未来能源研究所-电价对中重型汽车充电成本和负荷的影响 Impact of Electric Tariffs on Medium- and Heavy-Duty Vehicle Charging Costs and Loads

ImpactofElectricTariffsonMedium-andHeavy-DutyVehicleChargingCostsandLoads

BeiaSpiller,RuolinZhang,ElizabethB.Stein,EleftheriaKontou,andAlexanderYoshizumi

WorkingPaper25-22October2025

ResourcesfortheFuturei

AbouttheAuthors

BeiaSpillerisafellowandthedirectorforRFF’sTransportationProgram.PriortojoiningRFF,shewasLeadSeniorEconomistatEnvironmentalDefenseFund(EDF),wheresheworkedforalmostadecade.ShewasalsoaBoardmemberfortheAssociationof

EnvironmentalandResourceEconomiststhrough2024.Spillerisanenergyeconomist,withexperienceworkingonelectricityandtransportationissues.DuringhertimeatEDF,sheparticipatedinmanyelectricutilityproceedingsinNewYorkandCalifornia,withagoalofusheringinacleaner,moreefficientandequitableenergysystem.

RuolinZhangisaTransportationAnalystatKittelson&AssociatesandaPhDcandidateinTransportationEngineeringattheUniversityofIllinoisatUrbana-Champaign.She

specializesinsustainabletransportationsystemsplanningandoperations,withresearchfocusedonelectricvehicle(EV)infrastructureplanning,chargingmanagement,and

policyanalysis.Herworkintegratesdata-drivenmodeling,optimization,andspatial

analysistosupportequitableandsustainableEVadoptioninbothurbanandregional

contexts.AtKittelson,Zhangappliesheracademicexpertisetoreal-worldtransportationplanningprojects,bridgingresearchandpracticetoadvancesustainablemobility

solutions.

ElizabethB.SteinistheStatePolicyDirectorattheInstituteforPolicyIntegrityatNewYorkUniversitySchoolofLaw.Herworkcentersonstateutilitycommissionadvocacyrelatingtoelectricandgassystemdecarbonization,electrificationofenduses,

sustainableratedesignfortheenergytransition,andaccurateaccountingforenergytransition-relatedemissionsimpacts.BeforePolicyIntegrity,SteinwasLeadCounsel,EnergyTransition,atEnvironmentalDefenseFund.

EleftheriaKontouisanassistantprofessorofCivilandEnvironmentalEngineeringattheUniversityofIllinoisUrbana-Champaign.Herresearchfocusesonsustainableand

electrifiedtransportationsystemsplanningandmanagement.KontouwasapostdoctoralresearchassociateattheTransportationandHydrogenSystemsCenteroftheNationalRenewableEnergyLaboratoryandtheCityandRegionalPlanningDepartmentofthe

UniversityofNorthCarolinaatChapelHill.

AlexanderYoshizumileadstheSystemsPlanning&AnalysisprogramattheInstituteforTransportationResearchandEducation(ITRE)atNCStateUniversity,whereheoverseestheTriangleRegionalModel:thetraveldemandmodelservingNorthCarolina’sTriangleregion.HealsoservesasExecutiveDirectoroftheAppliedDataResearchInstitute,a

nonprofitorganizationthatappliesdatascienceandsystemsmodelingtoaddress

complex,real-worldchallenges.Hisexpertisespanstransportation,energy,andland

changesystemsmodeling.Hehasledandcontributedtoawiderangeofmodeling

efforts,includingtraveldemandforecasting,process-basedlandchange,regionalgrowthallocation,agent-basedevacuationtravel,andenergysystemsoperations.

ImpactofElectricTariffsonMedium-andHeavy-DutyVehicleChargingCostsandLoadsii

AboutRFF

ResourcesfortheFuture(RFF)isanindependent,nonprofitresearchinstitutionin

Washington,DC.Itsmissionistoimproveenvironmental,energy,andnaturalresource

decisionsthroughimpartialeconomicresearchandpolicyengagement.RFFiscommittedtobeingthemostwidelytrustedsourceofresearchinsightsandpolicysolutionsleadingtoahealthyenvironmentandathrivingeconomy.

Workingpapersareresearchmaterialscirculatedbytheirauthorsforpurposesof

informationanddiscussion.Theyhavenotnecessarilyundergoneformalpeerreview.Theviewsexpressedherearethoseoftheindividualauthorsandmaydifferfromthoseof

otherRFFexperts,itsofficers,oritsdirectors.

AboutIPI

TheInstituteforPolicyIntegrityisanon-partisanthinktankhousedattheNewYorkUniversitySchoolofLawdedicatedtoimprovingthequalityofgovernmentaldecisionmaking.PolicyIntegrityproducesoriginalscholarlyresearchinthefieldsofeconomics,law,andregulatorypolicy.Italsoadvocatesforreformbeforecourts,legislatures,andexecutiveagencies.Itsprimaryareaoffocusisenvironmentalandenergypolicy.

Acknowledgements

WewouldliketothankKarenPalmer,BenMandel,SamWands,MeredithAlexanderandCALSTARTfortheirinput,feedbackandsupportofthisproject.Allerrorsareourown.

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ResourcesfortheFutureiii

Abstract

Thispaperemploysaneconomics-engineeringmodeltosimulatetheimpactofvarious

electrictariffstructuresandratelevelsonthechargingeconomicsofsixhypothetical

medium-andheavy-dutyvehiclefleets,includingtheirtotalbillsandpeakdemand

withoutmanagedchargingaswellastheiropportunitytosavemoneyandlowertheir

peakdemandbymanagingtheircharging.Itusesrealfleetdatafromasetoffossil-fueledfleetsasthebasisformodelingthedutycycleofhypotheticalelectricfleets;employs

heuristicsforhowanoperatorwouldrespondtoapricesignal;modelschargingbehaviorinthecontextofseveralthousandratesdescribedintheNationalRenewableEnergy

Laboratory’sUtilityRateDatabase;compareschargingbehaviordependingontariff

features,includingrelianceondemand-basedversusvolumetricdeterminants,andthe

extenttowhichtheyaretime-variant;andevaluatesthepotentialforcostsavings,peakdemandmitigation,andthealignmentbetweenthoseoutcomes.Wefindthatmanaged

chargingcanprovidesubstantialcostsavingsforelectricvehiclefleetswhilealleviatingpeakdemandpressuresonthegrid.Amongthetariffstructuresanalyzed,thosewith

time-of-usedemandandvolumetriccomponentsdeliverthehighestcost-saving

opportunitiescomparedwithothertariffs,especiallyforfleetswithadaptablecharging

schedulesandsignificantdailymileagerequirements.Incontrast,tariffswithflat

volumetricrates,orthatdonotincludeademandcomponent,maybestraightforwardbutofferlittleincentiveforcostoptimizationthroughloadshifting.

ImpactofElectricTariffsonMedium-andHeavy-DutyVehicleChargingCostsandLoadsiv

Contents

1.Introduction1

2.ElectricTariffsforCommercialCustomers3

3.Methodology5

4.Data13

4.1.FleetCharacteristics13

4.2.ChargingCharacteristics14

4.3.TariffData15

5.Results18

5.1.Tariffswithnodemandcharges23

5.2.Tariffswithflatdemandcharges25

5.3.TariffswithTOUdemand26

5.4.Tariffswithflatvolumetricrates28

5.5.TariffswithTOUvolumetricrates29

6.DiscussionandConclusions31

References33

AppendixA:ElectricTariffsBasics37

AppendixB:FleetData39

AppendixC:FleetChargingCharacteristics41

AppendixD:TariffSelectionDetails42

AppendixE:TariffTypes44

AppendixF:ClusteringMethodology44

AppendixG:ChargingScheduleOptimizationExample45

AppendixH:AlgorithmforOptimizingtheChargingScheduleunder

TDTVandTDFV46

ResourcesfortheFuture1

1.Introduction

Medium-andheavy-dutyvehicles(MHDVs;i.e.,trucksandbuses)produce23percentofthetransportationsector’sgreenhousegas(GHG)emissionsandoverhalfofall

localairemissions;however,theyrepresentonlyabout10percentofthevehiclemilestraveled(EPA2025;AmericanLungAssociation2022;BTS,n.d.,2020data).

Electrificationofthesevehiclescouldthushelpmitigatepollutionexternalities.The

technologytoelectrifythesevehicleshasbeencommercialized,andexistingrangescurrentlyallowformanyexistingdieselfleetstosuccessfullyconducttheiroperationsusingelectricvehicles.

Thebenefitsofvehicleelectrificationextendbeyondemissionsreductions;besides

providingthedriverwithimprovedcomfort,health,anddrivingexperience,electric

vehicleshaveoftenbeentoutedfortheirlower-costrefueling.Becauseelectrictrucksandbusescostsignificantlymoreupfrontthantheirdieselcounterparts,

1

and

switchingtothemwillrequirelearningandimposetransitioncostsonthefleet(Spilleretal.2023b;Danielisetal.2025),rapidfleetadoptionwillrequireunlocking

opportunitiesforoperationalsavingsthroughfavorablefuelingcosts(KonstantinouandGkritza2023;HensherandWei2024).

Thoughkeepingoperationalcostslowisessentialtoadvancetruckandbus

electrification,itisalsoimportanttomitigatethecoststhatthesevehiclesplaceon

thesystem.Giventhelargesizeofthesevehicles’batteries,theirindividualand

aggregategridimpactcouldbesignificant(NationalGridetal.2022).Thus,managingtheirchargingwillbenecessarytoensurethatthetransitiontoelectrictrucksand

busesisdoneinasociallycost-effectivemanner.

Thechallengethereforeistolowerthecostofchargingforelectric-vehiclecustomerswhilestillincentivizingsociallyoptimalchargingbehavior.Theelectrictariff,apricescheduleestablishedbyelectricutilitieswithregulatoryoversightthatsetsthepricesleviedoncustomersfortheiruseoftheelectricgridandconsumptionofpower,hasimplicationsforbothsidesofthiscoin.

2

Itisakeydriverofcustomers’costof

chargingandtheirchargingbehavior.Ifstructuredcarefully,electrictariffscan

providetheopportunityforfleetoperatorstomanagecharginginawaythatreducesboththefleet’selectricbill(incomparisonwithwhatitwouldbeiffleetoperatorsdidnotintentionallymanagetheircharging)andtheimpactonthegrid.

3

Essentially,the

1SeeSpiller(2023)forananalysisofthecostdifferentialbetweenelectricanddieseltrucks.

2Insomestates,thepriceoftheelectriccommoditydeliveredbyelectricutilitiesmaybesetcompetitively,althoughthepricingfortheuseoftheutility’sgridisstillsetbytariff.See

generallyDormadyetal(2025).

3Notably,chargingmanagementcouldalsohaveimportantbenefitstoemissions,byshiftingdemandsintocleanerhours(Luetal2023);however,estimatingtheenvironmentalimpactsofthesetariffsisbeyondthescopeofthisstudy.

ImpactofElectricTariffsonMedium-andHeavy-DutyVehicleChargingCostsandLoads2

abilitytomanagechargingcanprovidelargesocialandprivatebenefits,andelectrictariffscancreatethepriceincentivetoenablethis.

Inthispaper,weexploretheextenttowhichexistingelectrictariffscansupporttheachievementofbothgoals.Becausetariffstructuresandlevelsvarybygeographic

locationandeachfleethasitsownoperationalneeds,understandingtheabilityof

tariffstoreducecustomers’peakdemandovervariousmeasurementperiodswhile

reducingtheoperationalcostsofadoptionrequiresanexplorationofbothavarietyoftariffsandavarietyoffleets.Tothatend,wesimulatetheeffectofelectrictariffsoncustomerbillsanddemandlevels,byanalyzingtheimpactofthousandsofcurrent

electrictariffsacrossthecountryonfourdifferentfleettypes—schoolbuses,transitbuses,refusetrucks,anddeliveryvehicles—givenanassumedfleetsizeof50

vehicles.

Usingtelematicsdatafromexistingfossil-fueled(FF)fleetsacrossthecountry,we

firstsimulateunmanagedchargingloads.

4

Inthissimulation,eachtimeafleetreturnstoitsdepot,itpromptlychargesallvehiclessimultaneouslyuntilfullycharged.The

magnitudesandpatternsoftheseunmanagedchargingloadsdependonthevehicles’andcharginginfrastructure’scharacteristicsandoperations.Giventheseunmanagedchargingloads,wecalculatethecostthefleetwouldfaceunderavarietyofelectrictariffs,assumingnoresponsivenesstoprice.

Wethensimulateamanagedchargingscenarioinwhichfleetsadjusttheirpatternsofcharging—withtheirflexibilitytomakesuchadjustmentsbeinglimitedbyvehicle

milestraveled(VMT)needsanddwellperiodsrevealedbythetelematicsdata—tominimizetheirelectricbillsunderthesamesetofelectrictariffs.Thesemanagedchargingloads,andtheresultingbills,thusrepresentapproximatelywhatcouldbeachievedthroughpricingincentivesintermsofreducedpeaksandelectricbill

savings.

Thepaperproceedsasfollows:InSection2,weprovidemoredetailonelectrictariffsforfleets;inSection3,wedescribethemethodology;andinSection4,wepresentourdata.WediscussourresultsinSection5,includingtheimpactsonbothloadsand

electricbills.WeconcludeinSection6withadiscussionofourfindingsandsuggestionsforfutureresearch.

4Mostofthefossil-fueledfleetsinoursamplearediesel-based,thoughthereisonecompressednaturalgasfleet.

ResourcesfortheFuture3

2.ElectricTariffsforCommercialCustomers

InmuchoftheUnitedStates,largecommercialandindustrialcustomers,whichare

generallycommercialentitieswithfairlyhigh-capacityelectricityservice,areoften

subjecttotariffsthathavemultiplebillingdeterminants.Theseincludebothdemand-basedcomponents,whichdependonthecustomer’speakdemand,whetheroveralloratspecifictimes,andvolumetriccomponents,whichdependontotalenergy

consumption(seeNARUC2016,100).Demandchargesessentiallylevyfeeson

customersfortheirmaximumdemandorconsumptionduringoneormore

prespecifiedtimeintervals,suchasanhouror15minutes.

5

Thesedemandchargesaregenerallyfixedthroughoutthemonth,whichmeansthatwhetherthecustomerhitsapeakdemandonlyonceorsustainsthatpeakdemandconsistently,theywillbe

chargedthesameamount.

6

(Foramorein-depthdescriptionofdemandandelectricitypricesintheframeworkofutilitycostrecovery,seeAppendixA).

Optimizingdemandinthefaceofdifferentpricesignalsemergingfromdifferent

billingdeterminantsmaybechallengingforsomecustomers(Stikvoortetal.2024),thoughtoolssuchasmanagedchargingsoftwareexisttohelpfleetsmanagetheirdemand(see,e.g.,DOE,n.d.).

Demandchargeshaveprovenhighlyproblematicforcommercialelectricvehicle(EV)-chargingcustomers,particularlypublicchargingstations(Leeetal.2020;BorlaugandBennett2022).Becausetheyarecommercialcustomerswithhigh-capacityelectricityservice,publicEVchargingstationsaregenerallysubjectbydefaulttodemand

charges(Muratorietal.2019).Formostcommercialorindustrialcustomerswithanygivenhighlevelofpeakdemand,theexpectationwouldbethattheywouldalsohaveasimilarlyhighleveloftotalconsumption—thehighpeakdemandwouldbesustained,oratleastfrequent,andnotallthatfarofffromtheirtypicaldemand.Butthisisnot

trueforpublicEVchargingstations—theirpeakdemandmightbequiteanomalous,

bearinglittleresemblancetoaverageenergyconsumptionfortheirongoing

operations(Tongetal.2021).Ifseveralchargersareinusesimultaneously,justonce,ademandchargemightgetsetatalevelcomparabletothatofasizablecommercial

facility—butafterthatonegoodday,theEVchargersmayreceivelittleuse.TheresultisthatapublicEVchargingstationwithlowutilizationmightincurelectricbillsthat

arecomparabletothatofasizablecommercialfacility,whileinfactchargingonlyasmallnumberofcars(Muratorietal.2019).

ThisisanentirelypredictableresultduringthetransitiontoEVs—lowutilizationisinevitablythenormearlyinthetransition.Thechallengeisexacerbatedbythefact

5Thesetimeintervalsaredeterminedbytheutility,withregulatoryoversight,basedonanumberoffactors.

6Ifthecustomerisalsosubjecttovolumetriccharges,thenasustainedhighlevelofconsumptionwouldbemoreexpensive.

ImpactofElectricTariffsonMedium-andHeavy-DutyVehicleChargingCostsandLoads4

thattobesuccessful,publicchargingstationsmust,forthemostpart,beavailableondemandtochargeEVsatapricethatindividualcarownerscantolerate,whenever

EVsinneedofachargehappentoshowup.Thehighutilitycostsassociatedwith

demandcomparabletothatofasizablecommercialfacilitycouldnotpossiblybe

passedontoaverysmallnumberofcar-chargingcustomers;iftheywere,the

resultingcostofchargingEVscouldbeordersofmagnitudehigherthanthecostoffillingupgas-fueledcars.Inshort,withoutsomekindofmitigation,demandchargescouldmakepublicchargerswithlowutilizationimpossibleforcommercialentitiestobuildoroperate,posinganinsurmountablebarriertoearlydeploymentofpublic

charging(ordeploymentofpublicchargersinremotelocations,wherechargerusagemayalwaysbeinfrequent).

7

Peoplewhoownelectricvehiclesandchargethemusingtheirresidentialelectricity

servicegenerallydonotencounterthisissueontheirhomeelectricservice,astheydonottypicallypaydemand-basedratesatall.Andtime-of-use(TOU)volumetrictariffshaveprovenhighlyeffectiveinhelpingsuchresidentialcustomerssavemoneyon

chargingrelativetoanon-time-varianttariff,whilealsomitigatingtheimpactof

incrementalelectricitydemandarisingfromhomecharging(see,e.g.,Qiuetal.2022).Buttheabilitytochargequicklywhileonlongtrips—inamannerthatcustomers

perceiveasroughlycomparabletorefuelinganinternalcombustionenginevehicle—iswidelyunderstoodasessentialforelectriccarstocompetewithgascars.Because

commercialfastchargingofcarswasoneoftheearliestcommercialcharging

applicationstobegintoscaleup,theincompatibilitybetweendemandchargesand

early-stageproliferationofpublicfastcharginghasbeenwidelyunderstoodasa

fundamentalmismatchbetweencommercialtariffsandvehicleelectrification.In

response,advocatesforvehicleelectrificationhaveworkedtodevelop,andsometimesmandate,alternativecommercialelectrictariffstructuresforuseonatemporaryor

permanentbasis(see,e.g.,AllianceforTransportationElectrification2022;NARUC

2022).InNewYork,thiseffortculminatedinthepassageofastatutethatrequiredtheestablishmentofalternativestotraditionaldemand-basedtariffstructurestofacilitatefastercharging.

8

However,whiledemandchargesmaybeademonstrablypoorfitforanimportantearlycommercialEV-chargingusecase,notallcommercialchargingresemblestheearly

public-chargingusecase.Infact,theremaybesomeEV-chargingusecasesforwhichconventionalcommercialtariffs,includingthosethatresultinbillsthataredriven

7Mitigationcouldoccureitherthroughchangesinthetariffapplicabletothepublicchargingstationsorthroughactiontakenbytheoperator,suchasinvestmentinbatterystorageto

smoothoutpeakdemand.

8Thelegislationcanbefoundat

/pdf/bills/2021/S3929.

Anamendedversionofthatlaw(see

/pdf/bills/2021/A8797

)

directedtheutilityregulatortoundertakeaprocesstoexaminearangeofoptions,including—withoutlimitation—alternativestotraditionaldemand-basedtariffstructures;theresulting

proceedingremainsongoingattheNewYorkPublicServiceCommission.Formoreinformationontheproceeding,see

/public/MatterManagement/CaseMaster.aspx?Mattercaseno

=22-E-0236.

ResourcesfortheFuture5

primarilybydemand-basedbillingdeterminants,mightbeareasonablygoodfit.

Consider,forexample,whetherthereareEV-chargingusecasesthatmaystrongly

resemblethecommercialandindustrialfacilitiesthathavebeenabletoflourishunderconventionalelectrictariffs.CancommercialEV-chargingloadseverhavehigh

consumptionthatisreasonablyproportionaltotheirhighdemand?Arethere

commercialEVchargingentitiesthathavethecapabilityofmanagingthetimingoftheircharginganditsresultingloadshape,muchasothercommercialandindustrialcustomersmanagetheirelectricloadtoavoidthehighestpricesandoptimizetheirenergyprocurement?

Thesetypesofquestionshavebeenexploredinlargepartforelectrictransitbuses

andtheabilityofthesefleetstoreducetheirelectricbillsinresponsetotime-of-useratesanddemandcharges.Withintheengineeringliterature,researchhas

demonstratedthattransitbusescouldoptimizetheirchargingpatternsinresponsetotime-of-userates(Qinetal.2016;Heetal.2022,whofocusonon-routefastcharging;Zhanetal.2025;Xiaoetal.2024)anddemandcharges(Qinetal.2016;Heetal.2020;Al-Hanahi2022;Xiaoetal.2024)toachievebillsavings.Galloetal.(2014)calculate

thebillimpactsforelectrictransitbusesunderademandchargetariffandcompareitwithalternativetariffs,suchasvolumetrictime-of-use,butdonotsimulateanypriceresponsiveness.

9

Accountingforpriceresponsivenessiskey,however,asQinetal.

(2016)findthatbyoptimizingcharginginresponsetodemandcharges,afleetoffiveelectricbusescouldsaveover$160,000inelectricitycostsovera12-yearvehicle

lifetime.Whilethereisevidencefromtheliteraturethatelectrictransitbusescan

benefitfromtime-of-useratesanddemandcharges,thesepapersarelimitedinthattheylookprimarilyattransitbusfleetsandgenerallyjustoneortwospecifictariffs.

Thebroaderquestionofhowtariffstructureandpricedifferencescanaffectmanagedchargingpatternsacrossavarietyoffleettypesisstillunanswered.

Thus,ourreviewoftheliteraturesuggeststhattheanswerstothesequestionsare,forthemostpart,unknown.Solutionstothedemandchargeproblemapplicabletothe

low-utilizationpublic-chargingusecasehavesometimesbeenadoptedasgenerallyapplicablecommercialchargingtariffsolutions(seeSilverman2023).Yetnorigorousanalysishasconsideredhowavarietyofcommercial-chargingusecasesmight

interactwiththetypesofelectricratesthatwouldbeapplicabletothemacrosstheUnitedStates.Weseektofillthatgapwiththispaper.

3.Methodology

Inthispaper,weuseaneconomics-engineeringmodeltosimulatetheimpactofvarioustariffstructuresandratelevelsonelectricbills(underbothmanagedand

9Similarly,Phadkeetal.(2019)estimatethecostofchargingaheavy-dutytruckunderdemandchargesandtime-of-useratesbutdonotsimulateresponsiveness.Theyfindthattime-of-userateswouldresultincheaperchargingrates,thoughitisunclearwhetherincorporatingfleet

responsivenesstopricingwouldchangethisresult.

ImpactofElectricTariffsonMedium-andHeavy-DutyVehicleChargingCostsandLoads6

unmanagedchargingloads),maximumloads,andmanagedchargingforfourdifferenttypesoffleets:schoolbuses,transitbuses,refusetrucks,andclass6deliveryvehicles.Theidealapproachtoestimatingthisimpactwouldbetohaveacontrolled

experimentinwhichweimposearangeoftariffsonseveralfleetsandobservehow

thesetariffsaffectouroutcomesofinterest.However,thisidealexperimentis

impossible,asanyfleetwouldbesubjecttoalimitednumberofdifferenttariffs(thatis,thosethatareavailablefromtheutilitythatservesthefleet’spremises);thismeansthatconductingthistypeofexperimentatalargescale,usingtariffsfromacrossthecountry,wouldbeinfeasible.Furthermore,adoptionhasbeenslow,withheavy-dutyelectricvehiclesnotsurpassing1percentof