FosterinnovationacrosstheDACvaluechain.Innovationwillbecriticalto:reducingmanufacturingandoperationalcosts,aswellastheenergyneedsforDACplants;supportingtheavailabilityoflow-emissionenergysourcesforhigh-temperatureheat;anddevelopingandreducingthecostofCO2useapplicationsincludingsyntheticaviationfuels.3.IdentifyanddevelopCO2storage.ThepotentialforDACtoremoveCO2fromtheatmosphereinlargequantitiesrestsonthedevelopmentofsuitablegeologicalCO2storage.Althoughthestoragepotentialisvast,thetimetodeveloptheseresourcescanbeaslongastenyearsandcouldactasabrakeonthescale-upofDACinsomeregions.4.DevelopinternationallyagreedapproachestoDACcertificationandaccounting.Robust,transparentandstandardisedinternationalcertificationandaccountingmethodologiesforDACareneededtofacilitateitsrecognitionincarbonmarketsandIPCCgreenhousegasinventoryreporting.5.AssesstheroleofDACandotherCDRapproachesinnetzerostrategies.ImprovedunderstandingandcommunicationoftheanticipatedroleofDACandotherCDRapproachesinnetzerostrategieswillhelpidentifythetechnology,policyandmarketneedswithincountriesandregions.Forexample,theUnitedKingdom’sNetZeroStrategyidentifiesaneedforaround80MtCO2oftechnology-basedcarbonremovalsby2050.6.Buildinternationalco-operationforaccelerateddeployment.CollaborationthroughinternationalorganisationsandinitiativessuchastheIEA,CleanEnergyMinisterial,MissionInnovation,andTechnologyCollaborationProgrammeonGreenhouseGasR&D(GHGTCP/IEAGHG)canplayanimportantroleinpromotingknowledgesharing,reducingduplicationinresearchefforts,andharmonisingapproachestoLCAandaccountingmethodologiesforDACtechnologies.DirectAirCaptureChapter1.GrowinginterestindirectaircapturefornetzeroAkeytechnologyfornetzeroPAGE13IEA.Allrightsreserved.Chapter1.GrowinginterestindirectaircapturefornetzeroIntroductionDirectaircapture(DAC)technologiescanplayanimportantroleinmeetingnetzerogoals.CapturingCO2directlyfromtheairandpermanentlystoringitremovestheCO2fromtheatmosphere,providingasolutionforlegacyemissionsaswellasawaytobalanceemissionsthataredifficulttoavoid.Air-capturedCO2canalsobeusedasaclimate-neutralfeedstocktoproducearangeofproducts,fromsyntheticaviationfuelstofoodandbeverages.ThenumberofDACinstallationshasbeengrowinginrecentyears,with18facilitiesnowoperatingaroundtheworld.Theseareallsmallscale:intotal,theyhavethecapacitytocapturealmost0.01MtCO2eachyear,butthefirstlarge-scaleDACplant(1MtCO2/year)isinadvanceddevelopmentandcouldbeoperatingintheUnitedStatesbythemid-2020s.AmajorboostinDACdeploymentthisdecadewillbeneededtomeetnetzerogoals.IntheIEANetZeroEmissionsby2050Scenario(NetZeroScenario),1DACdeploymentrapidlyscalesuptoreacharound85MtCO2in2030and980MtCO2in2050.ThepotentialforDACtocontributetoclimatechangemitigationisincreasinglybeingrecognised,withthetechnologybenefitingfromnewpublicandprivateinitiatives.In2021theUnitedStatescommittedUSD3.5billiontoestablishfourDAChubsandintroducedaDACPrizeprogrammeofferingUSD100millionforcommercial-scaleprojectsandUSD15millionforpre-commercialprojects.TheUnitedStatesalsoidentifiedDACasakeytechnologyforitsCarbonNegativeShot,announcedduringCOP26.TheUnitedKingdomhasearmarkedGBP100million(aroundUSD137million)forcarbondioxideremoval(CDR)approaches,includingDAC,whilefundingprogrammessupportingDACdevelopmentanddeploymenthavebeenestablishedinAustralia,Canada,Europeandelsewhere.1TheNetZeroScenarioisdesignedtoshowwhatisneededacrossdifferentsectorsbydifferentactors,andbywhen,fortheworldtoachievenetzeroenergysectorandindustrialprocessCO2emissionsby2050.ThescenarioaimstoensurethatCO2emissionsareinlinewiththeheadlinereductionsincludedbytheIPCCinitsSpecialReportonGlobalWarmingof1.5°C,andthattherearesubstantialreductionsinenergy‐relatedmethaneemissions.Inaddition,theNetZeroScenarioincorporatesconcreteactionontheotherenergy‐relatedSustainableDevelopmentGoalsrelatedtoachievinguniversalenergyaccessby2030andrealisingamajorreductioninairpollution.DirectAirCaptureChapter1.GrowinginterestindirectaircapturefornetzeroAkeytechnologyfornetzeroPAGE14IEA.Allrightsreserved.PrivateinvestorsarealsoincreasinglysupportingDAC.ItisoneoffourtechnologiesbeingtargetedforuptoUSD1.5billionininvestmentbyBreakthroughEnergyCatalyst,establishedbyBillGatesandacoalitionofprivateinvestors,anditisaneligibletechnologyfortheUSD100millionCarbonRemovalXPRIZE.CompaniesincludingMicrosoft,StripeandUnitedAirlinesareinvestinginDACfacilitiesandpurchasingDAC-basedcarbonremovaltosupporttheircorporateclimatetargets.ThisreportexploresthegrowingmomentumbehindDAC,togetherwiththeopportunitiesandchallengesforscalingupthedeploymentofDACtechnologiesconsistentwithnetzerogoals.Itconsidersthecurrentstatusofthesetechnologies,theirpotentialforcostreductions,theirfutureenergyneeds,andtheoptimallocationsforDACfacilities.Finally,thereportidentifiesthekeydriversforDACinvestmentandprioritiesforpolicyaction.TheroleofdirectaircaptureinmeetingnetzerogoalsDACcanplayanimportantroleinmeetingnetzerotargets,bothasakeyCDRapproachandasasourceofclimate-neutralCO2neededtoproducesyntheticfuelsandotherproductsthatrequireasourceofcarbon.2NetzerotargetsinherentlyrecognisethatsomeformofCDRwillberequired:“net”referstobalancinganyCO2thatisreleasedintotheatmospherefromhumanactivitywithanequivalentamountbeingremoved.ArangeoftechnologiesandapproachesareavailabletosupportCDR,includingnature-basedsolutions(afforestationandreforestation,forexample),enhancednaturalprocesses(suchasbiochar)andtechnology-basedapproachesunderpinnedbycarboncaptureandstorage(CCS)technologies.Theadvantagesandchallengesassociatedwithdirectaircaptureandstorage(DACS)withinthisportfolioarediscussedinChapter5.TheNetZeroScenariodoesnotrelyonnature-basedsolutions,butinsteadincorporatestechnology-basedCDRapproaches,namelyDACSandbioenergywithCCS(BECCS),tosteertheglobalenergysystemtonetzeroemissionsby2050.ThecontributionofDACSandBECCSevolvesovertheprojectionperiod,withalimitedbutstillambitiousroleforCDRto2030andsubstantialdeploymentbeyondthat.2TheCO2capturedfromtheatmospherecanbeconsideredaclimate-neutralfeedstockforCO2useapplicationsthatresultintheCO2beingre-releasedtotheatmosphere,includingsyntheticfuels.Howeverthisissubjecttothelifecycleemissionsfromthecaptureplant,includingtheenergyused.DirectAirCaptureChapter1.GrowinginterestindirectaircapturefornetzeroAkeytechnologyfornetzeroPAGE15IEA.Allrightsreserved.GlobalCO2capturefrombiomassandDACintheNetZeroScenarioIEA.Allrightsreserved.In2030almost90MtCO2/yeariscapturedviaDAC(fromaround7700tCO2/yeartoday),acceleratingsignificantlytoreach620MtCO2/yearin2040and980MtCO2/yearin2050.Cumulativelyaround12GtofCO2iscapturedviaDACbetween2020and2050,accountingfor11%ofthegrowthinallCO2captureoverthatperiod.In2050about13%ofallCO2emissionscapturedarefromDAC,64%ofwhicharestored,removingCO2fromtheatmospheretobalance(togetherwithBECCS)allremainingemissionsfromtransport,industryandbuildingssoastoachieveanetzeroemissionsenergysystem.Around350Mtor36%oftheCO2captureddirectlyfromtheairin2050isusedincombinationwithhydrogentoproducesynthetichydrocarbonfuels,notablyforuseinaviation,wheresyntheticfuelsmeetaroundathirdofaviationfueldemandthatyear.Usingair-capturedCO2enablesthesefuelstobeclimate-neutralovertheirlifecycle,recognisingthattheCO2willbere-releasedtotheatmosphereasthefueliscombusted.Inthisrespect,DACcontributestooneofveryfewsolutionsavailabletoreduceemissionsinaviationtransport,whichremainsoneofthemostchallengingenergysectorstodecarbonise.DirectAirCaptureChapter1.GrowinginterestindirectaircapturefornetzeroAkeytechnologyfornetzeroPAGE16IEA.Allrightsreserved.GlobalCO2capturefromDACSandDACwithuseintheNetZeroScenarioIEA.Allrightsreserved.Thescale-upofDACdeploymentintheNetZeroScenarioimpliesanaverageofmorethan30DACplantsof1Mt/yearbeingaddedeachyearduring2020-2050.Thisdeploymentwilldependonensuringcost-competitivenesswithothermitigationmeasuresaswellastheavailabilityoflow-carbonenergyandkeyconsumablessuchasCO2solvents.Capturingalmost1GtCO2fromtheairthroughDACin2050willrequirearound6EJoflow-carbonenergy,witharound90%ofthislow-carbonenergyneedbeingforheat.ThesupplychainimplicationsofthisexpansionarediscussedinChapter3.Globalenergyconsumption(left)andCO2capture(right)fromDACintheNetZeroScenarioIEA.Allrightsreserved.Note:GlobalCO2capturefromDACbasedonthedeploymentofbothL-DACandS-DAC.DirectAirCaptureChapter1.GrowinginterestindirectaircapturefornetzeroAkeytechnologyfornetzeroPAGE17IEA.Allrightsreserved.CDRinIPCCandIEAscenariosBoththeIPCCFifthAssessmentReportandtheIPCCSpecialReportonGlobalWarmingof1.5°CrelyonCDRtechnologiestomeetclimatetargets(respectively2°Cand1.5°Cabovethepre-industrialglobalaveragetemperature).ThisreliancereflectsthemanyscenariosthatconstitutetheIPCCscenariodatabaseandwhichhighlightpotentialpathwaysforthedecarbonisationoftheenergysystem.ThefourrepresentativepathwaysreportedintheIPCCSpecialReportonGlobalWarmingof1.5°Callrelyonsomeformofremoval,theextentofwhichdependsontherateandscaleofemissionsreduction:fromP1(lowenergydemandpathways),whichachieves1.5°Conlybyusinglandusemanagementandafforestation,toP4(fossilfuelpathway),whichreliesheavilyonCDRexemplifiedbyBECCS.Outofthe90individualscenariosthathaveatleasta50%chanceoflimitingwarmingto1.5°Cin2100,only18havenetzeroenergysectorandindustrialprocessCO2emissionsin2050(thesamelevelofemissionsreductionastheNetZeroScenario).ThescenariosassessedbytheIPCChaveamedianofaround15GtCO2capturedusingcarboncapture,utilisationandstorage(CCUS)in2050,doublethelevelintheNetZeroScenario.Moreover,CO2emissionscapturedandstoredwithBECCSandDACSintheIPCCscenariosareintherangeof3.5-16GtCO2in2050,comparedwith1.9GtCO2intheNetZeroScenario.Comparisonofenergy-relatedCDRin2050undertheIPCCscenariosandtheNetZeroScenarioIEA.AllrightsreservedSource:IEA(2021),AcloserlookatthemodellingbehindourglobalRoadmaptoNetZeroEmissionsby2050.DirectAirCaptureChapter1.GrowinginterestindirectaircapturefornetzeroAkeytechnologyfornetzeroPAGE18IEA.Allrightsreserved.DeploymentofdirectaircapturetodayEighteenDACplantsarecurrentlyoperationalgloballyandarelocatedinCanada,EuropeandtheUnitedStates.MostoftheseplantsaresmallandsellthecapturedCO2foruse,includingforPower-to-X3(chemicalsandfuels),beveragecarbonationandingreenhouses.InIceland,Climeworks(S-DAC)andCarbfixarecapturingCO2fromtheatmosphereandblendingitwithCO2capturedfromgeothermalfluidsforinjectionandundergroundstorageinbasalticrockformations.Thisisthefirstoperatingapplicationofthistype,turningCO2intorockswithinacoupleofyearsthroughmineralisation.TheplantwasexpandedinOctober2021inordertocapture4000tCO2/year,making“Orca”theworld’slargestDACplantremovingCO2fromtheatmosphere.DACglobaloperatingcapacity,2010-2021IEA.Allrightsreserved.Thefirstlarge-scaleDACplantisnowbeingfinancedanddevelopedintheUnitedStatesby1PointFive(adevelopmentcompanyownedbyOxyLowCarbonVentures).Theplant,whichwilluseCarbonEngineering’sDACtechnology(L-DAC),willhavethecapacitytocaptureupto1MtCO2peryear4andcouldbecomeoperationalasearlyas2024.Aplantofthissizewouldbeeligibleforthe45Qtaxcredit(currentlyprovidingUSD35pertonneofCO2usedinenhancedoilrecoveryandUSD50pertonneforCO2storage).Moreover,itcouldalsobe3Power-to-Xreferstoasuiteoftechnologiesthatconvertelectricityintootherformsofenergy,suchasammonia,hydrogenandevenheat.4Theprojectwillbedevelopedinsteps,withthefirsttraincapturing500000tCO2/year.DirectAirCaptureChapter1.GrowinginterestindirectaircapturefornetzeroAkeytechnologyfornetzeroPAGE19IEA.Allrightsreserved.eligiblefortheCaliforniaLowCarbonFuelStandard(LCFS)credit,withthesecreditstradingatanaverageofaroundUSD200/tCO2in2020.DACplantsinoperationworldwideCompanyCountrySectorCO2storageoruseStart-upyearCO2capturecapacity(tCO2/year)GlobalThermostatUnitedStatesR&DNotknown2010500GlobalThermostatUnitedStatesR&DNotknown20131000ClimeworksGermanyCustomerR&DUse20151CarbonEngineeringCanadaPower-to-XUse2015Upto365ClimeworksSwitzerlandPower-to-XUse201650ClimeworksSwitzerlandGreenhousefertilisationUse2017900ClimeworksIcelandCO2removalStorage201750ClimeworksSwitzerlandBeveragecarbonationUse2018600ClimeworksSwitzerlandPower-to-XUse20183ClimeworksItalyPower-to-XUse2018150ClimeworksGermanyPower-to-XUse20193ClimeworksNetherlandsPower-to-XUse20193ClimeworksGermanyPower-to-XUse20193ClimeworksGermanyPower-to-XUse201950ClimeworksGermanyPower-to-XUse202050ClimeworksGermanyPower-to-XUse20203ClimeworksGermanyPower-to-XUse20203ClimeworksIcelandCO2removalStorage20214000CompaniesleadingthedevelopmentofDACtechnologiesCompaniesthatareleadingthecommercialisationofDACtechnologiesinclude:•ClimeworksAG,foundedinSwitzerlandin2009asaspin-offoftheresearchuniversityETHZurich.Thecompanyhastodatecommissioned15plantsworldwideandhasbeensupportedbybothpublic5andprivateinvestors(includingthelargestprivateinvestmenttodateinDAC),whilealsoacquiring5IncludingtheSwissConfederation,theEUFrameworkProgrammeHorizon2020andtheGermanFederalMinistryofEducationandResearch.DirectAirCaptureChapter1.GrowinginterestindirectaircapturefornetzeroAkeytechnologyfornetzeroPAGE20IEA.Allrightsreserved.thecompetingcompanyAntecyBVin2019.ActivecollaborationsincludeajointdevelopmentagreementwithSvanteInc.oncarboncaptureandparticipationwithintheNorske-FuelASconsortium(aimingtoconvertrenewableelectricityresourcesandcapturedCO2intorenewablesyntheticfuels).FurthercollaborationsincludeonewithCarbfixandNorthernLightstoexplorethepotentialforaDACandCO2removalproject,andanotherwith44.01totesttheirDACtechnologyinOman.•CarbonEngineeringLtd,foundedin2009inSquamish(BritishColumbia,Canada)fromacademicworkconductedoncarbonmanagementtechnologiesattheUniversityofCalgaryandCarnegieMellonUniversity.ThecompanyiscurrentlyprivatelyownedandisfundedbyinvestmentorcommitmentsfromprivateinvestorsandgovernmentagenciesinbothCanadaandtheUnitedStates.CarbonEngineeringhassofarcommissionedonepilotplant,andhasrecentlysignedalicensingagreementwith1Point5tofinanceanddeploytheworld’slargestDACfacility(whichshouldstartcapturingCO2fromtheatmosphereby2024).Ithasalsocommencedpre-FEED(front-endengineeringanddesign)withPaleBlueDotEnergy(aStoreggagroupcompany)onthedevelopmentofaDACfacilityinScotland,UnitedKingdom.CarbonEngineeringhasjuststartedengineeringonanair-to-fuelplantthatisduetobecomeoperationalinCanadain2026.•GlobalThermostat,foundedintheUnitedStatesin2010bytwoacademicsfromColumbiaUniversity.ThecompanyhassofarcommissionedtwoDACpilotplantsandiscollaboratingwithExxonMobiltoadvanceandscaleupitscapturetechnology.InApril2021GlobalThermostatsignedanagreementwithHIFtosupplyDACequipmenttotheHaruOnieFuelspilotplantinChile,whichwillutilisecapturedCO2blendedwithelectrolytichydrogentoproducesyntheticgasoline.Theplantisdesignedtocaptureupto250kgofCO2perhour,equivalenttoaround2000tCO2/year.OthersmallercompaniesdevelopingDACtechnologiesincludeHydrocell(capturingCO2andrecoveringheatfromexhaustair),Infinitree(providingCO2enrichmentsolutionsforenclosedagriculturalapplications),Skytree(focusingonairqualitymanagementforelectricvehicles),SoletairPower(combiningventilationwithCO2captureforbuildings),CarbonCapture(capturingCO2usingmolecularsieves)andHeirloom(proposingahybridDACapproachbasedoncarbonmineralisation).KawasakiHeavyIndustriesisalsodevelopinganovelDACtechnologybasedontheirexistingCCUStechnology,originallydevelopedforpowergenerationapplications.Finally,CarbonCollectLimitediscurrentlycommercialisingtheDACtechnologydevelopedattheCenterforNegativeCarbonEmissions(ArizonaStateUniversity)called“MechanicalTreesTM”andbasedonmoistureswingadsorption.DirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE21IEA.Allrightsreserved.Chapter2.TechnologiestocaptureCO2fromtheairTwotechnologyapproachesarecurrentlybeingusedtocaptureCO2fromtheair:solidandliquidDAC.SolidDACtechnologymakesuseofsolidsorbentfiltersthatchemicallybindwithCO2.Whenthefiltersareheated,6theyreleasetheconcentratedCO2,whichcanbecapturedforstorageoruse.Liquidsystemspassairthroughchemicalsolutions(e.g.ahydroxidesolution),whichremovestheCO2whilereturningtherestoftheairtotheenvironment.Emergingapproachesatprototypelevelincludeelectro-swingadsorptionandmembrane-basedseparation.SolidandliquiddirectaircaptureSolidDAC(S-DAC)isbasedonsolidadsorbentsoperatingthroughanadsorption/desorptioncyclingprocess.Whiletheadsorptiontakesplaceatambienttemperatureandpressure,thedesorptionhappensthroughatemperature–vacuumswingprocess,whereCO2isreleasedatlowpressure7andmediumtemperature(80-100°C).Asingleadsorption/desorptionunithasacapturecapacityofseveraltensoftonnesofCO2peryear(e.g.50tCO2/year)andcanbeusedtoextractwaterfromtheatmospherewherelocalconditionsallow(earlyprototypeswereabletoremovearound1tonneofwaterpertonneofCO2).8AnS-DACplantisdesignedtobemodularandcanincludeasmanyunitsasneeded.Forinstance,thelargestoperatingS-DACplantcurrentlycaptures4000tonnesofCO2ayear.LiquidDAC(L-DAC)isbasedontwoclosedchemicalloops.Thefirstlooptakesplaceinaunitcalledthecontactor,whichbringsatmosphericairintocontactwithanaqueousbasicsolution(suchaspotassiumhydroxide)capturingCO2.ThesecondloopreleasesthecapturedCO2fromthesolutioninaseriesofunitsoperatingathightemperature(between300°Cand900°C).Alarge-scaleL-DACplantcancapturearound1MtCO2/yearfromtheatmosphere.Watertop-upmayberequireddependingonlocalweatherconditions.Forinstance,around4.7tonnesofwaterpertonneofcapturedCO2wouldberequiredforthisplantconfigurationatambientconditionsof64%relativehumidityand20°C.6AlternativeS-DACapproachesrelyonmoistureorpressureswing-basedprocesses.7Lowerthanatmosphericpressure,thereforeundervacuum.8CO2capturecapacityandwaterremovalvaryonacase-by-casebasis,withthecapturecapacityhighlysensitivetoproprietarytechnology,andwaterremovaldependentonbothtechnologyandairhumidity.DirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE22IEA.Allrightsreserved.S-DAC(top)andL-DAC(bottom)configurationsIEA.Allrightsreserved.Sources:IEAanalysisbasedonCarbonEngineeringandClimeworks.S-DACandL-DAChavedistinctfeaturesthatmayofferparticularadvantagesdependingontheenvironmentinwhichtheyareoperating.BothhavepotentialtoremoveCO2fromtheatmosphere(whenthecapturedCO2ispermanentlystored)ortobeasourceofclimate-neutralCO2foruseinproducts.Neitheroptionrequiresvaluablearablelandthatwouldbesuitableforagriculture,andthereforetheydonotcompetewiththefoodorbioenergyindustryfortheuseofland.Theyoperateatdifferenttemperaturesandaresuitableforlarge-scaleoperations(L-DAC),orsmall-scalebutmodularandthereforescalableoperations(S-DAC).Theircapitalandoperatingcostsaredeterminedbythesizeoftheplant(withtotalcostsincreasingwithoverallsize)anditsenergyneeds,togetherwithitsoperationalrequirements.WhileL-DACcantheoreticallyoperatecontinuouslyatsteadystatewithoutinterruption(excludingregularmaintenance),S-DACreliesonbatchDirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE23IEA.Allrightsreserved.operation,whichnecessitateshavingmultipleunitsinparallel,withsomeinoperationactivelycapturingCO2andothersinregeneration,releasingthecapturedCO2fromthefilters.9DACoperationisalsoaffectedbyitswaterrequirement:whileS-DACcanproducewaterbyextractingitfromtheair,L-DACneedswaterforitscontinuousoperation.KeyfeaturesofS-DACandL-DACtechnologyapproachesS-DACL-DACCO2separationSolidadsorbentLiquidsorbentSpecificenergyconsumption(GJ/tCO2)7.2-9.55.5-8.8Shareasheatconsumption(%)75-80%80-100%Shareaselectricityconsumption(%)20-25%0-20%Regenerationtemperature80-100°CAround900°CRegenerationpressureVacuumAmbientCapturecapacityModular(e.g.50tCO2/yearperunit)Large-scale(e.g.0.5-1MtCO2/year)Netwaterrequirement(tH2O/tCO2)-2tonone0-50Landrequirement(km2/MtCO2)1.2-1.70.4Lifecycleemissions(tCO2emitted/tCO2captured)0.03-0.910.1-0.4Levelisedcostofcapture(USD/tCO2)Upto540Upto3409Continuousoperationalsodependsontheenergysource,withenergystoragebecomingarequirementtoguaranteereliablesupplyifpoweredbyvariablerenewableenergy.DirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE24IEA.Allrightsreserved.S-DACL-DACMainadvantages•Possiblenetwaterproduction•Lesscapital-intensive•Modular•Operationcanrelyonlow-carbonenergyonly•Novelandthereforemorelikelytoseecostreduction•Lessenergy-intensive•Large-scalecapture•Operationreliesoncommercialsolvents•TechnologyadaptedfromexistingcommercialunitsMaintrade-offs•Moreenergy-intensive•Manualmaintenancerequiredforadsorbentreplacement•Morecapital-intensive•Reliesonnaturalgascombustionforsolventregeneration(withpotentialforfullelectrificationinthefuture)Notes:Landrequirementexcludeslanduseassociatedwithelectricityandheatgeneration.Lifecycleemissionsdonottakeintoaccountupstreamemissions.Pleasenotethatthecarbonintensityoftheelectricitysuppliedviathegridvariessubstantiallybyjurisdiction.Netwaterrequirementsaffectedbyregionalfactorssuchasairtemperatureandhumidity,withS-DACtechnologypotentiallybettersuitedtodryclimatesandL-DACtechnologytohumidclimates.Sources:Madhu(2021),Understandingenvironmentaltrade-offsandresourcedemandofdirectaircapturetechnologiesthroughcomparativelife-cycleassessment;Climeworks(2021),Directaircaptureandstorageandcarbondioxideremoval;Keithetal.(2018),AProcessforCapturingCO2fromtheAtmosphere;McQueenetal.(2021),Areviewofdirectaircapture(DAC):scalingupcommercialtechnologiesandinnovatingforthefuture;Fasihietal.(2019),Techno-economicassessmentofCO2directaircaptureplants;Beuttleretal.(2019),TheRoleofDirectAirCaptureinMitigationofAnthropogenicGreenhouseGasEmissions;WRI(2021),DirectAirCapture:ResourceConsiderationsandCostsforCarbonRemoval;IEAGHG(2021),IEAGreenhouseGasR&DProgramme.EmergingdirectaircapturetechnologiesEmergingDACtechnologies(atatechnologyreadinesslevel[TRL]below6)includeelectro-swingadsorption(ESA)andmembrane-basedDAC(m-DAC).ESAisbasedonanelectrochemicalcellwhereasolidelectrodeadsorbsCO2whennegativelychargedandreleasesitwhenapositivechargeisapplied(swingingthereforetheelectriccharge,ratherthantheoperatingtemperatureorpressureashappensinotherphysicalseparationtechniques).ThisapproachhasthepotentialtoseparateCO2frombothhighlyconcentratedsourcesandfromtheair,requirelimitedspaceasthecellsaretheoreticallystackable,andoperatewithoutadditionalequipmentforconditioningorpumping,unlikeL-DAC.TheESAseparationprocessdevelopedfirstattheMassachusettsInstituteofTechnologyandnowatVerdoxhasbeentestedatlabscale(TRL4)forCO2concentrationsfrom10%(e.g.powerplantexhaust)downto0.6%(e.g.ambientindoorair)withanefficiencyofaround90%.Inordertoreachcommercialapplication,furtherunderstandingofperformance,costs,materials,operationandmaintenanceisneeded.Moreover,thisESAtechnologyisnotyetsuitableforCO2DirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE25IEA.Allrightsreserved.removalfromatmosphericairasitisnottechnicallyabletoseparateCO2atsuchalowconcentration.Atthesametime,thecompanyisnotexcludingthisapplication,whichwouldrequireimprovedcapacityandkineticsduetothelowerinitialconcentrationofCO2inatmosphericair.OthercompaniesfocusingonelectrochemicalseparationmethodsforDACincludeMissionZeroTechnologies(aspin-outofDeepScienceVenture)andHolyGrail(whichrecentlyraisedUSD2.7millioninseedfundingtodevelopitstechnology).m-DAChasbeenproposedasanotherfeasibleoptionforcapturingCO2fromtheair;however,itisstillinitsinfancyandmajorchallengesareyettobeovercome.Generallyspeaking,membrane-basedapproachesaretechnicallychallengedbythelowconcentrationofCO2intheair,andshowlowCO2selectivityatambientpressure,requiringtheexpensivecompressionofaverylargeamountofambientairtoseparateCO2efficiently.Intheliteratureithasalsobeenarguedthatbettergaspermeance(i.e.theratiobetweenthegaspermeabilityofthemembraneanditsthickness)couldplayalargerrolethanCO2selectivityinmembranecostreduction.Iftrue,polymericmaterialswithhighCO2permeancecouldrepresentasuitableoptionforDAC.InmoretraditionalCCUSapplications,membrane-basedseparationtechnologiesarecurrentlyatTRL4forthecementindustryandatTRL6fornaturalgasprocessing.10FundamentalresearchintoalternativeDACapproachesiscurrentlytakingplaceatanumberofinstitutes.Forinstance,theOakRidgeNationalLaboratoryisseparatingCO2fromtheairatlabscaleandregeneratingthesolventatrelativelymildtemperatures(15-120°C)(Brethoméetal.,2018)(Custelceanetal.,2021),whiletheCenterforNegativeCarbonEmissionsatArizonaStateUniversityisprototyping“mechanicaltrees”thatrelyonwindinsteadoffansforairrecirculation.TheTRLscaleOnewaytoassesswhereatechnologyisonitsjourneyfrominitialideatomarketistousetheTRLscale.OriginallydevelopedbytheNationalAeronauticsandSpaceAdministration(NASA)intheUnitedStatesinthe1970s,theTRLprovidesasnapshotintimeofthelevelofmaturityofagiventechnologywithinadefinedscale.Thescaleprovidesacommonframeworkthatcanbeappliedconsistentlytoanytechnology,toassessandcomparethematurityoftechnologiesacrosssectors.10TRL9forcommercialseparationofCO2fornaturalgasprocessing.DirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE26IEA.Allrightsreserved.Thetechnologyjourneybeginsfromthepointatwhichitsbasicprinciplesaredefined(TRL1).Astheconceptandareaofapplicationdevelop,thetechnologymovesintoTRL2,reachingTRL3whenanexperimenthasbeencarriedoutthatprovestheconcept.Thetechnologynowentersthephasewheretheconceptitselfneedstobevalidated,startingfromaprototypedevelopedinalaboratoryenvironment(TRL4),followedbytestingofcomponentsintheconditionsitwillbedeployed(TRL5),throughtotestingthefullprototypeintheconditionsinwhichitwillbedeployed(TRL6).Thetechnologythenmovestothedemonstrationphase,whereitistestedinreal-worldenvironments(TRL7),eventuallyreachingafirst-of-a-kindcommercialdemonstration(TRL8)onitswaytowardsfullcommercialoperationintherelevantenvironment(TRL9).Arrivingatastagewhereatechnologycanbeconsideredcommerciallyavailable(TRL9)isnotsufficienttodescribeitsreadinesstomeetenergypolicyobjectives,forwhichscaleisoftencrucial.BeyondtheTRL9stage,technologiesneedtobefurtherdevelopedtobeintegratedwithinexistingsystemsorotherwiseevolvetobeabletoreachscale;othersupportingtechnologiesmayneedtobedeveloped,orsupplychainssetup,whichinturnmightrequirefurtherdevelopmentofthetechnologyitself.Forthisreason,theIEAhasextendedtheTRLscaleitusesinitsreportstoincorporatetwoadditionalreadinesslevels,whichfocusonmarket(ratherthantechnology)development:onewherethetechnologyiscommercialandcompetitive,butneedsfurtherinnovationforitsintegrationintoenergysystemsandvaluechainswhendeployedatscale(TRL10),andafinalonewherethetechnologyhasachievedpredictablegrowth(TRL11).MaturitycategoriesandTRLsalonginnovationcyclesIEA.AllrightsreservedINTEGRATIONNEEDEDATSCALESolutioniscommercialandcompetitivebutneedsfurtherintegrationefforts71INITIALIDEABasicprincipleshavebeendefined3CONCEPTNEEDSVALIDATIONSolutionneedstobeprototypedandapplied4EARLYPROTOTYPEPrototypeprovenintestconditions5LARGEPROTOTYPEComponentsproveninconditionstobedeployedPRE-COMMERCIALDEMONSTRATIONSolutionworkinginexpectedconditionsCOMMERCIALOPERATIONINRELEVANTENVIRONMENTSolutioniscommerciallyavailable,needsevolutionaryimprovementtostaycompetitiveFIRSTOFAKINDCOMMERCIALCommercialdemonstration,fullscaledeploymentinfinalform89102APPLICATIONFORMULATEDConceptandapplicationofsolutionhavebeenformulatedFULLPROTOTYPEATSCALEPrototypeprovenatscaleinconditionstobedeployed6PROOFOFSTABILITYREACHEDPredictablegrowth11SMALLPROTOTYPEorlabLARGEPROTOTYPEDEMONSTRATIONMATURELevelTECHNOLOGYDEVELOPMENTMARKETDEVELOPMENTCategorySub-categorySMALLPROTOTYPELARGEPROTOTYPEEARLYADOPTIONSTEADYSCALEUPCONCEPTDEMONSTRATIONMATUREMARKETUPTAKEDirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE27IEA.Allrightsreserved.CostofcapturingCO2directlyfromtheairCurrentcapturecostsviaDACarehighanduncertainCapturingCO2fromtheairismoreexpensivethancapturingitfromapointsource.ThisisbecausetheCO2intheatmosphereismuchmoredilutethan,forexample,inthefluegasofapowerstationoracementplant.11ThiscontributestothehigherenergyneedandcostofDACrelativetootherCO2capturetechnologiesandapplications.CO2capturecostatvaryingCO2concentrations,2020IEA.Allrightsreserved.Notes:Averagevaluesbyapplication.H2=hydrogen;SMR=steammethanereforming;NG=naturalgas;EO=ethyleneoxide.TheempiricaltrendlineshowsthecorrelationbetweencapturecostandCO2concentration.AsDACtechnologyhasyettobedemonstratedonalargescale(1MtCO2/yearandover),itscostsareextremelyuncertain.Capturecostestimatesreportedintheliteraturearewide,typicallyranginganywherefromUSD100/ttoUSD1000/t,whilecostestimatesfromthemaintechnologyprovidersvaryacrossUSD95-230/tCO2forL-DACandUSD100-600/tCO2forS-DAC(Keithetal.,2018;EuropeanCommissionJointResearchCentre,2019;CleanEnergySolutionsCenter,2020;TheCatalystGroup,2019).ArecentassessmentbyIEAGHGestimatesDACcostsforremovaltobeintherangeof11CO2concentration:inair=410ppm=0.041mol%;influegasfromnaturalgasbasedpowergeneration=4-8mol%;influegasfromcementproduction=14-33mol%.DirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE28IEA.Allrightsreserved.USD200-700/tCO2.12Forcontext,carbonremovalviaBECCScostsUSD15-80/tCO2,whileafforestation/reforestationcancostaslittleasUSD10/tCO2.Costsandenergyneedsvaryaccordingtothetypeoftechnology(solidorliquid),thesourceofenergy(fuel,electricity,orboth)andwhetherthecapturedCO2isgoingtobegeologicallystoredorusedimmediatelyatlowpressure.ForCO2storage,theCO2needstobecompressedataveryhighpressuretobeinjectedintogeologicalformations.Thisstepincreasesboththecapitalcostoftheplant(duetotherequirementforadditionalequipmentsuchasacompressor)andtheoperatingcosts(torunthecompressor).13Otherrelevantfactorsaffectingcapturecostsincludethescaleofdeployment,theplantloadfactorwhenDACispoweredbyvariablerenewableenergysources,andthecarbonintensityoftheenergysource.Thecarbonintensityoftheenergysourceisthemaindeterminantofthedifferencebetweenthecostofcaptureandthecostofremoval,withthelatterestimatedasthecostpertonneofCO2removedfromtheatmosphere.14Accordingtoourownestimates,thecostofcaptureviaDACforlarge-scaleapplications(1MtCO2/year)hasarangeofUSD125-335/tCO2,15dependingoncapturetechnology(solid-orliquid-basedtechnologies),energycosts(priceofheatandelectricity),financialassumptions,specificplantconfiguration,andwhetherthecapturedCO2isstoredorused.LowheatandelectricitypricescanlowerprojectedcostsofcaptureviaDACtojustabovetheindustrytargetofUSD100/tCO2.Ifcapturedemissionsweretobemonetisedusingsomeformofcarbonpricingscheme,thelevelisedcostofcaptureforDACcouldfallwellbelowUSD100/tCO2.Moreover,acarbonpriceabovearoundUSD160/tCO2couldmakeDAC-basedcaptureprofitable.12TheIEAGHGstudyreportsthenetlevelisedcostofDACS,takingintoaccountcarbonremovalaswellaslifecycleemissions,andincludesCO2transportandstoragecosts(notjustcapture).13Alongsidegeologicalsequestrationthroughinjection,CO2mineralisationisemergingasanalternativeforlong-termundergroundCO2storage,withthepotentialtolowertheenergydemandforCO2compressionbyupto30%comparedtotraditionalinjection.14QuantifiedasCO2captureddirectlyfromtheatmosphereminusCO2re-emittedonanLCAbasis(pleaserefertothesection“Carbonfootprintandcostofcarbonremoval”forfurtherdetails).15Referenceyear=2020;referencelocation=UnitedStatesofAmerica.Directheatassumedtobegeneratedbymeansofnaturalgascombustion.Electricityprice=USD21/GJ(USD75.6/MWh);naturalgasprice=USD2/GJ(USD2.1/MBtu).NopriceonCO2isimposed.CO2compressioncostincluded;transportandstoragecostsnotincluded.CAPEXcomprisesprocessequipment,butexcludesengineering,procurementandconstructioncosts.Forallequipment,discountrate=8%;lifetime=25years;capacityfactor=90%.DirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE29IEA.Allrightsreserved.Levelisedcostofcaptureatvaryingheat,electricityandCO2prices,DACS(upper)andDACwithCO2use(lower),2020IEA.Allrightsreserved.Notes:Directheatpricebasedonnaturalgascombustion.Forleftandrightgraphs:electricitycost=USD47/GJ(USD169/MWh)forhighandUSD10/GJ(USD36/MWh)forlow.Formiddleandrightgraphs:naturalgascost=USD9/GJ(USD9.5/MBtu)forhighandUSD1/GJ(USD1.1/MBtu)forlow.Forleftandmiddlegraphs,nopriceonCO2isimposed.CO2compressioncostforstorageincludedforDACSonly(uppergraphs),transportandstoragecostsnotincluded.CAPEXcomprisesprocessequipment,butexcludesengineering,procurementandconstructioncosts.Forallequipment,discountrate=8%;lifetime=25years;capacityfactor=90%.Referencecapturecapacityscale=1MtCO2/year.Regularmaintenance,whichisneededtomaintainasatisfactorylevelofperformanceoftheDACplant,includessorbentreplacement,whichiscurrentlyperformedmanually.ThisoperationisparticularlyburdensomeforS-DACduetothelayoutofthesystem.DACsorbentreplacementrates(0.25-38kg/tCO2)affectoperatingcosts,whichcouldincreaseevenfurtherifmorefrequentreplacementisneededduetosite-specificconditionssuchasairhumidityorpollution.DirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE30IEA.Allrightsreserved.ContributiontolevelisedcostofDACbytypeofexpenditure,2020IEA.Allrightsreserved.ThepotentialforreductionsinthecostofdirectaircaptureisconsiderableDACisanemergingtechnologycurrentlyatthedemonstrationstage(TRL6)and,assuch,hasconsiderablepotentialforperformanceimprovementandcostreduction.ResearchhasestimatedthatmassiveDACdeploymentasapolicyresponsetotheclimatecrisiscouldsubstantiallydecreaseitslevelisedcostofcapture.TheindustrytargetappearstobeUSD100/tCO2,asitwouldmakeDACcompetitivewithmitigationoptionsforcertainindustrialandtransportsectors.TheUSDepartmentofEnergyhaschosenthistargetfortheCarbonNegativeShot,launchedinNovember2021andaimingtobringthecostofDACbelowUSD100/tCO2inadecade.CapturecostsbelowUSD200-250/tCO2couldalreadybecommerciallyattractiveintheUnitedStateswherefacilitiesareabletoaccesstheCaliforniaLCFScredits(aroundUSD200/tCO2)togetherwithtaxcreditssuchasthe45Q(USD50/tCO2).Accordingtothemaintechnologyproviders,capturecostsareexpectedtodecreasesubstantiallyinthenextfivetotenyears,underpinnedbyamajorincreaseinDACdeploymentworldwide,fromthethousand-tonnescaletothemillion-tonnescale.Theanticipatedfallincostfromthefirstlargeprototype(firstofakind[FOAK])tothenthofakind(NOAK)planthasbeenattributedtospecificcomponentsaswellasimprovedconstructabilityandwell-establishedsupplychains.ForL-DACtheexpectedcostreductionfromFOAKtoNOAKis27%,ofwhich42%comesfromasinglekeyequipment:theaircontactor.Whilethisunitisbasedoncommercialcooling-towertechnology,itsexpectedcostreductioncomesfromanumberofmodificationstothestandardcommercialdesign,includingpackinggeometry(allowingforcrossflowexchangebetweensolventandair)anddepth(reducingpressuredropandincreasingpackingwettingandDirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE31IEA.Allrightsreserved.thereforeperformance).ForS-DAC,technologyprovidersareexpectingathreefoldtosixfoldcostreductionintheshorttomediumterm.ContributiontodeclineincostofDACbyhigh-leveldriverIEA.Allrightsreserved.Note:LCC=averagelevelisedcostofcapture;FOAK=firstofakind;NOAK=nthofakind;R&D=researchanddevelopment,representinglearningbyresearching;LBD=learningbydoing;EOS=economiesofscale.The“low”levelisedcostofcapturerepresentstheaveragecostforL-DACwhilethe“high”levelisedcostofcapturerepresentstheaveragecostforS-DAC.Referencecapturecapacityscale=1MtCO2/year.Pleasenotethatcostreductionsbasedonlearningbyresearching,learningbydoingandeconomiesofscalearenotfullyindependentandthereforecumulative;however,theyhavebeenrepresentedhereassuchforsimplicity.PerformanceimprovementisexpectedtocomemainlyfrominnovativesolventsabletoreduceDAC-specificenergyconsumption(“learningbyresearching”)andfromtechnologyspilloversfromothersectorsandapplications.Furthercostreductioncanbedrivenbydeployment(“learningbydoing”)andeconomiesofscale:Learningbyresearching:muchDACresearchfocusesonreducingtheenergyconsumptionneededtoseparateCO2atlowconcentrationsfromatmosphericair.ComparedtoestablishedtechnologiessuchasS-DACandL-DAC,emergingseparationtechnologiescouldrequireupto90%lessenergypertonneofCO2.Thishugepotentialcomesfrominnovativeapproachestoregeneratingthesolventatlowtomediumtemperatures,orbydifferentCO2separationtechniques(e.g.membrane-basedseparation).Learningbydoing:technologydeploymentdrivescostsdownasexperienceindesigning,producing,commissioningandoperatingDACplantsaccumulatesalongalearningcurve.Withintheenergysystem,learningrates(quantifyingthesteepnessofthelearningcurve:thehigherthelearningrate,thesteeperthelearningcurve,thefasterthecostdecrease)haverangedbetween10-15%onaverage,withexceptionallyrapiddropsforspecific,verysuccessfultechnologiessuchassolarPV(around20%).ForDACtechnologies,L-DAChasbeenDirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE32IEA.Allrightsreserved.comparedintheliteraturetomoretraditionalamine-based,point-capturetechnologies(whicharecurrentlyalreadycommercial)andarethereforeexpectedtohavea10%learningrate,whileS-DACisexpectedtohavehigherlearningrate(around15%)duetoitsmodularnature.PotentialforreductioninCAPEXofDACduetolearningbydoingIEA.Allrightsreserved.Notes:InitialaverageCAPEXpertonneofCO2capturecapacityindexedto1;referencecapturecapacityscale=1MtCO2/year;minimumdeploymentforlearning=1MtCO2/year;learningrate=10-20%;rateofdeploymentbasedonNetZeroScenario.Economiesofscale:theserepresentcostadvantagesrelatedtoeithermassproductionofacertainpieceofequipmentortheproductionofthesameequipmentatalargerscalecomparedtoitsinitialdesign.Massproductionallowsforsharedinfrastructureandfacilitiesandreliesonanoptimisedsupplychain.Economiesofscalebenefitsmall,modularunitsthatcanbemassproduced(suchasS-DACmodules),andalsolargeequipment(suchasthoserequiredforL-DAC)whosecostbecomescheaperperunitofoutputthanthesameequipmentonasmallerscale.Modularsystemsundergoingmassproduction,suchashouseholdappliances,havehistoricallyseenasteepdecreaseinprice.Asanexample,thepriceofair-conditioningunitsdecreasedby21%betweentheearly1990sandearly2010s,whiletheirenergyefficiencyperformanceincreased.Theyhavemultiplesimilaritieswithsolid-DACduetothepresenceofarotatingelement(i.e.afan),coolinganddryingloops,andclosedandopencircuits.Forlarge-scaleunits,the“ruleof6/10”givessatisfactoryresults(i.e.withina20%marginoferror).Itestimatesacostreductionproportionaltosixtenthsoftheratiobetweenthesizeofalarge-scaleunitandasmall-scaleunit.ForL-DAC,thiswouldmeanacostreductionofmorethan50%pertonneofCO2capturedwhenscalingupfrom(forexample)1Mtofcapturecapacityto5Mt.Technologyspillover:thistakesplacewhenatechnologydevelopedforaspecificsectororapplicationisunintentionallybeneficialtoanotherapplication.ExamplesDirectAirCaptureChapter2.TechnologiestocaptureCO2fromtheairAkeytechnologyfornetzeroPAGE33IEA.Allrightsreserved.oftechnologyspillovershavebeenseenbetweenbatteries,fuelcellsandelectrolysers,betweenlightweightwindturbines,roadvehiclesandaircraft,betweenairconditionersandheatpumps,andbetweenCCUSapplications.DACdevelopmenthasalreadybenefitedfromspilloversfrommoretraditionalamine-basedCCUS(forliquid-basedCO2separation),fromlowpressuredropconfigurationsdevelopedbytheautomotiveindustryforcatalyticconverters(forsolidadsorbents),andfromelectrochemistry(whichledtothedevelopmentofESA-DAC).Whiletechnologyspilloversaretypicallyunexpectedandthereforedifficulttopredict,performanceoptimisationofCO2separationsolventsinanyindustrialapplication(e.g.chemicalindustry,naturalgasrefining,aerospacetechnology)wouldgreatlybenefitDAC.Unfortunately,thereisnoconsensusonhowtoquantifytechnologyspillovers,duetothecomplexityoftheinteractionsamongdifferentsectors.DirectAirCaptureChapter3.KeyconsiderationsfordirectaircapturedeploymentAkeytechnologyfornetzeroPAGE34IEA.Allrightsreserved.Chapter3.KeyconsiderationsfordirectaircapturedeploymentScalingupdirectaircapturevaluechainsReachingthelevelofDACdeploymentenvisagedby2050intheNetZeroScenariowillbeasignificantbutnotinsurmountablechallenge,requiringonaverageeightlarge-scale(1MtCO2/year)DACplantstobebuilteachyearduringthecurrentdecade,50plantstobebuilteachyearduring2030-2040andalmost40plantsayeartobebuiltbetween2040and2050.16Buildingupamarketfromsuchasmallbasewillrequiretheexpansionofglobalsupplychainsforanumberofcommodities.Todeliver1GtofCO2removalviaDACwouldrequire17-36Mtofsteel,concrete,copperandaluminium(intotal)tobuildtheplants,aswellas3-7Mtofchemicalcommoditiesforliquidsolventsandsolidadsorbents.Thespecificdemandforsteelandcement(demandpertonneofCO2)forDACplantscoulddecreaseovertimeasaresultofprocessdesignintensification.ThisisparticularlytrueforS-DAC,wheretheprocesslayoutisbrandnewandnotbasedonexistingtechnology.17DACR&DeffortsarefocusingonCO2solventsandsorbents,withtheaimoffindinglessenergy-intensivealternatives.BasedonexistingcommercialDACtechnology,substantialdeploymentofL-DACcouldputpressureonthemarketforhydroxidesolutions,currentlysideproductsofchlorine,18whileaminesorbentsforS-DACarelikelytobeproducedfromammonia19andethyleneoxide.Capturingalmost1GtCO2/yearfromtheatmosphereby2050,inlinewiththeNetZeroScenario,couldrequireupto50Gtofwaterperyear(aroundathirdofLakeTahoe,UnitedStates)andaround6EJofenergyperyear.ThisisequivalenttoalltheenergyexportedbytheNetherlandsin2019.Iftheenergywassuppliedexclusivelyby,forexample,solarPV,theintegratedplant(includingDACplantandsolarPVfield)wouldrequireupto23000km2ofland(withmostofthelandneededforthepanels).ThisisequivalenttothesizeofSardinia.1632plantsayearonaverageduring2020-2050.17ClimeworksrecentlydevelopedslidingdoorstoisolateDACunitsactivelycapturingfromunitsinregeneration,substantiallydecreasingtheamountofsteelneededtobuildaplant.Source:https://climeworks.com/orca.18Averageenergyintensityofhydroxidesolutionsproduction=7-13.3GJ/t.19Averageenergyintensityofammoniaproduction=41GJ/t.DirectAirCaptureChapter3.KeyconsiderationsfordirectaircapturedeploymentAkeytechnologyfornetzeroPAGE35IEA.Allrightsreserved.DirectaircaptureenergyneedsTheenergyneedsofDACplantsarestronglyinfluencedbytheoperatingtemperatureofthetechnologies.WhilebothL-DACandS-DACwereinitiallydesignedtooperateusingheatandelectricity(withflexibleconfigurationsallowingforheat-onlyoperation),20theoptiontooperatethemusingonlyrenewableelectricitywouldbeveryattractivefromanenvironmentalperspective.However,forL-DACthiswouldrequirefurtherinnovationintheprovisionofhigh-temperatureheatfromelectricity.EnergyneedsofDACSandDACwithCO2usebytechnologyandCO2destinationIEA.Allrightsreserved.Basedonthecurrentcommercialtechnology,electricityisabletoprovideoperatingtemperaturesabovearound500°Conlyforveryspecificlarge-scaleapplicationswithintheironandsteelsector(e.g.smeltingreduction,electricarcfurnaces)andthealuminiumsector(e.g.Hall–Héroultprocess).Electricity-basedcalcinationisemerging,butcurrentlystillatTRL3,andmaythereforetakeawhiletobecomecommerciallyavailableforlarge-scaleoperation.Further,whilenumerousrenewabletechnologiescanprovidelow-temperatureheat(below150°C),feweroptionsaresuitableformedium-andhigh-temperatureprocesses.Therefore,whileS-DACcouldbepoweredbyavarietyofrenewableenergysources(e.g.heatpumps,geothermal,solarthermal,biomass-basedfuels),thecurrenthigh-temperatureneedsoftoday’sL-DACconfigurationdoesnotallowthatlevelofflexibilityandcouldatbestoperateusinglow-carbonfuelssuchasbiomethaneorrenewables-basedelectrolytichydrogen.Large-scaleL-DACplants20Relianceonfuelismoreeconomical,butsomeelectricityisrequiredtooperaterotatingequipment.DirectAirCaptureChapter3.KeyconsiderationsfordirectaircapturedeploymentAkeytechnologyfornetzeroPAGE36IEA.Allrightsreserved.havebeendesignedtousenaturalgasforheatandtoco-capturetheCO2producedduringcombustionofthegaswithouttheneedforadditionalcaptureequipment.ThisintegrationsubstantiallyreducestheL-DACplant’soverallemissionsandcanstillenablecarbonremoval.21However,anyfutureabilityofrenewableenergytosupplyhigh-temperatureheatcouldreducetheprocessemissionstonearzero,maximisingthepotentialforcarbonremovalandassociatedrevenuestreams.Acceleratingthecommercialavailabilityoflarge-scaleelectriccalcinationtechnologyisconsideredahighprioritytoenableL-DACplantstooperatepurelyonrenewableenergy.Operatingtemperatureforvariousheat-generatingtechnologiesIEA.Allrightsreserved.Notes:TheverticaldashedlinesindicatethemaximumoperatingtemperaturesforS-DACandL-DACrespectively.Sources:IEA(2019),Renewables2019.CarbonfootprintandcostofcarbonremovalReducingtheenvironmentalimpactofDACduringitsconstruction,commissioning,operationanddecommissioningisofparamountimportancetooptimisethevalueofthistechnologyasaclimatemitigationsolution.ThisiswhyitmakeslittlesensetopowerDACusinganythingotherthanlow-carbonenergysources.WhilenotallDACplantswillbefocusedoncarbonremoval(somemaysupplyCO2foruse),thepotentialforaDACplanttoeffectivelyremoveCO2isnotguaranteedandwilldependon1)whethertheCO2ispermanentlystored,and21Anyupstreammethaneemissionswouldalsoneedtobeminimised,inadditiontotheCO2capturefromthegascombustion,tosupportnegativelifecycleemissions.DirectAirCaptureChapter3.KeyconsiderationsfordirectaircapturedeploymentAkeytechnologyfornetzeroPAGE37IEA.Allrightsreserved.2)whethertheemissionsfromDACconstruction,commissioning,operationanddecommissioningarelowerthantheCO2emissionscapturedandremovedfromtheatmosphereoverthelifespanoftheplant.Lifecycleassessment(LCA)isneededtoquantifytheamountofcarbonremoved(ifany)byDACtechnologies.22LCAisacradle-to-graveorcradle-to-cradleanalysistechniquetoassessenvironmentalimpactsassociatedwith“allthestagesofaproduct’slife,whichisfromrawmaterialextractionthroughmaterialsprocessing,manufacture,distribution,anduse”.23Theresultdependsonanumberoffactors,whichinclude,forinstance,thechoiceofthereferencesystemanditsboundaries,thequantificationofchangesinlandmanagementanduse,andthetimingofemissionsandremovals.MostLCAstudiescurrentlyavailableonCDRtechnologiesfocusonBECCSorcarbonutilisationforbiocharproduction.OnlyalimitednumberofLCAsareavailableforDAC,withmoststudiesconcludingthatDACSiscarbonnegative,whileDACforCO2usecanbecarbonreducingwhenpoweredbylow-carbonenergysources.ForDACSconfigurationsrelyingonnaturalgasandelectricityfromthegrid,thecarbonremovalefficiency24hasbeenestimatedtobehigherthan60%,potentiallyuptoaround90%forconfigurationsco-capturingCO2emissionsfromnaturalgascombustionandunderoptimisticassumptions(e.g.longlifetime,lowspecificenergyconsumption).ForDACSconfigurationsrelyingonlow-carbonheatsources(suchaswasteheatandheatpumps),lifecycleemissionsstronglydependonthecarbonintensityoftheregionalelectricitygrid.Iflow-carbonoroff-grid(i.e.renewable)electricityisavailable,thecarbonremovalefficiencycanbeashighas97%.DACScarbonremovalefficienciesbyenergysourceSourceofheatSourceofelectricityCarbonremovalefficiencyDirectheat(naturalgas)Grid60-90%Heatpump(power-to-heat)SolarPV79-89%Heatpump(power-to-heat)Wind95%Heatpump(power-to-heat)Grid9-95%22LCAsonCDRtechnologiescannotonlyquantifytheircarbonfootprint,butcanalsoassessotheraspectssuchasfreshwaterecotoxicityandeutrophication,humantoxicity,metaldepletion,particulatematteremissions,photochemicalozoneformation,terrestrialacidificationandlandoccupation(Gibon[2017],Lifecycleassessmentdemonstratesenvironmentalco-benefitsandtrade-offsoflow-carbonelectricitysupplyoptions).23https://www.sciencedirect.com/topics/earth-and-planetary-sciences/life-cycle-assessment.24Thecarbonremovalefficiencyisdefinedhereastheshare(%)ofnetpermanentCO2removal(where“net”isthegrossminusindirectLCA-relatedemissions)oftheinitialgrossCO2removal(100%)bytheDACunit,inaccordancewithTerlouwetal.(2021).DirectAirCaptureChapter3.KeyconsiderationsfordirectaircapturedeploymentAkeytechnologyfornetzeroPAGE38IEA.Allrightsreserved.SourceofheatSourceofelectricityCarbonremovalefficiencyWasteheatSolarPV85-92%WasteheatWind96%WasteheatGrid48-97%Notes:Directheatassumedtobegeneratedbymeansofnaturalgascombustion.Carbonremovalefficiencydefinedasnetpermanentgreenhousegas(GHG)removalasashare(%)ofinitialgrossGHGremovalbytheDACunit.NetremovalcomprisesgrossGHGemissionsminusindirect(LCA-related)emissions.Notethatthecarbonintensityoftheelectricitysuppliedviathegridvariessubstantiallybyjurisdiction.Sources:Liu(2020),AlifecycleassessmentofgreenhousegasemissionsfromdirectaircaptureandFischer–Tropschfuelproduction;NETL(2021),LifeCycleGreenhouseGasAnalysisofDirectAirCaptureSystems;Terlouwetal.(2021),LifeCycleAssessmentofDirectAirCarbonCaptureandStoragewithLow-CarbonEnergySources;DeutzandBardow(2021),Life-cycleassessmentofanindustrialdirectaircaptureprocessbasedontemperature–vacuumswingadsorption;deJonge(2019),LifecyclecarbonefficiencyofDirectAirCapturesystemswithstronghydroxidesorbents;Keithetal.(2018),AProcessforCapturingCO2fromtheAtmosphere;Madhuetal.(2021),Understandingenvironmentaltrade-offsandresourcedemandofdirectaircapturetechnologiesthroughcomparativelife-cycleassessment.Carbonremovalcostsdecreasewithincreasingcarbonremovalefficiencies.Whentheelectricityisprovidedfromthegrid,itscarbonintensityhasthelargesteffectonthefinalcarbonremovalcost,especiallywhenitisusedtogenerateheatthroughpower-to-heattechnologiessuchasheatpumps,whosecoefficientofperformance(rangingacross2.4-5.8fortechnologiesatTRL6-11)dependsonthelocalclimate.ThebenefitsofreducingthecarbonintensityoftheenergyusedforDACSextendstodecarbonisingdistributedenergysourcesaswellascentralisedenergysources.DACScostofcarbonremovalbyenergysourceforheatandelectricity,2020IEA.Allrightsreserved.Notes:grid=electricitygrid;DH=directheat;HP=heatpump;WH=wasteheat.Averagecostofcaptureandcostofremovalbothincludeaveragetransportandstoragecosts(USD20/tCO2).Directheatassumedtobegeneratedbymeansofnaturalgascombustion.Referencecapturecapacityscale=1MtCO2/year.Sources:CarbonremovalefficienciesbasedonLiuetal.(2020);NETL(2021);Terlouwetal.(2021);DeutzandBardow(2021);deJongeetal.(2019);Keithetal.(2018).DirectAirCaptureChapter3.KeyconsiderationsfordirectaircapturedeploymentAkeytechnologyfornetzeroPAGE39IEA.Allrightsreserved.WaterandlandfootprintThewaterandlandfootprintsofDACplantsarerelativelylimitedcomparedtootherCDRapproaches;however,theycaninfluencethechoiceoftheDACtechnologyanditsenergysource.Basedontheinformationavailabletodate,L-DACrequireswaterforitsoperation(upto50tonnesofwaterpertonneofCO2capturedfromtheatmosphere),whileS-DACcanextractwaterfromtheair,alongsideCO2(0.8-2tonnesofwaterpertonneofCO2capturedfromtheatmosphere).ThewiderangesdependonDACtechnology,ambienttemperatureandhumidityandalsocapturesolutionconcentrationforL-DAC.IndryclimatesS-DACcouldprovidewater(foritsownuseor,forinstance,tofeedawaterelectrolysertoproducehydrogenandsubsequentlysyntheticfuelstogetherwiththecapturedCO2),whereasinextremelyhumidclimatesS-DACcouldstruggletokeepupwiththeamountofwatertoberemovedfromtheatmosphere.Waterremovalisinfactaside-effectofremovingCO2andaffectstheplant’sperformance,25althoughonlymarginally.Moreover,highlevelsofpollutioncanclogfiltersandthereforerequiremorefrequentmaintenance,increasingoperationalexpenditure.Incontrast,L-DACcouldaddstraintoanalreadystretchedwaterresource.Desalinisationandtransportofwatercouldbepossibleforplantslocatedneartheocean,butthiswouldslightlyincreasethecostofcapture(byaroundEUR3-8/tCO2,equivalenttoUSD3.5-9.5/tCO2).Therefore,L-DACwouldoperatebestinlocationswherewaterisnotscarce.ThelandfootprintofDACissmallerthanthelandfootprintofalternativeCDRapproaches,especiallythoserelyingonbiomass-basedremoval(suchasafforestation).Accordingtothelatestestimates,inordertocapture1MtCO2/yearfromtheatmosphereanL-DACplantwouldrequirearound0.4km2,andanS-DACplantintherangeof1.2-1.7km2(excludingprovisionofinputenergyneeds).Forcomparison,anemergingDACtechnologybasedonelectro-swingadsorption(ESA-DAC)hasthepotentialforanevensmallerlandfootprint,aslittleas0.02km2/MtCO2.WhilethiswouldbeaclearadvantageofESA-DAC,itscurrentTRListoolowtobeabletoquantifyitspotentialwhendeployedonalargescale.ThechoiceofthesourceofenergycansubstantiallyincreasetheDAClandfootprint,fromanadditional1.5km2/MtCO2/yearforgeothermal(L-DAC,geothermalpowermeetingelectricitydemand,naturalgasfromthegridmeetingheatdemand)to23km2/MtCO2/yearforsolarPV(S-DAC).25AccordingtoClimeworks,localclimate,weatherconditionsandaltitudehave“acertaineffectonperformancecharacteristics”.DirectAirCaptureChapter3.KeyconsiderationsfordirectaircapturedeploymentAkeytechnologyfornetzeroPAGE40IEA.Allrightsreserved.PublicacceptanceofDACTodatetherehavebeenveryfewstudiesthatinvestigatethepublic’sperceptionofDACamongstotherCDRapproaches.TheClimateAssemblyintheUnitedKingdomformedacitizen’sassemblyin2020tolearnaboutclimatechangeandthedifferentapproachesthecountrycouldtaketocombatitfurther.Duringthisassembly,108citizenswerepresentedwithinformationaboutreducingcarbonemissions,includinggreenhousegasremovalstrategies.Theywerethenabletodiscusstheco-benefitsandpotentialconsequencesthattheythoughtcouldcomefromimplementingthesepracticestoassistintheUnitedKingdomreachingitsnetzerogoal.Whensurveyedaboutwhichofthesestrategiesshouldbeapartofthenetzeroportfolio,respondentsshowed:•Mostlyfavourableopinionstowardnature-basedcarbonremovalsolutions.•ConcernwiththenewnessofDACtechnology.•Someconcernwiththereliabilityofgeologicalstorage.Thisledsomerespondentstorecommendscalingupnature-basedsolutionstoday,andfurtheringR&DintoDACsoitcouldthenbeusedlater.InadditiontothestudyconductedbytheClimateAssembly,Coxetal.(2020)conductedanationalsurveytogatherinformationaboutthepublicperceptionofBECCS,DACandenhancedrockweatheringfromconstituentsintheUnitedKingdomandtheUnitedStates.Theauthorsfoundthatbeforeconductinginformativeworkshops,alowpercentageofrespondentshadpriorunderstandingofCDR.Ingeneral,respondentsdidnotbelievethatCDRmethodsdealwiththerootcauseofclimatechangeandfearedthatthesemeasurescouldencouragemitigationdeterrence.WhenrespondentswereaskedspecificallyaboutDAC,theirmainconcernswere:•FullyunderstandingtheideaofcapturingCO2fromtheambientair.•PracticalandsocietalconcernsofstoringCO2underground.•BeingabletosimultaneouslydecarboniseandgenerateenoughenergytomeettheenergyrequirementsofDACsystems.Fromthesefindings,Coxetal.suggestthatDACcouldfacefurtherpublicoppositionduetoalackofengagementandunderstandingfromthepublicorduetothetimingoftheproject.SomeparticipantswerescepticalofCDRoptionsbecausetheyseemedtotaketoolongtodeploy,notaddresstheurgencywithwhichclimatechangeneedstobedealt,andrequiresufficienttestingtoavoidadverseconsequences.Lastly,itwassuggestedthatparticipantswouldwanttoseeCDRapproachesbeingco-deployedwithemissionmitigationeffortstoavoidCDRbeingusedtojustifythecontinueduseoffossilfuelswhereotheroptionsmayexist.DirectAirCaptureChapter4.OptimallocationsfordirectaircaptureAkeytechnologyfornetzeroPAGE41IEA.Allrightsreserved.Chapter4.OptimallocationsfordirectaircaptureAmajoradvantageofDACisthataplantcanbelocatedvirtuallyanywhere,forexamplenearasuitablestoragesiteforcarbonremoval,oranindustrialfacilityseekingasupplyofatmospheric(ratherthanfossil)CO2feedstock,reducingtheneedforlong-distanceCO2transport.Moreover,thistechnologyrequireslimitedwaterandlandcomparedtootherCDRoptions,especiallythoserelyingonbiomass-basedremoval.However,thissitingflexibilitydoeshavelimitations.WhileDACplantshavebeensuccessfullyoperatedinawiderangeofclimaticconditionsacrossEuropeandinNorthAmerica,furthertestingwouldbeneededinlocationscharacterisedbyextremelydry,humidorpollutedclimates,forinstance.Additionally,thechoiceoflocationneedstotakeintoaccounttheenergysourcetoruntheplant,whichhasalargeinfluenceoncapturecostandwillultimatelydeterminehowcarbon-negativethesystemis.BothS-DACandL-DACtechnologiescouldbefuelledbyrenewableenergysources,whileS-DACcouldalsobepoweredbyrecoveringlow-gradewasteheat,whichwouldconsiderablyreducecapturecostsandlifecycleemissions.26CapturecostbylocationDAChasalreadybeendemonstratedinEuropeandNorthAmerica.Thesetworegionsarewell-suitedtohostfurtherDACfacilitiesasaresultofthisexperienceandalsoduetothepotentialforco-sitingwithexistingindustrialhubsaswellasexistingandplannedCO2transportandstorageinfrastructure.Otherregionsthatcanbecost-competitiveforDACdeploymentarethosecharacterisedbyveryhighrenewableenergypotential(e.g.NorthAfrica,theMiddleEast),lownaturalgasprices(e.g.theMiddleEast,RussiaFederation),and/orastronginterestinCO2useandthecarboncirculareconomy(e.g.Japan).Intheseregions,thecostofcaptureviaDACvariesaccordingtoCAPEXandenergyandCO2prices.AglobalDACdeploymentrateinlinewiththeNetZeroScenario(i.e.90MtCO2and980MtCO2capturedin2030and2050respectively)wouldmeanasubstantialdecreaseinCAPEX,upto49-65%lowerin2030and65-80%lowerin2050comparedto2020.Onaregionalscale,CAPEXisexpectedtobelowerinChina,theMiddleEast,RussiaFederationandNorthAfricathaninEuropeandtheUnitedStates,duetocheapermaterialsandmanufacturing.Regionscharacterisedbyabundantgasresources(suchasRussiaFederationandtheMiddleEast)areexpectedtohavelowergaspricesthanEuropeandtheUnitedStates,whileCO226Thiswould,however,limitthelocationflexibilityoftheplant.DirectAirCaptureChapter4.OptimallocationsfordirectaircaptureAkeytechnologyfornetzeroPAGE42IEA.Allrightsreserved.pricesareexpectedtobehigherinEurope,theUnitedStatesandJapan(uptoUSD250/tCO2)thanintheotherselectedregions.AllofthesefactorscontributetotheregionalcostofcarboncapturedviaDACdecreasingby31-43%during2020-2030andby10-24%during2030-2050.LevelisedcostofcapturingcarbonbyDACStechnologyforselectedregions,2030and2050WithoutacarbonpriceWithacarbonpriceIEA.Allrightsreserved.Notes:L=L-DACS;S=S-DACS.CAPEXlearningrate=10%forL-DAC,15%forS-DAC(duetohigherdegreeofmodularityforthelattertechnology),withDACdeploymentbasedonNetZeroScenario;heatassumedtobegeneratedbymeansofnaturalgascombustion(directheat)orbeprovidedasfreewasteheat,electricityprovidedbygrid,solarPV,onshoreoroffshorewindpowergeneration;regionalnaturalgaspricesandelectricitypricesconsistentwithNetZeroScenariofortheyears2030and2050:naturalgasprice=USD1-5/GJ;electricityprice=USD4-49/GJ;CO2price=USD130/tCO2in2030,USD250/tCO2in2050;emissionfactorforelectricityproduction=0,fornaturalgas=0.056tCO2/GJbasedonIPCCguidelinesforstationarycombustionaccordingtohttps://www.ipcc.ch/report/2019-refinement-to-the-2006-ipcc-guidelines-for-national-greenhouse-gas-inventories/.Referencecapturecapacityscale=1MtCO2/year.DirectAirCaptureChapter4.OptimallocationsfordirectaircaptureAkeytechnologyfornetzeroPAGE43IEA.Allrightsreserved.Withoutacarbonpriceinplace,alltheselectedregionshavethepotentialtocaptureCO2directlyfromtheairforlessthanUSD100/tCO2,withtheMiddleEastreachingcapturecostsforDACbelowUSD50/tCO2thankstoacombinationofallthefactorsmentionedabove(lowCAPEX,lownaturalgaspriceandlowelectricityprice).HighrenewableenergypotentialcoupledwithbestavailabletechnologiesforelectricityandheatgenerationcansubstantiallydecreasethecapturecostofDAC.AcarbonpriceofUSD250/tCO2in2050allowsDACtobecomeprofitableinallregionswhenpoweredbyheatandrenewableelectricity,fromeithersolarPV,oronshoreandoffshorewind.Levelisedcostofcapturingcarbon(includingUSD250/tcarbonprice)byDACStechnologyandenergysourceforselectedregions,2050IEA.Allrightsreserved.Notes:Directheatassumedtobegeneratedbymeansofnaturalgascombustion.L=L-DACS;S=S-DACS.CAPEXlearningrate=10%forL-DAC,15%forS-DAC(duetohigherdegreeofmodularityforthelattertechnology),withDACdeploymentbasedonNetZeroScenario;heatprovidedbymeansofnaturalgascombustion,electricityprovidedbygrid,solarPV,onshoreoroffshorewindpowergeneration;regionalnaturalgaspricesandelectricitypricesconsistentwithNetZeroScenariofortheyear2050:naturalgasprice=USD1-5/GJ;electricityprice=USD4-44/GJ;CO2price=USD250/tCO2;emissionfactorforelectricityproduction=0,fornaturalgas=0.056tCO2/GJbasedonIPCCguidelinesforstationarycombustionaccordingtohttps://www.ipcc.ch/report/2019-refinement-to-the-2006-ipcc-guidelines-for-national-greenhouse-gas-inventories/.Referencecapturecapacityscale=1MtCO2/year.EU=EuropeanUnion;US=UnitedStates;NAFR=NorthAfrica;ME=MiddleEast;RUS=RussiaFederation;JPN=Japan.EnergysourcesLocationscharacterisedbyhighrenewablepotentialarebestplacedtohostDACplants,especiallyifalsocharacterisedbysubstantialCO2storagepotentialwherecarbonremovalistheobjective.Forexample,attheOrcaplantinIcelandgeothermalpowerisbeingusedtoproduceelectricityandtopowerS-DACforCO2captureandsubsequentstoragethroughmineralisation.ThesameDACtechnologywillsoonbetestedinOman,whichhaslargepotentialforsolarPVandabundantnaturalperidotiteformationsforCO2mineralisation.RenewableenergysourcessuchassolarandwindarecharacterisedbyacertainlevelofDirectAirCaptureChapter4.OptimallocationsfordirectaircaptureAkeytechnologyfornetzeroPAGE44IEA.Allrightsreserved.sitingflexibility;however,theygenerateelectricityandheatinadiscontinuousmanner,resultinginlowutilisationratesforaDACplantsolelyreliantonthem.PoweringDACexclusivelywithrenewableelectricitythatwouldotherwisebecurtailedwouldincreasethecostofcaptureevenfurther,duetolowutilisationrates.WhileenergystoragecouldensurethecontinuousoperationoftheDACplant,itwouldincreasethecapitalcostofthesystem.OtherrenewableenergysourcesthatcouldbeconsideredforpoweringDACincludegeothermalandhydropower(onlyavailableinveryspecificlocations),biomethane(requiringsubstantiallandandwater,andpotentiallycompetingwithfoodproductionaswellasotherusesforlimitedbioenergyresources)andconcentratedsolarpower(whichhasseenonlylimiteddeploymenttodate).Renewableheatandelectricityproductionopportunitiesvaryamongandwithinregions.Whenaregionischaracterisedbyhighrenewablepotential,theassessmentofitssuitabilityforsubstantialDACdeploymentshouldtakeintoaccountanumberofadditionalfactorsrelatedtolanduseandlandusechanges.Theseinclude,forinstance,thedegreeofurbanisationandthepresenceofnaturalhabitatsandecosystems,andmarineprotectedareas.AccordingtoarecentIEAanalysis,mostcoastalregionsarecharacterisedbyhighwindpotential,whichcanalsobefoundinthecentralUnitedStates,thesouthernregionofSouthAmerica,andintheUnitedKingdomandIreland.Thepotentialfromsolarpower(bothconcentratedsolarandPV)ismorespreadoutglobally,withhighpotentialinregionsacrossthesouthwesternUnitedStatesandMexico,easternSouthAmerica,theMiddleEastandeasternAustralia.DirectAirCaptureChapter4.OptimallocationsfordirectaircaptureAkeytechnologyfornetzeroPAGE45IEA.Allrightsreserved.MapofrenewableandnuclearenergysourcepotentialandCO2geologicalstorageIEA.Allrightsreserved.Note:Thismapiswithoutprejudicetothestatusoforsovereigntyoveranyterritory,tothedelimitationofinternationalfrontiersandboundariesandtothenameofanyterritory,cityorarea.OperatinghydroplantshavebeenomittedfromthemapastheirconnectiontoastandaloneDACplantwouldbetechnicallychallenging.Sources:IEAanalysisbasedonrenewable.ninjaforhourlysolardataforutility-scalesolarPV;Copernicusforhourlywindspeeddata;Pilorgé,H.etal.(2021),GlobalmappingofCDRopportunities,CDRPrimerfornuclear,hydroandgeothermal.Co-locatingDACfacilitieswithexistingassetsandinfrastructurewherewasteheatisavailablepresentsanotheroptiontopowerDACplants.Sourcesofwasteheatincludepowerandindustrialplants(suchaschemicalplants,pulpandpapermills,andsteelandglassmakingplants),combinedheatandpowerplants,syntheticfuelproductionprocesses,incinerationprocessesandcoolingtowers(atpowergenerationplants,e.g.nuclear,oronbuildings).In2020SouthernCompanyintheUnitedStatesannounceditsinterestintestingDACtechnologiesfortheirpotentialco-sitingwithexistingassetsattheNationalCarbonCaptureCenter.EDFisactivelyseekingpartnersabletooperatehydrogenandDACplantsusingwasteheatrecoveredfromtheplannedSizewellCnuclearpowerplantintheUnitedKingdom.ADACplantbasedinHinwil(Switzerland),feedingCO2toalocalgreenhouse,iscurrentlypoweredmainlybywasteheatfromanearbywasterecoveryfacility,whileanotherinApulia(Italy)reliesonwasteheatfromthecoolingcircuitsofamethanationreactorproducingtransportfuelfromhydrogenandair-capturedCO2.OthersourcesofenergythatcouldbeusedtopowerDACincludenuclear,geothermalandhydropowerplants.MostgeothermalplantsarelocatedalongthewestcoastoftheUnitedStatesandMexico,andinJapanandthePhilippines,whilemanyhydropowerplantsarelocatedacrossSouthAmerica,EasternDirectAirCaptureChapter4.OptimallocationsfordirectaircaptureAkeytechnologyfornetzeroPAGE46IEA.Allrightsreserved.Europe/EurasiaandsouthernChina.NuclearplantsaremainlylocatedintheeasternUnitedStates,Europe(especiallyinFrance),alongtheeastcoastofChinaandinJapan(whereanumberofreactorsarebeingdecommissioned).Co-locationisimportantnotonlyforaccesstoalreadyavailablelow-carbonenergysources,butalsoforCO2infrastructure.Air-capturedCO2canbetransportedalongsideCO2capturedfrommoreconcentratedsources(e.g.powerandindustrialplants)tofacilitiesthatuseit,ortogeologicalstoragesites.ThelatterconfigurationwouldallowCO2removalaswellasCO2abatement(fromconcentratedsources).AnextensivenetworkofCO2infrastructureisalreadypresentincountriessuchastheUnitedStates,whilepartoftheoilandgasinfrastructurecouldberepurposedinregionssuchasEuropetotransportCO2.Useandstorageofair-capturedCO2OnceCO2hasbeencapturedfromtheatmosphere,itcanbestoredundergroundforpermanentremoval,oritcanbeuseddirectly(e.g.forbeveragecarbonation,ingreenhousesfertilisation,orasarefrigerant)orindirectly(e.g.asafeedstockforprocessesproducingchemicals,fuelsandbuildingmaterials).Outofthe18DACplantscurrentlyoperatingworldwide,onlytwoarestoringCO2inadedicatedstoragesite,whiletheremaining16arecapturingtheCO2foruseinnearbyindustrialfacilities.CarbonremovalrequirestheCO2tobepermanentlystored.Mostlarge-scaleCO2useapplications,includingsyntheticfuels,resultintheCO2ultimatelybeingre-releasedintotheatmosphere.27CO2usecanstilldeliverclearclimatebenefits,particularlywhentheapplicationisscalable,useslow-carbonenergyanddisplacesaproductwithhigherlifecycleemissions.Inthedecarbonisationpathtowardsnetzeroemissions,atmosphericCO2willeventuallyneedtodisplacetheuseoffossil-basedcarbon.WhileCO2usecandeliverclimatebenefitsunderthecircumstancesmentionedabove,itisacomplementratherthananalternativetoCO2storage,whichisexpectedtobedeployedatamuchlargerscaleinordertoreachinternationalclimategoals.IntheIEANetZeroEmissionsScenario,around95%oftotalcapturedCO2(acrossallCCUSapplications)isdestinedforCO2storageratherthanuse.Ofthe980MtCO2capturedviaDACin2050,630MtCO2ispermanentlystoredwhile350MtCO2isforCO2use(mainlyforaviationfuels).CO2capturedfromtheatmospherethroughDACcanbestoredgeologicallyindeepsalineaquifers(havingthelargeststoragecapacity),indepletedoilandgasfields,andalsoinotherrockformationssuchasbasalt.Thereissubstantial27Anotableexceptionincludeslow-carbonconcretewithCO2,whichrepresentsanexampleofCO2utilisationwithahighlevelofpermanence.DirectAirCaptureChapter4.OptimallocationsfordirectaircaptureAkeytechnologyfornetzeroPAGE47IEA.Allrightsreserved.experiencewithlarge-scalegeologicalstorageofCO2:theSleipnerCO2storageprojectstartedoperationsin1996,andwasfollowedbytheSnøhvitCO2storageproject(2008),theQuestproject(2015),theIllinoisindustrialproject(2017),QatarLNG(2019)andtheGorgonproject(2019).Thesesixprojectsarenowstoringalmost10MtCO2/yearindedicatedstoragesites.28Measuring,monitoringandverification(MMV)isneededtoensurethatCO2isinjectedandretainedwithinthestoragesite,andtomeasurethestoragerateandtotalstoredvolumewithinasite.TheoveralltechnicalcapacityforstoringCO2undergroundworldwideisunderstoodtobevast,butdetailedsitecharacterisationandassessmentarestillneededinmanyregions.Totalglobalstoragecapacityinsalineaquifersanddepletedoilandgasfieldshasbeenestimatedatbetween8000Gtand55000Gt.Theavailabilityofstoragediffersconsiderablyacrossregions,withRussiaFederation,NorthAmericaandAfricaholdingthelargestcapacities.SubstantialcapacityisalsothoughttoexistinAustralia.ThecostsandtimeneededtodevelopCO2storagefacilitieswillbelocation-specificandinfluencedbytheavailabilityofexistingsubsurfacedataandbyreservoirpropertiesandcharacteristics.CO2storagecostscanbequitelow;forexample,morethanhalfofonshorestorageintheUnitedStatesisestimatedtobeavailableatbelowUSD10/tCO2,whileabouthalfitsoffshorestorageisestimatedtobeavailableatcostsbelowUSD35/tCO2.ThesitingflexibilityofDACcouldenablefacilitiestobebuiltwherethelowest-costCO2storageresourcesareavailable.Thetimelinesassociatedwithdevelopingstorage–uptotenyearsfromprojectconceptiontoCO2injection–couldbecomeabottleneckforDACdeployment(andCCUSdeploymentingeneral)withoutacceleratedeffortstoidentifyanddevelopCO2storagesites.Asidentifiedabove,co-locatingDACfacilitieswhereCO2transportandstorageinfrastructureisalreadyavailableorplannedcanservetoreducecostsandsupportfasterprojectdeployment.MineralisationofCO2forpermanentstorageCO2canbestoredinrockformations(suchasbasaltsandperidotites)thathavehighconcentrationsofreactiveminerals.InjectedCO2becomestrappedwhenitreactswithmineralsintheformationtoformsolidcarbonateminerals.Whilethetheoreticalstoragecapacityofbasaltshasbeenestimatedtobeverylarge(100k-28Almost30commercialCCUSprojectsareoperatingaroundtheworld,withcapacitytocapturemorethan40MtCO2/year.Ofthis,around30MtCO2/yearisbeinginjectedintooilandgasreservoirsforenhancedoilrecovery.DirectAirCaptureChapter4.OptimallocationsfordirectaircaptureAkeytechnologyfornetzeroPAGE48IEA.Allrightsreserved.250kGtCO2),furthertestingandresearchisrequiredtodevelopthisstorageoption(currentlyatTRL4),notablytodeterminewaterrequirements,whichcanbeconsiderable.29Largebasaltformationsexistinseveralregionsaroundtheworld,includinginareaswheretheremaybelimitedconventionalstoragecapacity,suchasIndia.ThispotentiallyopensupnewopportunitiesforCCUS,particularlyasbothonshoreandoffshoreformationscouldbeconsideredforstorage.ThereareonlytwoDACplantscurrentlystoringCO2throughmineralisation,bothinIceland:theplantscaptureCO2fromtheairandblenditwithCO2capturedfromgeothermalfluidbeforeinjectingitintoundergroundbasaltformations,whereitismineralised,i.e.convertedintoamineral.AgaininIceland,CarbfixhasrecentlyannouncedtheintentiontobuildaCO2mineralstorageterminal,abletostoreCO2receivedfromanumberofcustomerslocatedinnorthernEurope.Thedevelopmentofthishubisinthreephases,startingin2025-2027withthemineralisationof300000tCO2ayear,upto3MtCO2/yearbythemid-2030s.Thestoragepotentialforair-capturedCO2inbasaltformationswillbesooninvestigatedinOmanaswell.TheprojectaimstoprovideinsightsforDACdeploymentintheMiddleEast,whichischaracterisedbyverydifferentclimaticconditionsthanotherregionswhereDACiscurrentlydeployed(namelyEuropeandNorthAmerica).29TheCO2canbedissolvedinwatertospeedupinsitucarbonisation.DirectAirCaptureChapter5.DirectaircaptureaspartofacarbondioxideremovalportfolioAkeytechnologyfornetzeroPAGE49IEA.Allrightsreserved.Chapter5.DirectaircaptureaspartofacarbondioxideremovalportfolioWhatiscarbondioxideremoval?CDR(carbondioxideremoval)isanumbrellatermthatreferstoapproachesthatdrawCO2fromtheatmosphere,directlyorindirectly,andpermanentlystoreit.DACSisoneofaportfolioofCDRapproaches,whichincludenature-basedsolutions,enhancednaturalprocessesandtechnology-basedsolutions.Removingcarbonfromtheatmospherewillplayanimportantroleinmeetingclimategoalsasitcan1)balanceorneutraliseemissionsinhard-to-abatesectorsthatareotherwisetechnicallydifficultortoocostlytoabatedirectly,and2)enable“netnegative”emissionsataglobalscale,removinghistoricalemissionsthathaveaccumulatedintheatmosphereandcompensatingfornear-term“overshoots”whereemissionreductionsarenotdeliveredfastenoughtomeet1.5°Cpathways.VirtuallyallclimatemodelsconsideredbytheIPCCthatseektolimitfuturetemperatureincreasesto1.5°CincludesignificantCDRdeployment,includingfornetnegativeemissionsinthesecondhalfofthecentury.TherateofCDRadoptionfrom2050onwardstronglydependsonwhathasbeenassumedforthefirsthalfofthecentury,withearlyinactionoremissionsovershootrequiringsteepadoptionafter2050.SomescenariosdemonstratethatthelimitedadoptionofCDRtechnologies(10GtCO2/yearmaximumby2050and20GtCO2/yearmaximumby2100)ornoadoptionatallmaybepossible.Butthesescenariosrequireanaggressivetechnologyreplacementstrategy,togetherwithstabilisationofboththeglobalpopulationandenergydemand(Grubleretal.,2018;vanVuurenetal.,2013;vanVuurenetal.,2018).DespitethehighrelianceonCDRinmanyclimatemodels,thereisconsiderableuncertaintyinthefuturescalabilityandclimateimpactoftheseapproaches.ScientificunderstandingdoesnotyetprovideconfidencethatwecanrelyonCDRatsomepointinthedistantfutureasaretroactivemeansofcounteractinganovershootoftheemissionstrajectoryrequiredtomeetclimategoals.AccordingtotheSixthAssessmentReportoftheIPCC,theresponseoftheclimatesystemtoCDRdeploymentisexpectedtobedelayedbyyearstocenturies,andsoistheresponseofthecarbonpool(accumulatedcarbonintheatmosphere)tonetnegativeemissions.DirectAirCaptureChapter5.DirectaircaptureaspartofacarbondioxideremovalportfolioAkeytechnologyfornetzeroPAGE50IEA.Allrightsreserved.ThisuncertaintysurroundingCDRapproaches,includingDACS,underscorestheimportanceoftheseapproachesbeingacomplementandnotanalternativetocuttingemissionsnow,oranexcusefordelayedaction.Whatarethemaincarbondioxideremovaloptions?Therangeofcarbonremovalapproachesincludesnature-basedandtechnology-basedoptions,andoptionsthatenhanceanaturallyoccurringprocess.TheyremoveCO2eitherdirectlyfromtheair(e.g.DAC)orindirectly(e.g.biomassgrowing)andstoretheCO2eithergeologically,withintheterrestrialbiosphere(withinsoils,mineralsorbiomass),orintheocean.Theseapproachesdifferintheircarbon,landandresourcefootprint,potentialscaleofdeployment,TRL,lifecycleemissionsandimpactonthebiosphere,costandperformance,supplychains,andconfigurationandmodularity.TogetherwithDACS,themostpromisingCDRoptionsincludeafforestationandreforestation(AR)andbioenergywithCCS(BECCS).Thisevaluationisbasedontheircurrentstatusandontheirtechno-economicpotentialforscalability.DACSandBECCShavebeenidentifiedbytheSixthAssessmentReportoftheIPCCastheCDRoptionswiththehigheststoragepermanence,whileARastheoptionwiththeloweststoragepermanence.WhileCDRoptionsrelyingonbiosphere-basedstorage(e.g.biomass,soilandocean)aregenerallycharacterisedbylowstoragepermanence,theystillrepresentalargeshareofwhatitiscurrentlyavailableontheCDRmarket.Forexample,in2020MicrosoftandStripecumulativelyreceived236proposalsforCDRsolutions,withmorethan95%ofthem(inCO2volumeterms)beingforlowpermanenceoptions(lessthan100years).Thesewerenotconsideredreliablebythecompaniesandwerenotselectedforinvestment.WhileDACS,BECCSandARarecurrentlyinoperation,otherCDRoptionsarestillintheR&Dphaseandfurtherstudiesareneededtobetterunderstandtheirpotentialroleandscalability,aswellastheirenvironmentalimpacts.DirectAirCaptureChapter5.DirectaircaptureaspartofacarbondioxideremovalportfolioAkeytechnologyfornetzeroPAGE51IEA.Allrightsreserved.KeyfeaturesofthemainCDRapproachesandtechnologiesApproachBECCSDACSEnhancedweatheringofmineralsLandmanagementandbiocharproductionOceanfertilisation/alkalinisationARApproachtypeTechnology-basedTechnology-basedEnhancednaturalprocessesEnhancednaturalprocessesEnhancednaturalprocessesNature-basedCurrentmaturitycategory(TRL)Largeprototype(TRL6)Largeprototype(TRL6)Concept(TRL1-3)Smallprototype(TRL4)Concept(TRL1-3)Largeprototype(TRL6)StoragetypeandpermanenceGeological,highGeological,highBiosphere,highBiosphere,mediumOcean,mediumBiosphere,lowCarbonremovalpotential(cumulativeto2100,GtCO2)100-1170108-1000100-36778-146855-102780-260CO2capturecost(USD/tCO2)15-80125-33550-20030-120-5-50WaterrequirementHighLowHighLow-HighLandrequirementMediumLowMediumMedium-HighIEA.Allrightsreserved.Notes:BECCS=bioenergywithCCS;CCS=carboncaptureandstorage;DACS=directaircaptureandstorage;TRL=technologyreadinesslevel.Estimatesforcarbonremovalpotentialarenotadditive,asCDRapproachespartiallycompeteforresources.Landrequirementexcludesenergysources.Pleasenotethatcarbonremovalpotentialisscenario-dependent.Sources:IEAanalysis;IEA(2020);IPCC(2021);CDRPrimer(2021);EASAC(2018);Fussetal.(2018);Iyeretal.(2021).DirectAirCaptureChapter5.DirectaircaptureaspartofacarbondioxideremovalportfolioAkeytechnologyfornetzeroPAGE52IEA.Allrightsreserved.DACSpresentsanumberofadvantagescomparedtootherCDRapproaches.DACasacapturetechnologyisatTRL6(largeprototype)duetonumerousplantsbeinginoperation.Geologicalstorageofair-capturedCO2ensuresveryhighstoragepermanence(1000+years),whichisessentialwhenaimingforhigh-qualityremoval.Accordingtotheliteraturecitedinthetableabove,thecumulativecarbonremovalpotentialofDACSto2100isfourtimeshigherthanthepotentialfromAR,withamuchsmallerwaterandlandfootprint,whichishighingeneralforanybiomass-basedCDRoption(includingARandBECCS).Moreover,ittakesaroundacoupleofyearstobuildandstartoperatingaDACSplantatfullcapacity,whichcouldrunforupto25years(basedonsimilarindustries).ARtakesuptotenyearstorampuptothemaximumsequestrationrate,tothensaturatein20-100years’time(dependingonthespecies),effectivelyceasingCO2removalunlesssustainablymanaged.MainCDRoptionsInadditiontoDACS,CDRoptionsincludeBECCS,AR,enhancedweathering,biochar,andocean-basedapproaches.BECCS(bioenergywithCCS)involvesthecaptureandpermanentstorageofCO2fromprocesseswherebiomassisconvertedtoenergy.Asitgrows,biomassabsorbsCO2viaphotosynthesis;theCO2isreleasedduringrefiningoroncombustion(toproduceenergy),butcanbepermanentlycapturedandstored.Itsapplicabilityisbroadasitcanincludepowerplantsusingbiomass(oramixofbiomassandfossilfuels);pulpmillsforpaperproduction;limekilnsforcementproduction;andrefineriesproducingbiofuelsthroughthefermentation(ethanol)orgasification(biogas,biodiesel,hydrogen)ofbiomass.Waste-to-energyplantsmayalsoremoveCO2fromtheatmospherewhenfedwithbiogenicfuel.BECCSisatTRL6,withmorethantenfacilitiescurrentlycapturingCO2frombioenergyproductionandutilisationaroundtheworld;however,itslarge-scaledeploymentwillbelimitedbytheavailabilityofsustainablebiomass.AR(afforestationandreforestation)comprisestwoapproachesaimedatenhancingthenaturalCO2cyclebymeansoflandusemanagement.Whileafforestationaimstorepurposelandusebygrowingforests(oranyformofbiomass)wheretherewasnonebefore,reforestationaimstore-establishaforestwheretherewasoneinthepast.AmongallCDRoptions,ARandBECCSaretheonlytechniquescurrentlywidelyincludedinclimatemitigationscenarios(Gambhiretal.,2019;IPCC,2018;Rogeljetal.,2018),althoughtherangeofstorageestimatesisquitelarge(0.5-5GtCO2/yearin2050).WhileARhasalreadybeenapplied,hasrelativelylowcostsandcanprovidepositivesideeffects(suchasenhancementofbiodiversityandreducedsoilerosion),itcanalsocompetewithDirectAirCaptureChapter5.DirectaircaptureaspartofacarbondioxideremovalportfolioAkeytechnologyfornetzeroPAGE53IEA.Allrightsreserved.bioenergyproductionandfoodproductionforlanduse.Moreover,ARhasalargelandandwaterfootprint,anditscarbonremovalpotentialisnotpermanentandisalsodifficulttomeasure.Enhancedweatheringisanaturalprocessthattakesplacewhenacidraindissolvesminerals,whichthenreactwithCO2toformcarbonates.Enhancedweatheringaimstoacceleratethisprocess,forinstancebyreactingCO2witholivineorcalcium-silicatesinautoclaves,orbyspreadingfine-powderedolivineonfarmlandorforestland.AlthoughanumberofreviewsonCDRoptionsmentionthisapproach(Fussetal.,2016;Haszeldineetal.,2018;Minxetal.,2018),furtherinvestigationandR&Dareneeded,especiallyforthepurposeofclimatechangemitigation(enhancedweatheringhasbeentestedforacceleratingrecoveryfromacidrainortoincreaseharvestyieldsforsugarcaneproduction).Biocharisproducedbyslowlyheatingbiomassintheabsenceofoxygeninaprocesscalledslowpyrolysis.Theproductofthisthermalconversionprocessiscarbon-rich(60-90%)solidchar,whichcanbeusedtoenrichsoilsandthereforetoremoveCO2fromtheatmosphere.Althoughthisapproachhaspotential,itisyettobetestedonalargescale.Moreover,furtherstudiesareneededinordertoquantifybiochar’scarbonremovalpotential,thestabilityandpersistenceofcarboninsoilsinthelongterm,biochar’seffectonbiologicalorganisms,andpotentialco-benefitssuchasimprovedfertilisationefficiencyandreducedN2Oemissions.Approachesenhancingtheuseoftheoceanasacarbonsinkincludeoceanalkalinisation(geochemical,directaircapture)andoceanfertilisation(biological,indirectaircapture).Theoceanisthelargestnaturalcarbonsink,currentlyremovingaroundathirdofanthropogeniccarbonemissionsfromtheatmosphere.Whileoceanalkalinisationisthedirectconsequenceofenhancedweathering,oceanfertilisationaimstoincreasetheamountofCO2thatisbiologicallyremovedfromtheatmosphere.Themostcommonandknownsideeffectofoceanfertilisationiseutrophication.Neitheroceanalkalinisationnoroceanfertilisationhavebeentestedonalargescale,andenvironmentalconcernstogetherwithpublicacceptancemaypreventthistechnologyfrombeingdeployedatscale.AdditionalCDRoptionsincludesoilcarbonsequestration(basedonagriculturalmanagementpracticestoimprovesoilcarbonstorage),bluecarbon(therestorationofvegetatedcoastalecosystems)andpeatlandrestoration(storingcarboninsoilbycreatingorrestoringpeatlands).AccordingtotheIPCC,thesemethodspresentthehighestenvironmentalco-benefits,althoughtheyarealsocharacterisedbylowstoragepermanence.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE54IEA.Allrightsreserved.Chapter6.ScalingupthedeploymentofdirectaircaptureSupportfordirectaircaptureGrowingrecognitionofDACtechnologies’importantroleinmeetingnetzerogoalsistranslatingintoincreasedpolicysupportandinvestment.Sincethestartof2020,almostUSD4billioninfundinghasbeenannouncedspecificallyforDACresearch,developmentanddeployment(RD&D),whileleadingDACcompanieshaveraisedaroundUSD125millionincapital.PlansfornineDACfacilitiesarenowindevelopment.Ifalloftheseplannedprojectsweretogoahead,DACdeploymentwouldreacharound3MtCO2by2030;thisismorethan380timestoday’scapturerate,butamere3.4%ofthelevelofdeploymentneededintheNetZeroScenario.DACprojectsindevelopmentNameCountryTargetoperationdateCapturecapacity(tCO2/year)CO2useorstorageDACpilotplantAustralia2022365Storage(injection)HaruOnieFuelspilotplantChile2022-Use(syntheticfuels)Norske-fuelprojectNorway2023-Use(syntheticfuels)DAC1projectUnitedStates20251millionStorage(injection)DreamcatcherprojectUnitedKingdom2026Upto1millionStorage(injection)Air-to-fuelsplantCanada2026-Use(syntheticfuels)AtmosFUELprojectUnitedKingdom2029-Use(syntheticfuels)SizewellCnuclear-poweredDACUnitedKingdom-100Storage(injection)KollsnesprojectNorway-Upto1millionStorage(injection)DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE55IEA.Allrightsreserved.GovernmentsupportforDACisgrowingCountriesandregionsthathavetakenanearlyleadinsupportingDACresearch,development,demonstrationanddeploymentincludeCanada,theEuropeanUnion,theUnitedKingdomandtheUnitedStates.CountriesincludingAustralia,JapanandNorwayarealsoactivelysupportingDACdevelopment.MajorpubliclyfundedDACinitiativesbyregionProgramme/instrumentDescriptionCanadaClimateActionandAwarenessFundThefundisinvestingCAD206million(USD164million)tosupportprojectsthatwillreduceCanada’sGHGemissions,includingeffortstounderstandthepotentialfor,andimplicationsof,carbonremovaltechnologiesincludingDAC.NetZeroAcceleratorPartoftheStrategicInnovationFund,thisinitiativewasannouncedinDecember2020andfurtherenhancedbyCanada’sBudget2021toprovideatotalofCAD8billion(USD6.4billion)oversevenyearstosupportthedecarbonisationoftheindustrialsector.DACwithCO2useiseligibleasaclimate-neutralCO2feedstocktoproducelow-carbonproducts.CleanFuelStandardThestandardwillrequireliquidfuelsupplierstograduallyreducethecarbonintensityofthefuelstheyproduceandsell.Low-carbon-intensityfuelsincludethosemadefromsustainablysourcedbiomassandDAC.Budget2021ThebudgetincludedCAD319million(USD254million)oversevenyearsforNaturalResourcesCanadatofundRD&DtoimprovethecommercialviabilityofCCUStechnologies,includingDAC.EuropeanUnionHorizonEuropeDACprojectsareeligibleforsupportunderHorizonEurope,themainEUfundingprogrammeforresearchandinnovation,withatotalbudgetacrossallareasofEUR95.5billion(aroundUSD113billion).InnovationFundTheEUR10billion(USD11.8billion)fundwaslaunchedin2020tosupportinnovationinlow-carbontechnologiesandprocesses,includingCCUSandDAC.CommunicationonSustainableCarbonCyclesThecommunication,releasedinDecember2021,setsoutastrategytoincreaseremovalsofcarbonfromtheatmosphere.Itsuggeststhat5MtofCO2shouldberemovedannuallyby2030.UnitedKingdomDACandGHGRemovalCompetitionThiscompetition,announcedin2020,willprovidefundingfortechnologiesthatenabletheremovalofGHGsfromtheatmosphere.TotalbudgetisuptoGBP100million(USD137million).NetZeroStrategyThestrategyidentifiesaneedfor75-81MtCO2ofengineeredcarbonremovalsviaDACSandBECCSby2050.DACmayalsobenefitfromannouncedfundingofGBP180million(USD248million)tosupportproductionofsustainableaviationfuels.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE56IEA.Allrightsreserved.Programme/instrumentDescriptionUnitedStates45QtaxcreditThistaxcredit(introducedin2008andexpandedin2018)providesUSD35pertonneofCO2usedinenhancedoilrecoveryandUSD50pertonneofCO2stored.ThecreditisavailableforDAConlyifthecapturecapacityoftheplantisabove100000tCO2/year.Thereareanumberofproposalstoincreasethevalueofthe45Qtaxcredit,includingintheBuildBackBetterAct,whichwouldprovideUSD180/tCO2forDACS.CaliforniaLowCarbonFuelStandardDACprojectsanywhereintheworldareeligibletoreceiveLCFScredits,providedtheprojectsmeettherequirementsoftheCarbonCaptureandSequestrationProtocol(including100yearsofstoragemonitoring).TheLCFScreditstradedatanaverageofaroundUSD200/tCO2in2020.InfrastructureInvestmentandJobsActAlmostUSD12billioninCCUSsupportwasincludedinthisact,whichwasenactedinNovember2021.ThisincludesUSD3.5billioninfundingtoestablishfourDAChubs(1MtCO2peryearandabove)andrelatedtransportandstorageinfrastructure.DACprojectsarealsoeligibleforadditionalCCUSfundingsupportincludedintheactofaroundUSD0.5billion.ADACPrizeprogrammewasalsofullyfundedbytheinfrastructurepackage,withUSD100millionforcommercial-scaleprojectsandUSD15millionforpre-commercialprojects.CarbonNegativeShotThiswasannouncedduringCOP26inNovember2021asacallforinnovationintechnologiesandapproachesthatwillremoveCO2fromtheatmosphereanddurablystoreitatmeaningfulscalesforlessthanUSD100/tonneofCO2-equivalent,includingDAC.DOEfundingprogrammesMultiplefundingprogrammesspecificallyforDACwereannouncedinMarch2020(USD22million),January2021(USD15million),March2021(USD24million)andOctober2021(USD14.5million).JapanMoonshotGoal4TheMoonshotGoal4(asubsetoftheMoonshotR&DProgram,launchedin2019withatotalbudgetofYEN100billion[USD1billion])focuseson“therealisationofasustainableresourcecirculationtorecovertheglobalenvironmentby2050”.Inordertoreachthisgoal,theMoonshotGoal4includesR&DfundingofYEN20billion(USD200million)formultipleinnovativetechnologies,includingDAC.Notes:GHG=greenhousegases;DOE=DepartmentofEnergy.UnitedStatesTheUnitedStateshasestablishedanumberofpoliciesandprogrammestosupportDACRD&D.DACplantswithacapturecapacityabove100000tCO2/yearareeligibleforthe45Qtaxcredit,providingUSD35pertonneofCO2usedinenhancedoilrecoveryandUSD50pertonneofCO2stored.DACplantsofanysizeareeligiblefortheCaliforniaLCFScredit(withthesecreditstradingatanaverageofUSD200/tCO2in2020),providedtheprojectsmeettherequirementsoftheCarbonCaptureandSequestrationProtocol.TheCaliforniaLCFSandthe45QtaxcreditarecomplementarypoliciesthatallowDACprojectstotakeDirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE57IEA.Allrightsreserved.advantageofbothincentives.Thereareanumberofproposalstoincreasethevalueofthe45Qtaxcredit,includingintheBuildBackBetterAct(passedbytheHouseofRepresentativesinNovember2021)whichwouldallowacreditofUSD85pertonneofCO2capturedandstoredviacertainindustrialapplicationsandUSD180pertonneforDACS.Moreover,theactproposestolowertheDACcapacitythresholdfor45Qfrom100000tCO2to1000tCO2.TheDepartmentofEnergyannouncedfundingspecificallyforDACR&DinMarch2020(USD22million),January2021(USD15million),March2021(USD24million)andOctober2021(USD14.5million).Furthermore,almostUSD12billioninCCUSsupportwasincludedintheUSD1trillionInfrastructureInvestmentandJobsActsignedintolawinNovember2021.Thisincludesfunding(USD3.5billion)toestablishfourDAChubs(1MtCO2andabove)andrelatedtransportandstorageinfrastructure,aswellasadditionalfundingforwhichCCUSandDACprojectsareeligible(aroundUSD8.5billion).ADACPrizeprogrammewasalsofullyfundedbytheinfrastructurepackage,includingUSD100millionforcommercial-scaleprojectsandUSD15millionforpre-commercialprojects.DuringCOP26inNovember2021,theDepartmentofEnergylaunchedtheCarbonNegativeShot,aninitiativeaimedatsupportingvariousCDRapproaches–includingDAC–toachievelarge-scaledeploymentwithinadecadeatUSD100/tCO2orless.Thisinitiativehasdefinedgood-quality,large-scaleremovalsasnotonlylow-costremovals,butalsothoseachievingstoragepermanence(100yearsormore)andwithrobustaccountingoffulllifecycleemissions.PolicysupportforandlevelisedcostofDACSin2020and2030,UnitedStatesIEA.Allrightsreserved.Notes:DACiseligibleforthe45Qtaxcreditonlyforcapturecapacitiesabove100000tCO2/year.Proposedpolicysupportin2030includestheincreasedUSD180/tCO2taxcredit(CO2storageonly).Referencecapturecapacityscale=1MtCO2/year.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE58IEA.Allrightsreserved.CanadaInDecember2020,CanadaannouncedinvestmentofuptoCAD3billion(USD2.4billion)inanewStrategicInnovationFund(SIF)NetZeroAcceleratorInitiative,whichwasfurtherenhancedbyCanada’sBudget2021inApril2021toprovideatotalofuptoCAD8billion(USD6.4billion)oversevenyearstosupportprojectsthatwillhelpreducegreenhousegasemissionsacrosstheCanadianeconomy.ThecompanyCarbonEngineeringwassuccessfulinsecuringaCAD25million(USD20million)grantfromanearlierstreamofSIFfundingin2019,whichfollowsGovernmentofCanadasupportviaNaturalResourcesCanadaofCAD4.25million(USD3.4million)undertheEnergyInnovationProgramaswellastheImpactCanadaSky’stheLimitChallengetoproducemade-in-Canadasustainableaviationfuel.AlongsideprivatefundingofoverCAD100million(USD80million),theseinvestmentsaresupportingtheconstructionandoperationofCarbonEngineering’snewInnovationCentreinSquamish(BritishColumbia)andalsoafullyintegratedDACandair-to-fuelsplant(capturecapacity4.5tCO2/day).Additionally,thegovernmentofBritishColumbia’sInnovativeCleanEnergyFundiscontributingCAD2million(USD1.6million)tosupportpreliminaryengineeringanddesignofacommercialfacilitycapableofproducingupto100millionlitresofultra-lowcarbonfueleachyearusingair-capturedCO2.TheCanadianfederalgovernmenthasalsolaunchedtheClimateActionandAwarenessFund,whichispositionedtoinvestCAD206million(USD164million)overfiveyearstosupportCanadianprojectsthatwillreduceCanada’sgreenhousegasemissions.Undertheadvancingclimatescienceandtechnologycategory,oneofthethemesistounderstandthepotentialfor,andimplicationsof,CDRtechnologies,withanemphasisonDACandmeasurementandmonitoringtoolsfornature-basedcarbonremoval.SimilartotheCaliforniaLCFS,theCanadianfederalgovernmenthasproposedtheimplementationoftheCanadaCleanFuelStandard.Thisstandardisaimedatreducingthecarbonintensityofliquidfuelsthroughasystemwherecreditscanbegeneratedbyundertakingprojectsthatreducethelifecycleintensityoffossilfuels.SuchprojectsincludeCCUS,supplyingcustomerswithlow-carbon-intensityfuels,andinvestinginadvancedvehicletechnologies.Low-carbon-intensityfuelsincludethosemadefromsustainablysourcedbiomassandDAC.TheCleanFuelStandardshouldbefinalisedandenforcedin2022.AninvestmenttaxcreditforCCUSwasproposedintheCanadianBudget2021.Thistaxcredit,whichcouldbecomeavailableassoonas2022,isanticipatedtobeavailableacrossdifferentindustrialsectors,includingDACforCO2useorgeologicalstorage(notforenhancedoilrecovery).Inadditiontotheproposedinvestmenttaxcredit,thefederalbudgetincludesCAD319million(USD254million)directedtowardsNaturalResourcesCanadaforCCUSRD&D.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE59IEA.Allrightsreserved.EuropeanUnionTheEuropeanCommissionhasbeensupportingDACthroughvariousresearchandinnovationprogrammes,includingtheSeventhFrameworkprogrammeanditssuccessors(i.e.theHorizon2020programmeandtheHorizonEuropeprogramme),andalsothroughtheInnovationFund.Celbicon,Carbfix,STORE&GOandNEGEMarenotableprojectsthathavebeen(atleastinpart)fundedbytheEuropeanCommissionandhaveaDACcomponent.Theseprojects,whichrangefromtechno-economicassessmentstodemonstrationofDACtechnologies,maynothavebeenpossiblewithouttheHorizon2020grantasitmadeupalargeportionoftheirtotalbudget.SelectedDACprojectsthatreceivedpublicfundinginEuropeCelbiconCarbfixandCarbfix2STORE&GONEGEMDuration2016-20192011-20212016-20202020-2024FocusCO2tochemicals(PHAbioplastic,methane)CO2removalviamineralisationinbasaltformationRenewablepowertogas(methane)Techno-economicandsocialassessmentofCO2removalFundingsourcesEUH2020,EuropeanScienceFoundation,AustriangovernmentViennaResearchGroupforYoungInvestigatorsEUFP7,EUH2020,USDOE,theNordicCouncilofMinisters,GEORGEUH2020,SwissgovernmentEUH2020Totalfunding(EURmillion)6.23.8285.8FundingdistributionNotes:GEORG=IcelandicGeothermalResearchCluster;H2020=Horizon2020;FP7=SeventhFrameworkProgramme;PHA=polyhydroxyalkanoates.Sources:IEAanalysisbasedonCelbicon(2022),Capture,ELectrochemicalandBIochemicalCONversiontechnologies;Carbfix/Carbfix2;STORE&GO(2020)Power-to-GastechnologyintothefutureEuropeanenergysystem;NEGEM(2022),QuantifyingandDeployingResponsibleNegativeEmissions;Snæbjörnsdóttir,(2018),Reactionpathmodellingofin-situmineralisationofCO2attheCarbFixsiteatHellisheidi,SW-Iceland;AbdelAzxim,(2017),Thephysiologyoftraceelementsinbiologicalmethaneproduction;Rittmann,(2018),Kinetics,multivariatestatisticalmodelling,andphysiologyofCO2-basedbiologicalmethaneproduction;Mauerhofer(2018),PhysiologyandmethaneproductivityofMethanobacteriumthermaggregans.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE60IEA.Allrightsreserved.TheEUInnovationFundwaslaunchedin2020,withaninitialbudgetofEUR10billion(USD11.8billion)overtenyears,2020-2030.Projectseligibletoreceivefundingincludethoseaimedatdecarbonisingenergy-intensiveorcarbon-intensiveindustrialproduction,CCUS,renewableenergygeneration,andenergystorage.Grantawardsaredependentonprojectsize,butcancoverupto60%ofrelevantprojectcosts.TheEuropeanUnionhasalsobeguntoenactpolicythatcaneitherdirectlyorindirectlysupportDAC.InApril2021theEuropeanParliamentandCouncilreachedaprovisionalagreementontheEuropeanClimateLaw,includingalegalobjectivefortheEuropeanUniontoachieveclimateneutralityby2050andacommitmenttonegativeemissionsafter2050.Toachievethesegoals,theEuropeanUnionrecognisestheneedtoenhancecost-effectivecarbonremovaltechnologies.InJuly2021itlaunchedtheFitfor55package,aimedatrevisingitsclimate,energyandtransport-relatedlegislation.Thepackageincludesaproposaltorevisetheregulationongreenhousegasemissionsandremovalsfromlanduse,landusechangeandforestry(LULUCF).Whileland-basedCDRapproachesareexplicitlymentionedinthepackage,technology-basedoptionssuchasBECCSandDACSarenotcurrentlyincluded.ThepackageisalsoproposingtoincreasethebudgetfortheInnovationFundandtoincludeCO2mineralisationasaneligibleemissionsavoidancetechnologyundertheEUemissionstradingsystem(ETS).AnotherlegislativeproposalwithintheFitfor55packageistheReFuelEUAviation,whichwillintroduceanobligationforjetfuelsupplierstoblendapercentageofsustainableaviationfuelsintofossil-derivedjetfuel(2%in2025and5%in2030).Sustainableaviationfuelscancomefrombiofuelsorintheformofe-kerosene,whichisproducedfromrenewableenergyandatmosphericCO2,sourcedfromDACoperations.30InDecember2021theEuropeanCommissionreleaseditsfirstCommunicationonSustainableCarbonCycles,whichincludesashort-tomedium-termactionplanandalong-termstrategyoncarbonremoval.Thestrategylooksatcarbonremovalcertificationschemesandfuturepolicyframeworks,includingland-basedapproaches(basedonsoil-andbiomass-basedremoval)aswellaswood-basedconstructionmaterials,BECCSandDACS.Thecommunicationsuggeststhat5MtofCO2shouldberemovedannuallyby2030fromtheatmosphereandpermanentlystoredthroughthesesolutions.30Itshouldbenotedthatin2030thetargetfore-keroseneusedinjetfuelis0.7%,withbiofuelsmakinguptheremaining4.3%.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE61IEA.Allrightsreserved.UnitedKingdomInJune2020theUKgovernmentannouncedtheNewDealforBritain,whichoutlinedabudgetofGBP100million(USD137million)togotowardsR&DforDAC.Inresponse,theDepartmentforBusiness,Energy&IndustrialStrategylaunchedtheDACandGreenhouseGasRemovalcompetition,withthefirst-stageselectionofproposalsannouncedin2021.Outofthe24winners,fiveprojectswerespecificallyfocusedontheadvancementofDACtechnologies.31Thegovernmentisalsoshowinginterestinadaptingthepost-BrexitETSschemetoincludecarbonremoval.CarbonremovalcreditswouldbetradedalongsidetraditionalallowancesandcouldsupportDACdeployment.InOctober2021thegovernmentsetoutaNetZeroStrategyaimedatachievingnetzeroemissionsby2050.Thestrategyidentifiesaneedforbetween75Mtand81MtofengineeredcarbonremovalsviaDACSandBECCSby2050(equivalenttoaround45-80%ofthetotalemissionscapturedacrosstheUnitedKingdom).UndertheNetZeroStrategy,DACmayalsobenefitfromannouncedfundingofGBP180million(USD248million)tosupporttheproductionofsustainableaviationfuels.PrivatesupportandinvestmentfordirectaircaptureistakingoffPrivate-sectorsupportforandinvestmentinDAChasexpandedinrecentyears,withorganisationssuchasBreakthroughEnergyVentures,PreludeandLowerCarbonCapitalinvestinginearly-stagestart-upsaswellasmoreestablishedcompaniesthatarealreadycapturingCO2fromtheatmosphere.Theseprivateinvestmentscanassistinthedevelopmentoflarge-scaleoperations,de-riskingneweroremergingtechnologies,andpropellingDACforwardintheabsenceofotherincentivesforcarbonremovalandstorage.FurthersupportforDAChascomefromprogrammessuchastheXPRIZE(offeringuptoUSD100millionforasmanyasfourpromisingcarbonremovalproposals,includingDAC)andBreakthroughEnergy’sCatalystProgram(whichraisesmoneyfromphilanthropists,governmentsandcompaniestoinvestincriticaldecarbonisationtechnologies,includingDAC).PrivateinvestmentroundsforDACfirmshavealsobeensuccessful:in2020Climeworksraisedthelargest-everDACinvestment,securingUSD110million.31Theseare:DirectAirCapturepoweredbyNuclearPowerPlant,ledbySizewellC;DRIVE(DirectRemovalofCO2throughInnovativeValorisationofEmissions),ledbyMissionZeroTechnologies;ProjectDreamcatcher–LowCarbonDirectAirCapture,ledbyStoregga;SMART-DACSustainableMembraneAbsorption&RegenerationTechnologyforDirectAirCapture,ledbyCO2CirculAir;andEnvironmentalCO2Removal,ledbyRolls-RoyceandCSIRO.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE62IEA.Allrightsreserved.Inparallel,therehasbeensubstantialgrowthinnewcommercialpartnershipsandagreementstodevelopanddeployDACtechnologies.DAC1,aprojectfinancedanddevelopedby1PointFive(partofOxyLowCarbonVentures),issettobecometheworld’slargestDACfacility,withcommissioningplannedfor2024.TheprojectistobelocatedinthePermianBasinintheUnitedStatesandwilluseCarbonEngineering’sDACtechnology.Theprojectissupportedbyamulti-milliondollarinvestmentfromUnitedAirlines,andmaybeeligibleforCaliforniaLCFSand45Qtaxcredits.InJune2019GlobalThermostatandExxonMobilsignedajointdevelopmentagreement(whichwassubsequentlyexpandedinSeptember2020)aimingtoassessthefeasibilityofusingGlobalThermostat’scarboncapturetechnologyforindustrialaswellasatmosphericcarboncaptureapplications.AfurtherexampleincludesthejointdevelopmentagreementsignedbySvante(acarboncapturecompanythatusessolidadsorbentstocaptureCO2fromindustrialfluegases)andClimeworkstoadvancethedeploymentoftheirtechnologiesforbothindustrialandatmosphericCO2capture.ThecompaniesareplanningtousewasteheatfromSvante’sCCUStechnologytopowerClimeworks’DACplanttodeliverhigh-value-addedCO2productstocustomers.Finally,thecollaborationbetweenCarbonEngineeringandStoregga(theprojectdeveloperoftheAcornCCSprojectintheUnitedKingdom)planstodeployacommercial-scaleDACprojectintheUnitedKingdomby2026.PotentialsourcesoffinanceforDACcompaniesDACcompanies,includingstart-ups,haveanumberofwaysinwhichtheycansecureprivateinvestment:Angelinvestorsorangelgroups:moneyprovidedbyhigh-net-worthindividualsorgroupsofindividuals,usuallyfrompersonalfunds,inexchangeforapercentageofthecompany’sequity.Beforecommittingtopurchaseequity,angelgroupsmayrequireadditionaldetaileddocumentationandevaluationsforprojectstobeeligibleforsustainedfunding.Venturecapital:moneyprovidedbyhigh-net-worthfirmsinexchangeforapercentageofthecompany’sequity.ThistypeoffinancialinvestmenthasbeenprovidedbyBreakthroughEnergyVentures(startedbyBillGatesandalimitednumberofprivateinvestors)andLowerCarbonCapital(startedbyChrisSacca).Preliminarycustomeragreements:moneyprovidedtocompaniesthroughthesaleofaproductorservice.InrelationtoDAC,thiscantakeplaceasafundingDirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE63IEA.Allrightsreserved.entitybuyingcarbonremovalasaserviceatahigherinitialpricesotheprofitscanbeusedtofurtherbusinessorphysicalassetdevelopment.ThistypeoffinancialinvestmenthasbeenmadebyStripeandMicrosoftintheircarbonremovalinvestmentportfolios.Philanthropicactivity:moneyreceivedthroughphilanthropicactivitieseitherasdonationsorviacompetition.Aninvestmentlikethisisnotinexchangeforanyequityanddoesnotrequireanypayback.AnexampleofthisistheUSD100millionXPRIZECarbonRemovaladministeredbytheXPRIZEFoundationandfundedbyElonMuskthroughtheMuskFoundation.Businessloans:moneylentbybanksorotherfinancialinstitutionsintheformofdebtthatmustberepaidinadditiontointerestontheloan.Somestart-upcompaniespreferthismethodtoavoidhavingtosplitequityandtoretaindecisionautonomy.Asattitudestowardsclimate-friendlyandcleantechnologyadvance,morebanksandfinancialinstitutionsareprovidingloanstothesesectorsatcompetitiveinterestrates.AnexampleistheIndustrial,CleanandEnergyTechnologyVenturefundthroughtheBusinessDevelopmentBankofCanada.Manyoftheirenvironmentallyfocusedinvestmentssofarhavebeenincompaniesthataimtoprovidedecarbonisedenergy.IthasalsoinvestedinCarbonCure,buthasnotinvestedinanyDACcompaniestodate.BusinessmodelsfordirectaircaptureTherearetwoprimarycommercialdriversforinvestinginDACtechnologies:1)sellinghigh-qualitycarbonremovalserviceswhenDACiscombinedwithCO2storage,and2)sellingclimate-neutralCO2asafeedstockforarangeofproducts,includingaviationfuelsandbeveragecarbonation.Todate,mostDACfacilitiesarerelativelysmallandaresellingtheCO2,withonlytwofacilitiesprovidingcarbonremovalservices.High-qualitycarbonremovaltobalanceemissionsThegrowingnumberofgovernmentsandcorporationsannouncingnetzerogoals,togetherwithmaturingmarketsforlow-carbonproducts,haveboostedinterestanddemandforcarbonremovalsolutions.Formanycompanies,meetingtheirclimatetargetswillrequiresomeformofremovaltobalanceemissionsforwhichtherearelimitednear-termmitigationopportunities(includinginsectorssuchasaviationandheavyindustry).InthecaseofMicrosoft,anambitiouscorporatetargettobecarbonnegativeby2030inherentlyrequiresCDR.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE64IEA.Allrightsreserved.Atthemomenttechnology-basedCDRapproaches,includingDAC,areamongthemostexpensiveCDRoptions,yetarestillattractingcommercialinterestduetotheirhighqualitywhenassessedagainstkeycriteria,particularlyadditionality,durabilityandmeasurability.AnassessmentofDACSashigh-qualityCDRCDRinvestmentcriteriaDescriptionDACevaluationofperformance1.AdditionalityThecarbonremovalactivitywouldnototherwiseoccurandsoresultsinnetcarbonremovalcomparedtoabaselinescenariointheabsenceofinvestment.Veryhigh2.DurabilityTheintendedmethodofstorageforacarbonremovalsolutionispermanent,withlowlikelihoodofbeingre-releasedintotheatmospherefromvoluntaryorinvoluntaryevents.Veryhigh3.MinimalemissionsdisplacementThecarbonremovalactivityhasminimalriskofdisplacingactivitiesandthuscausingfurtherCO2emissions.Mediumtohigh4.CarbonaccountingThecarbonremovalactivityresultsinnetnegativecarbonemissionstotheatmospherewhenupstreamanddownstreamemissionsarealsoaccountedfor.Theseactivitiescanquantifythecarbonthatisremoved.High5.DonoharmThenegativeimpactsofthesolutionatlargescaleshouldbeminimal.MediumtohighCriteriaadaptedfromCarbonDirect,https://carbon-direct.com/wp-content/uploads/2021/03/CD-Principles-for-Carbon-Removal.docx.pdf.DACcompaniesareofferingcommercialremovalservicestoindividualsaswellascompanieswillingtopayarecurringsubscriptiontohaveCO2removedfromtheatmosphereandstoredundergroundontheirbehalf.Thepriceofthesubscriptionvaries(dependingontheamountofremovalpurchased)fromUSD600/tCO2toUSD1000/tCO2,althoughpricedetailsforthelargercommercialdealsarenotavailable.CompaniesincludingMicrosoft,Stripe,ShopifyandSwissRehavepurchasedfutureDACremovalunits,eachrepresentingaunitofCO2toberemovedfromtheDirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE65IEA.Allrightsreserved.atmosphere,andbuildinganearlymarketforDAC-basedCDR.Someoftheseagreementsarehybrid,whereinthecompanypurchasingtheremovalunitsiseffectivelysupportingthecapitalinvestmenttobuildtheDACplantthatiseventuallygoingtocaptureCO2fromtheatmosphere.Forinstance,UnitedAirlinesisdirectlyinvestinginDACinlinewithitscommitmenttobecomecarbonneutralby2050,whileMicrosoftispurchasingDACremovalfromClimeworksand,throughitsClimateInnovationFund,isalsoinvestinginOrca,thelargestoperatingDACplantforcarbonremoval.ThevalueofDACinaCDRportfoliohasbeenhighlightedbyMicrosoft,whichdocumentedthelessonsandchallengesofsecuring“high-quality”CDR.Thecompanyreflectedonitsexperienceofpurchasing1.3MtofCO2removal,offersofwhichrangedfromprojectstoexpandforestsinPeru,NicaraguaandtheUnitedStatestotheinvestmentintheOrcaplant.UltimatelyMicrosoftidentifiedarangeofissuesfortheCDRmarket.Thisincludedinconsistentdefinitionsofnetzero,poormeasurement,monitoringandverification(MMV),poorcarbonaccounting,immaturemarketsforremovalsandoffsets,questionsaboutthepermanenceofthecarbonstorage,andcertainpositiveandnegativeexternalitiesnotbeingaccountedfor(e.g.wateruse,landuseandbiodiversity).Outof189proposalsreceivedbyMicrosoft(offering154MtCO2ofremoval),only55Mtwereimmediatelyavailable,andamere2MtCO2–includingDAC–metthecompany’scriteriaforhigh-qualityCO2.Thefindingsunderscoredthatthesupplyofsolutionscapableofpermanentlyremovingandstoringcarbonviablyiscurrentlyaverysmallproportionofthatneededtoreachnetzeroemissionsby2050.MuchofthepurchasingofCDRcurrentlyoccursinvoluntarycarbonmarketsratherthanbeingdrivenbyregulatoryrequirementsorcomplianceschemes.Infact,carbonremovalhasyettobeincorporatedintomostdomestic,regionalorinternationaltradingschemes,includingtheEUETS,althoughtheEuropeanCommissionisnowdevelopingacarbonremovalcertificationschemethataimstoprovidearobustandtransparentcarbonaccountingframeworkforcarbonremovalactivities.CreditingbaselinemethodologiesforissuingcarbonremovalcreditsfromDACSininternationalcarbonmarketsarecurrentlylacking,althoughsomeinitiatives,suchastheCCS+initiative,areworkingtodevelopthem.Further,theIPCCGuidelinesforNationalGreenhouseGasInventoriesdonotcurrentlyincludeamethodologyforaccountingfortheemissionsremovedbyDACS.ThismeansthattheabatementfromDACfacilitiescannotbecountedtowardsmeetinginternationalemissionsmitigationtargetsundertheUNFCCC.ThiswascitedasareasonfornotincludingDACintheAustralianEmissionsReductionFund,whichincorporatedanewmethodologyforCCUSin2021.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE66IEA.Allrightsreserved.DACcertificationandaccountingwithinaCDRportfolioThescale-upofDACconsistentwithnetzerogoalswillrequirerobustregulatoryframeworksandcertificationschemesthatcanprovidethemarketwithconfidenceintheuseofDAC-basedcarbonremoval.Inmanyways,thecarbonaccountingforDACisnotaschallengingasforsomenature-basedCDRsolutions,astheCO2capturedandstoredcanbeaccuratelymeasured.ButmajorconsiderationsandfutureneedsforthecertificationandaccountingofDACwithinaCDRportfolioinclude:•TransparentandconsistentLCAmethodologies:LCAtoolsareneededtoverifythatmoreCO2hasbeencapturedandstoredthanemittedbyDACoperationsandthereforethatcarbonhasbeenremoved.CriticalfactorswillincludetheenergyusedbytheDACfacility,anyembodiedCO2intheDACfacility,emissionsassociatedwithconsumables,andanyleakageduringthecapture,transportandstorageoftheCO2.HavingaconsistentandinternationallyagreedmethodologyfortheLCAofDACfacilitiesalongsideotherCDRapproachescansupportfuturemarketsandenablecomparisonacrossCDRoptions.•Measurement,monitoringandverification(MMV)ofCO2stored:thepermanenceofCO2storageisavitalfactorforcarbonremovalviaDACfacilities.Internationalstandards(ISO27914:2017)andcountry-levelregulatoryframeworkshavebeendevelopedforgeologicalstorageofCO2,includingMMVtechnicalrequirementsandbestpracticesthatcanbeadoptedbypolicymakersandregulators.CarbonaccountingframeworksforCDRwillneedtoconsiderthepotentialforreversalorre-releaseoftheCO2;inthecaseofgeologicalstoragethisriskisverylow.•Avoidanceofdouble-counting:thedouble-countingofemissionremovalscanhappenifcarbonremovalsareissued,claimedorsoldbytwodifferentschemesorbythesameschemetwice.Certificationofcarbonremoval(includingthroughcarbonremovalcertificates,orCRCs)canmitigatetheriskofdouble-countingbyprovidingaverifiedandtraceablecreditforremoval.•Internationaltransferability:theeligibilityofDACfacilitiesunderArticle6oftheParisAgreementwillbeimportanttofacilitateinternationalco-operationandinvestment,includingdirectinginvestmenttothoseregionswhereDACcanbedeployedatleastcost.•AccountingforDACinnationalinventories:IPCCGuidelinesforNationalGreenhouseGasInventorieswillneedtobeupdatedtoincludeamethodologyforDACinorderforthesefacilitiestobecountedinnationalabatementefforts.EffortstodeveloprobustaccountingandcertificationforDACandotherCDRapproachesareunderway,includingthroughtheMissionInnovationCDRMissionDirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE67IEA.Allrightsreserved.launchedatCOP26.InJuly2021theXPRIZECarbonRemovalannouncedawardsofUSD100000forprojectsfocusedontechnologiesormethodologiesforimprovingthestandardsofassessment,ortheprecision,accuracyandtimerequiredforcarbonmeasurements.SellingtheCO2foruseinindustrialapplicationsMostDACfacilitiescurrentlyinoperationgeneraterevenuefromsellingthecapturedCO2,includingforbeveragecarbonationandgreenhousecrops.WhilethelargestindustrialusesofCO2todayareinfertiliserproductionandenhancedoilrecovery–togetheraccountingformorethan200MtCO2everyyear–futurelarge-scaleopportunitiestouseCO2includetheproductionofchemicals,fuelsandbuildingmaterials.WhilesomeoftheseapplicationscanresultintheCO2beingstored(includinginbuildingmaterialsandsomeplastics),mostuseswillresultintheCO2beingreleasedtotheatmosphereinthenearterm,including(forexample)whentheCO2-containingfuelsarecombusted.Forthisreason,compatibilitywithnetzeroincreasinglyrequirestheCO2usedintheseapplicationstobebiogenicorcapturedfromtheair.IntheIEANetZeroScenario,around350Mtofair-capturedCO2isusedtoproducesyntheticfuelsin2050,includingforaviation,supportingoneofthefewpathwaystodecarbonisethissector.CompaniessuchasNorske-fuelsaretodaydevelopingsyntheticfuelswithCO2capturedfromDAC,buttheprocessremainsexpensiveandthesefuelscurrentlycostmorethanfivetimesfossil-basedfuels.Successfulcommercialisationofthesefuelswillrequirefurtherinnovationandpolicysupporttoachievecostreductions.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE68IEA.Allrightsreserved.Simplifiedlevelisedcostoflow-carbonfuelsforlong-distancetransport,2020IEA.Allrightsreserved.Notes:Forlong-distancetransportmodes,fossilfuelcostsreflectaUSD50/bbltoUSD100/bblcrudeoilcostrange,andthecarbonpricevariantrepresentsaUSD150/tCO2shadowcarbonprice,whichinpracticecouldtaketheformofotherregulatorypolicymeasuressuchasfuelstandards.SynthetichydrocarbonfuelcostrangesconsiderCO2frombioenergyorDAC,andhydrogenfromelectrolysispoweredbyadedicatedrenewableenergysystem.ElectricitypricesforhydrogenproductionrangefromUSD25/MWhtoUSD150/MWhacrossregionsandsources(grid,solarPV,on/offshorewind).Biofuelscovershydrotreatedvegetableoils(HVO)andbiomass-to-liquids(BTL).ReferencecapturecapacityscaleforDAC=1MtCO2/year.SixprioritiesfordirectaircapturedeploymentIncreasedinvestmentandpolicysupportwillbecriticaltoscaleupDACdeploymentthisdecade.Thissupportshouldtargetopportunitiestoreducecosts,refinetechnologiesandimproveglobalunderstandingofthetechnicalandeconomicpotentialforDACtosupportnetzerogoals.Inthenearterm,large-scaledemonstrationofDACtechnologieswillrequiretargetedgovernmentsupport,whilelonger-termdeploymentopportunitieswillbecloselylinkedtorobustCO2marketmechanismsandaccountingframeworksthatrecogniseandvalueCDRandair-capturedCO2asafeedstock.1.DemonstrateDACatscaleasapriorityDACmustbedemonstratedatscale,soonerratherthanlater,toreduceuncertaintiesaroundfuturedeploymentpotentialandcosts.Itisimportantthattoday’splannedlarge-scaleprojectsareabletobecomeoperational,providingessentiallearningsforDACtechnologiesandsupplychainsandpavingthewayforthemanyprojectsthatmustfollow.TargetedpoliciestosupportearlyinvestmentinDACfacilitiesincludecapitalgrantsandoperationalsubsidiessuchastaxcredits.ThesecanbecomplementedDirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE69IEA.Allrightsreserved.bymarket-basedmechanismsincludingemissionstradingframeworksorvoluntarycarbonmarkets,althoughthesemarket-basedmechanismsaloneareunlikelytosupportinvestmentinDACdeploymentatthescaleandpaceneededfornetzero.CertificationofDACwithintheseframeworksremainsadeploymentbarriertobeovercome(seebelow).SupportforDACdeploymentshouldrecognisethatthesetechnologiesareatanearlystageofcommercialisationandthatcapturingCO2fromtheairisinherentlymoreexpensivethatpoint-sourcecapture.ItisthereforeappropriatetoconsiderspecifictargetsorsupportforDACtechnologieswithinorinparallelwithbroaderCCUSpoliciesorprogrammes,forexamplethroughhighertaxcreditsforDAC.MainpolicyinstrumentsforDACdevelopmentanddeploymentCategoryTypesGlobalexamples(applicabletoDAC)GrantsupportCapitalfundingprovideddirectlytotargetedprojectsorthroughcompetitiveprogrammestoovercomehighupfrontcosts.UKCCSInfrastructureFund,USfundingforDAChubs(InfrastructureBill),EUInnovationFundOperationalsubsidiesTaxcreditsbasedonCO2captured/stored/used.Contract-for-difference(CfD)mechanismscoveringthecostdifferentialsbetweenproductioncostsandmarketprice.Feed-intariffmechanismswithlong-termcontracts.Cost-plusopenbookmechanismsinwhichgovernmentsreimbursesomecostsastheyareincurred,reducingriskforthecontractor.UnitedStates45QtaxcreditCarbonpricingCarbontaxeswhichimposeafinancialpenaltyonemissions.ETSsinvolvingacaponemissionsfromlargestationarysourcesandthetradingofemissionscertificates.EuropeanETSMarket-basedanddemand-sidemeasuresPublicprocurementoflow-CO2buildingmaterials,transportfuelsandpower,includingthoseproducedwithCCUS.CarbonremovalunitsorcreditsbasedonaverifiedrecordofCO2securelystored.Voluntarymarkets,CaliforniaLCFSInnovationandRD&DsupportFundingforRD&D,eitherdirectlyinstate-runresearchinstitutionsorindirectlythroughgrantsandothertypesofsubsidyforprivateactivities.CompetitiveapproachestosupportRD&Dforlow-carbontechnology.CarbonRemovalXPRIZE,EUHorizonEurope,USDepartmentofEnergyR&DprogrammesDACisnotcurrentlyrecognisedintheEUETS.Note:RD&D=research,developmentanddeployment.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE70IEA.Allrightsreserved.2.FosterinnovationacrosstheDACvaluechainInnovationwillbecentraltoreducingthecostofDACtechnologiesandsupportingacceleratedcommercialisation.PriorityinnovationneedsforDACinclude:ReducingtheenergyconsumptionneededtoseparateCO2throughemergingseparationtechnologies(e.g.electro-swingadsorption,membrane-basedseparation,moistureswingadsorption)andinnovativeapproachesabletoregeneratethesolventatlowtomediumtemperatures.ForL-DAC,advancingengineeringmaturityandmarketconditionstosupporttheavailabilityofrenewables-basedhigh-temperatureheattomaximisethecarbonremovalpotentialandprovideanalternativetocurrentdesignsbasedonco-captureofCO2fromnaturalgas.Reducingthecostoflarge-scaleopportunitiestouseair-capturedCO2,particularlyforsyntheticfuels.IncreasedRD&DspendingtodriveinnovationinDACtechnologiesatanationalandgloballevelwillbeessentialinthenearterm.AlthoughnotspecificallytargetedatDAC,initiativessuchastheUSCarbonNegativeShotandtheUSD100millionCarbonRemovalXPRIZEhavestrongpotentialtosupportDACtechnologiesanddrivecostreductions.Similarly,theMissionInnovationCDRMissionaimstoincreaseR&DonCDRandistargetingatleast100MtofCO2removalviaBECCS,DACandenhancedmineralisationby2030.3.IdentifyanddevelopCO2storageresourcesThepotentialforDACtosupportthelarge-scaleremovalofCO2fromtheatmosphererestsonthedevelopmentandavailabilityofgeologicalstorage.AlthoughglobalCO2storageresourcesareconsideredwellinexcessoflikelyneed,thetimeneededtoidentify,characteriseanddevelopspecificCO2storagesitescanbebetweenfiveandtenyears,dependingonthelocationandavailabilityofexistingdata.WithoutasubstantialincreaseininvestmentindevelopingCO2storageresources,theavailabilityofstoragecouldactasabrakeonthepotentialforDACandotherCCUSapplicationstocontributetonetzeropathways.GovernmentswillneedtoplayaleadingroleinidentifyinganddevelopingCO2storageinmanyregions,andparticularlywheregeologicalresourceshaveyettobewellexplored.Policyprioritieswillinclude:DevelopingandpublishingCO2storageatlaseswherelimiteddataisavailable.SuchatlaseshavebeendevelopedinmanyregionsandarenowcomplementedbytheCO2storageresourcescataloguereleasedbytheOilandGasClimateInitiativeandGlobalCCSInstitute.TheUSGeologicalSurveyandDepartmentofEnergyarealsoabletopartnerwithotherorganisationsandgovernmentstoprovidetechnicalexpertisetoevaluateCO2storageresources.DirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE71IEA.Allrightsreserved.ProvidingincentivesforcommercialdevelopmentofCO2storageandrelatedinfrastructure.Thisincludesthroughdirectfundingsupport(includinggrants)oroperationalsupport,suchastheNorwegiangovernment’scommitmenttotheNorthernLightsCO2transportandstorageproject(partoftheLongshipintegratedCCSproject).ImplementingrobustlegalandregulatoryframeworksthatensureappropriateselectionandoperationofCO2storagesites,aswellasensuringthesafeandsecurelong-termstorageofCO2.In2022theIEAplanstopublishtwoCCUShandbooksasaguideforpolicymakersondevelopingCO2storageresourcesandonlegalandregulatoryframeworksforCCUS.4.DevelopinternationallyagreedapproachestoDACcertificationandaccountingThedevelopmentofrobustandtransparentinternationalcertificationandaccountingmethodsforDACwillbeimportanttofacilitateitsinclusioninregulatedcarbonmarketsandtoprovideconfidenceintheemissionreductions(includingthroughCO2use)andremovalsassociatedwithDAC.ThisshouldincludeagreedmethodologiesfortheLCAofDACfacilities,ideallydevelopedinawaythatcanenableeffectivecomparisonwithotherCDRoptions.EffortstodevelopcertificationandaccountingstandardsforDAChavecommencedinseveralcountriesandregions,includingintheEuropeanUnion,theUnitedKingdomandtheUnitedStatesaswellasthroughinternationalinitiativessuchasthenewMissionInnovationCDRMission.Co-ordinationacrosstheseeffortswillbeimportanttopromoteinternationalconsistency.MitigationorremovalassociatedwithDACcannotcurrentlybecountedinnationalreportingduetotheabsenceofanaccountingmethodologyinthelatestIPCCGuidelinesforNationalGreenhouseGasInventories.ThisrepresentsamajorbarriertoscalingupinvestmentinDAC.5.AssesstheroleofDACandCDRinnetzerostrategiesAsanincreasingnumberofcountriesandcompaniespledgenetzerotargets,thefocusofdecisionmakershasshiftedtohowtoturnthesepledgesintoclearandcrediblepolicyactionsandstrategies.Todate,veryfewcountriesandcompanieshavedevelopeddetailedstrategiesorpathwaystoachievetheirnetzerogoals,butacriticalquestionforallwillbetheextenttowhichthesestrategieswillneedtorelyonCDRapproachesalongsidedirectemissionreductions.Fromaglobalperspective,itisclearthatCDRwillplayanimportant–andlikelyessential–roleinmeetingnetzerotargets.Onanationalorregionallevel,theDirectAirCaptureChapter6.ScalingupthedeploymentofdirectaircaptureAkeytechnologyfornetzeroPAGE72IEA.Allrightsreserved.roleforCDRwillvaryconsiderably,recognisingthatcountrieswilltakedifferentpathwaystonetzeroandtheultimatebalanceofremainingemissionsvsremovalswilldependonarangeoffactors,fromtheopportunitiesandchallengesfordirectmitigationinmajorsectorstothecostandavailabilityofnaturalsinks(nature-basedCDR)ortechnology-basedCDRapproaches.TheIEAhasconsistentlystressedtheabsolutepriorityofdirectmitigationefforts:CDRisnotanalternativetoearlyactionortodecisivelycuttingemissions.DACandotherCDRapproachesarepartoftheportfoliooftechnologiesandmeasuresneededinacomprehensiveresponsetoclimatechange.PromotingtransparencyandplanningfortheanticipatedroleofCDRinnetzerostrategiescansupporttheidentificationoftechnology,policyandmarketneedswithincountriesandregionswhilesupportingpublicunderstandingoftheseapproaches.6.Buildinternationalco-operationTheIEANetZeroby2050Roadmaphighlightedtheimportanceofinternationalcollaborationforinnovationandinvestment.TheLowInternationalCo-operationCasefoundthat,withoutgreaterinternationalco-operation,globalCO2emissionswillnotfalltonetzeroby2050.ForDACtechnologies,internationalco-operationcandrivefasterdeploymentandacceleratedcostreductionsthroughsharedknowledgeandreducedduplicationofresearchefforts.Internationalco-operationcanalsosupportthedevelopmentandharmonisationofLCAmethodologiesforDACtechnologies.InternationalorganisationsandinitiativessuchastheIEA,MissionInnovationCDRMission,theCleanEnergyMinisterialCCUSInitiative,andtheTechnologyCollaborationProgrammeonGreenhouseGasR&D(GHGTCP/IEAGHG)canprovideimportantplatformsforknowledge-sharingandcollaboration.Internationalfinanceentities,suchastheWorldBank,theEuropeanBankforReconstructionandDevelopmentandtheAsianDevelopmentBank,couldsupportinvestmentinDACfacilitiesinemergingmarketsanddevelopingeconomiesconsistentwithnationallydeterminedcontributionsandclimategoals.DirectAirCaptureAnnexAkeytechnologyfornetzeroPAGE73IEA.Allrightsreserved.AnnexAbbreviationsandacronymsARafforestation/reforestationBECCSbioenergywithcarboncaptureandstorageBTLbiomasstoliquidsCAPEXcapitalexpenditureCCScarboncaptureandstorageCCUScarboncapture,utilisationandstorageCDRcarbondioxideremovalCfDcontractfordifferenceCO2carbondioxideCOPConferenceofthePartiesDACdirectaircaptureDACSdirectaircaptureandstorageDOEDepartmentofEnergyEOethyleneoxideEOSeconomiesofscaleESAelectro-swingadsorptionETSemissionstradingsystemFEEDfront-endengineeringanddesignFOAKfirstofakindGEORGIcelandicGeothermalResearchClusterGHGgreenhousegasHVOhydrotreatedvegetableoilH2hydrogenH2OwaterIEAInternationalEnergyAgencyIEAGHGTechnologyCollaborationProgrammeonGreenhouseGasR&DIPCCIntergovernmentalPanelonClimateChangeLBDlearningbydoingLCAlifecycleassessmentLCClevelisedcostofcaptureLCFSLowCarbonFuelStandardL-DACliquidDACLULUCFlanduse,landusechangeandforestrym-DACmembrane-basedDACMMVmeasuring,monitoringandverificationNOAKnthofakindNetZeroScenarioNetZeroEmissionsby2050ScenarioOPEXoperatingexpensesDirectAirCaptureAnnexAkeytechnologyfornetzeroPAGE74IEA.Allrightsreserved.PHApolyhydroxyalkanoatesPVphotovoltaicR&DresearchanddevelopmentRD&Dresearch,developmentanddeploymentS-DACsolidDACSMRsteammethanereformingTRLtechnologyreadinesslevelUnitsofmeasurebblbarrelGJgigajouleGtgigatonneGtCO2gigatonnesofcarbondioxidekgkilogrammekm2squarekilometreMBtumillionBritishthermalunitsMtmilliontonnesMtCO2milliontonnesofcarbondioxideMWhmegawatthourttonnetCO2tonneofcarbondioxidetH2OtonneofwaterThispublicationreflectstheviewsoftheIEASecretariatbutdoesnotnecessarilyreflectthoseofindividualIEAmembercountries.TheIEAmakesnorepresentationorwarranty,expressorimplied,inrespectofthepublication’scontents(includingitscompletenessoraccuracy)andshallnotberesponsibleforanyuseof,orrelianceon,thepublication.Unlessotherwiseindicated,allmaterialpresentedinfiguresandtablesisderivedfromIEAdataandanalysis.Thispublicationandanymapincludedhereinarewithoutprejudicetothestatusoforsovereigntyoveranyterritory,tothedelimitationofinternationalfrontiersandboundariesandtothenameofanyterritory,cityorarea.IEA.Allrightsreserved.IEAPublicationsInternationalEnergyAgencyWebsite:www.iea.orgContactinformation:www.iea.org/about/contactTypesetinFrancebyIEA–April2022Coverdesign:IEAPhotocredits:©Shutterstock

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