ISSN1831-9424

CLEANENERGYTECHNOLOGYOBSERVATORY

2024

SmartThermalNetworksintheEuropeanUnion

STATUSREPORTONTECHNOLOGY

DEVELOPMENT,TRENDS,VALUECHAINS&MARKETS

EUR40080

ThisdocumentisapublicationbytheJointResearchCentre(JRC),theEuropeanCommission’sscienceandknowledgeservice.Itaimstoprovideevidence-basedscientificsupporttotheEuropeanpolicymakingprocess.ThecontentsofthispublicationdonotnecessarilyreflectthepositionoropinionoftheEuropeanCommission.NeithertheEuropeanCommissionnoranypersonactingonbehalfoftheCommissionisresponsiblefortheusethatmightbemadeofthispublication.ForinformationonthemethodologyandqualityunderlyingthedatausedinthispublicationforwhichthesourceisneitherEurostatnorotherCommissionservices,usersshouldcontactthereferencedsource.ThedesignationsemployedandthepresentationofmaterialonthemapsdonotimplytheexpressionofanyopinionwhatsoeveronthepartoftheEuropeanUnionconcerningthelegalstatusofanycountry,territory,cityorareaorofitsauthorities,orconcerningthedelimitationofitsfrontiersorboundaries.

Contactinformation

Name:JonathanVolt

Email:JRC-PTT-HEATCOOL@ec.europa.eu

EUScienceHub

https://joint-research-centre.ec.europa.eu

JRC139334

EUR40080

PDFISBN978-92-68-21000-0ISSN1831-9424doi:10.2760/4896278KJ-01-24-084-EN-N

Luxembourg:PublicationsOfficeoftheEuropeanUnion,2024

?EuropeanUnion,2024

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.

Thismeansthatreuseisallowedprovidedappropriatecreditisgivenandanychangesareindicated.

TheEuropeanUniondoesnotownthecopyrightinrelationtothefollowingelements:(1)Frontpagephoto?PavloGlazkov-

,(2)Figure1comesfromLundetal.2014.4thGenerationDistrictHeating(4GDH):Integratingsmartthermalgridsintofuturesustainableenergysystems,(3)Figure4comesfromIRENA,2020.Innovationoutlook:Thermalenergystorage.

Howtocitethisreport:EuropeanCommission,JointResearchCentre,Volt,J.,RocaReina,J.C.,Toleikyte,A.,Mountraki,A.,Letout,S.,

Wegener,M.,andBlack,C.,CleanEnergyTechnologyObservatory:SmartThermalNetworksintheEuropeanUnion-2024StatusReportonTechnologyDevelopment,Trends,ValueChainsandMarkets,PublicationsOfficeoftheEuropeanUnion,Luxembourg,2024,

https://data.europa.eu/doi/10.2760/4896278,

JRC139334

1

Contents

Abstract 2

ForewordontheCleanEnergyTechnologyObservatory 3

Acknowledgements 4

ExecutiveSummary 5

1.Introduction 8

Smartthermalnetworktrendsinfocus 12

2.TechnologyStateoftheartandfuturedevelopmentsandtrends 17

2.1Technologyreadinesslevel 18

2.2InstalledenergyCapacity,Generation/Production 19

2.3TechnologyCost-PresentandPotentialFutureTrends 22

2.4PublicR&Ifunding 23

2.5Patentingtrends 24

2.6Valuechainanalysis 26

3.EUpositionandGlobalcompetitiveness 28

3.1Global&EUmarketleaders(Marketshare) 28

3.2Trade(Import/export)andtradebalance 29

Conclusions 32

References 34

Listofabbreviationsanddefinitions 37

Listofboxes 38

Listoffigures 39

Listoftables 40

Annex3EnergySystemModelsandScenarios:POTEnCIAandPOLES-JRC 41

AN3.1POTEnCIAModel 41

AN3.1.1ModelOverview 41

AN3.1.2POTEnCIACETO2024Scenario 42

2

Abstract

Thisreportispartofthe2024CleanEnergyTechnologyObservatoryseriesandisfocusingonsmartthermalnetworkswithintheEuropeanUnion.Itprovidesanoverviewofthecurrentstatus,emergingtrends,andthepotentialofthissectorintegrationtechnology.Smartthermalnetworksrepresentasubstantialopportunityforurbanareas,functioningwithincreasedefficiencyandsmartercontrolatlowerflowtemperatures.Thisenablestheintroductionofmorerenewableenergysourcesandwasteheat,whilealsoenhancingtheflexibilityofthesystem.Asaresult,smartthermalnetworkscanserveasversatileassets,providingbalancingservicestothewiderenergyinfrastructure.

AnincreasingnumberofdistrictheatingandcoolingsystemswithintheEuropeanUnionareevolvingintosmartthermalnetworks.Manycitiesarechannellinginvestmentsintotheexpansionandmodernisationoftheircurrentinfrastructurestomeetanticipatedfutureenergydemands,whichareincreasinglydependentonvariablerenewableenergysources,likesolarandwindpower.Smartthermalnetworksincorporatearangeoftechnologies,themajorityofwhicharetechnologicallyadvanced,suchasintelligentcontrolsystemswithsensors,utilisationofwasteheat,high-efficiencycogeneration,large-scaleheatpumps,andthermalenergystoragesystems.Oneofthemostpromisingfrontiersforinnovationliesindigitalisation,whichenablesthesmoothintegrationandmanagementofenergyflows.Bypromotingintelligentcontrolanddataexchangethroughoutthesystem,smartthermalnetworkscancontroltheiroperationsforoptimalperformanceintheshortandmediumterm.Asaglobalfrontrunnerinthisarena,Europeiswell-equippedtospearheadtheshifttowardssmartthermalnetworks,exemplifyingtheirimportancewithintheframeworkofcarbonneutralandsmartcities.

3

ForewordontheCleanEnergyTechnologyObservatory

TheEuropeanCommissionsetuptheCleanEnergyTechnologyObservatory(CETO)in2022tohelpaddressthecomplexandmulti-facetedcharacterofthetransitiontoaclimate-neutralsocietyinEurope.TheEU’sambitiousenergyandclimatepoliciescreateanecessitytotackletherelatedchallengesinacomprehensivemanner,recognisingtheimportantroleforadvancedtechnologiesandinnovationintheprocess.

CETOisajointinitiativeoftheEuropeanCommissionJointResearchCentre(JRC),whichrunstheobservatory,andDirectorate-GeneralsResearchandInnovation(RTD)andEnergy(ENER)onthepolicyside.Itsoverallobjectivesareto:

-monitortheEUresearchandinnovationactivitiesoncleanenergytechnologiesneededforthedeliveryoftheEuropeanGreenDeal;

-assessthecompetitivenessoftheEUcleanenergysectoranditspositioningintheglobalenergymarket;

-buildonexistingCommissionstudies,relevantinformationandknowledgeinCommissionservicesandagencies,andtheLowCarbonEnergyObservatory(2015-2020);

-communicatefindingsbypublishingreportsontheStrategicEnergyTechnologyPlan(SET-Plan)SETISonlineplatform.1

CETOprovidesarepositoryoftechno-andsocio-economicdataonthemostrelevanttechnologiesandtheirintegrationintheenergysystem.Ittargetsinparticularthestatusandoutlookforinnovativesolutionsaswellasthesustainablemarketuptakeofbothmatureandinventivetechnologies.TheprojectservesasaprimarysourceofdatafortheCommission’sannualprogressreportsoncompetitivenessofcleanenergytechnologies.

ItalsosupportstheimplementationofanddevelopmentofEUresearchandinnovationpolicy.2Theobservatoryproducesaseriesofannualreportsaddressingthefollowingtopics:

Cleanenergytechnologystatus,valuechainsandmarkets:coveringadvancedbiofuels,batteries,bioenergy,carboncaptureutilisationandstorage,concentratedsolarpowerandheat,geothermalheatandpower,heatpumps,hydropowerandpumpedhydropowerstorage,novelelectricityandheatstoragetechnologies,oceanenergy,photovoltaics,renewablefuelsofnon-biologicalorigin,renewablehydrogen,solarfuelsandwind;

Cleanenergytechnologysystemintegration:building-relatedtechnologies,digitalinfrastructureforsmart

energysystems,industrialanddistrictheatandcoolingmanagement,standalonesystems,transmissionanddistributiontechnologies,smartcitiesandinnovativeenergycarriersandsupplyfortransport;

Foresightanalysisforfuturecleanenergytechnologiesusingweaksignalanalysis;

-cleanenergyoutlooks:analysisandcriticalreview;

-systemmodellingforcleanenergytechnologyscenarios;

-overallstrategicanalysisofcleanenergytechnologysector.

MoredetailsareavailableontheCETOwebpages.3

(1)

https://setis.ec.europa.eu/what-set-plan_en

.

(2)

https://energy.ec.europa.eu/topics/research-and-technology/clean-energy-competitiveness_en

.

(3)

https://setis.ec.europa.eu/publications/clean-energy-technology-observatory-ceto_en

.

4

Acknowledgements

Theauthorsextendtheirsincereappreciationtotheexternalexpertsfortheirinvaluableandinsightfulcontributionsandfeedback,including:

●OddgeirGudmundsson,AytajImanovaKinner&JanEricThorsenfromDanfoss

●AksanaKrasatsenka&GabrielePescerepresentingEuroheat&PowerandtheDHC+Platform

●LarsHummelmose&MortenDuedahlfromtheDanishBoardofDistrictHeating(DBDH)

AspecialthankyoualsototheEuropeanCommissioncolleaguesGiuliaSerra(ENER),EricLecomte(ENER),ThomasSchleker(RTD),NigelTaylor(JRC),AndreasSchmitz(JRC),LorcanLyons(JRC),andGeorgThoma?en(JRC)fortheirfeedback,guidanceandsupport.

TheauthorswouldliketothanktheJRC.C.6POTEnCIAenergysystemmodellingteamforprovidingenergyscenarios:Jaxa-Rozen,M.,SalvucciR.,Neuwahl,F.,R.,Sikora,P.,andRózsai,M.

Authors:JonathanVolt,JuanCarlosRocaReina,AgneToleikyte,AikateriniMountraki,SimonLetout,MoritzWegenerandCatrionaBlack

5

ExecutiveSummary

ThisreportispartoftheCleanEnergyTechnologyObservatory(CETO)2024series,featuringtechnologiesandtheirintegrationandcontributiontoacleanenergysystem.Itdescribeshowsmartthermalnetworks,operatingmoreintelligently,efficientlyandonlowertemperaturesthanconventionaldistrictheatingsystems,canenabletheintegrationofahighershareofrenewableenergysourcesandbecomeaversatileassetforthewiderenergysystembyprovidingflexibilityservices.Thisreportsummarisesthestatus,trendsandpotentialofsmartthermalnetworksasasectorintegrationtechnology.

Policycontext

Inanefforttocutcarbonemissionsandbuildforacarbon-neutralfuture,theEuropeanUnion(EU)strivestodecarboniseitsheatingandcoolingsystems,whichconstitutearoundhalfoftheregionsenergyconsumption.TheEUhasidentifieddistrictheatingandcooling(DHC)networksasanimportantelementintheprocessofimprovingenergyefficiencyandreducinggreenhousegasemissionsinurbanareas.

EUhasthereforeenactedanumberofdirectives,strategiesandsupportschemes.Policyinstruments,suchastheEnergyEfficiencyDirectiveandtheRenewableEnergyDirective,mandateMemberStatestocarryoutheatingandcoolingassessmentsandrequireacertainincreaseofrenewablesintotheirthermalsystems.TheEuropeanPerformanceofBuildingsDirectivesupportsefficientbuildingstandardswhichgohandinhandwithlowerflowtemperatures.Financialbackingisprovided,forexample,throughtheCohesionPolicyFundsandInvestEUtosupportDHCexpansionsandimprovements.Strategicefforts,includingtheEuropeanStrategicEnergyTechnologyPlanandtheEuropeanPartnershipforCleanEnergyTransition,alsopushforrenewableenergyinDHC.Inparallel,thereareanumberofeffortsboostdigitalisationandenergysmartness,forexamplethroughthenewstrategy“EuropeFitfortheDigitalAge”.TheEUisalsopursuingtohave100climate-neutralandsmartcities4by2030,inwhichsmartthermalnetworkswillplayakeyroleforanumberofcities.

DistrictheatingandcoolingintheEU

Therearearound19000districtheatingnetworksinEurope5.Asof2022,thecollectiveinstalledcapacityofthedistrictheatingsystemsacrossEuropeamountstoapproximately333gigawattsthermal(Euroheat&Power,2024).Districtheating,despitesupplyingjust13%ofthisdemand,playsapivotalroleintheenergystrategiesofcountriesthatexcelinreducingcarbonemissions,notablytheNordics.IncertainEUMemberStates,it’sintegraltothevisionofachievingaflexible,efficient,anddecarbonisedenergysystem,whereasitisscarcelypresentinothers.Forinstance,districtheatingsatisfiesasubstantialportionoftheheatingneedsinDenmark(66%)andFinland(45%)(Euroheat&Power,2024).Moreover,Germany,Poland,andtheNordiccountriesaccountedfor68%oftheEU’stotaldistrictheatingconsumptionin2018(Eurostat,2022).Incontrast,theadoptionintheBeneluxcountriesandmostofSouthernEuroperemainssofarlimited.

DistrictcoolingismuchlesscommoninEU,withatotalinstalledcapacityof7.74gigawattsandaround200installations(Pezzutto,etal.,2022).DistrictcoolingisexperiencinggradualadoptionandexpansionacrossvariousregionsinEuropebeyondtheleadingcountriesofSwedenandFrance,whichcurrentlyareaccountingforaroundtwo-thirdsofthetotaldistrictcoolingsuppliesintheEU(Euroheat&Power,2024).Districtcoolingisexpectedtoplayamoreprominentroleinthefuture.

Theroleofsmartthermalnetworks

Thetermsmartthermalnetworkreferstoanefficientheatinginfrastructure,distributingheatingandcoolingtomultiplepointsofdeliverywithinadistrictoracity.Asmartthermalnetworkischaracterisedbytheuseofintelligentcontroltechnologiesandstrategiestooptimisetheoperation.Smartthermalnetworkfurtherstrivesforoperationwithlowdistributiontemperaturesformaximizingthepotentialforenergyefficientintegrationofalternativeenergysources.Smartthermalnetworksaregenerallycharacterisedbyahighercomplexityintermsofnumeroussupplypointswhichenablesmoreflexibilityinthesystemoperation.Inparticular,combinedwithlarge-scalethermalenergystorage,theycanprovideenormousflexibilityandoptimisationpotentialtothewiderenergysystem.

Smartthermalnetworksenableinvaluablesector-couplingsynergies.Firstly,theinfrastructureenablesrecuperationofwasteheat.Forexample,thethermalnetworkcanrecoverwasteheatfromindustrialprocessesordatacentres,butalsoprovidethemwithcoolingservices,awin-winexchange.Secondly,withpower-to-heattechnologies(especiallycombinedheatandpower,largeheatpumpsandelectricboilers),excesselectricitycan

(4)

https://research-and-innovation.ec.europa.eu/funding/funding-opportunities/funding-programmes-and-open-calls/horizon-

europe/eu-missions-horizon-europe/climate-neutral-and-smart-cities_en

(5)Includingalsonon-EUcountriessuchasNorway,SwitzerlandandtheUK.

6

bestoredasheatinthethermalnetwork,forexampleintimesofanabundanceofsunorwind.Withthesamelogic,whenthereisashortageofelectricity,productionfromcombinedheatandpowercanbesteeredtowardsproducingmoreelectricitywhilethethermalnetworkusesthestoredheat.

Technologystateofartandfuturestrends

Mostindividualcomponentsofsmartthermalnetworkshavereachedahighleveloftechnologicalreadiness(i.e.TRLof8or9),includingsensorsandintelligentcontrolsystems,high-efficientcogeneration,largeheatpumpsandthermalenergystoragetechnologies.

However,theintegratedconceptofsmartthermalnetworkshasconsiderableinnovationpotentialleft.Therearelocalnetworksthathavebeenincrementallybuilttowardsbecomingsmartthermalnetworks,althoughtheystillhavequitesomepathtogobeforebecomingtrulysmart.Withtheintegrationofmachinelearning/AItechnologies,smartthermalnetworkshavebecomemuchmoreintelligentandabletomanagemorecomplexsystems.Aconsiderableinnovationpotentiallieswiththedigitalandcontrolelementsofthethermalnetworksratherthanwiththephysicalnetworksthemselves.

Anotherpromisingtrendistoutiliseathermalenergystorageasavirtualpowerbatterytosupportpowergrids.Thethermalenergystorageischargedwhenthereisanabundanceofrenewableenergyanddischargestothedistrictheatingnetworkwhenthereisascarcityofrenewables,thusloweringthepowerdemand.Dependingonthesizeandnumberofcyclesperyearthisapproachhasthepotentialtosignificantlyoutperformanypowerbattery,bothintermsofcapacityand“power-to-power”efficiency.

TheEUpositionandglobalcompetiveness

TheEUisagloballeaderwhenitcomestosmartthermalnetworks,withmorenetworksoperatingatlowertemperaturesandwithahighershareofrenewablesinthesystems.TheUnitedStatesandmostpartsofChinadonothavethesametrackrecordofestablishingdistrictheating(andcooling)systems.Whilemostproductionandinstallationislocalwhenitcomestosmartthermalnetworks(exceptsoftwareanddigitalapplications),Europehastheopportunitytospearheadthetransitiontosmartthermalnetworksandshowcasetheirvalueinthelow-carbontransition.Thisis,forexample,evidentinEU’sroleasaglobalexporterofheat-exchangeunits.In2023,theamountofheat-exchangeunitsexportedfromtheEUtoanon-EUcountryincreasedby11%comparedto2022,reachingalmostEUR2.4billion.

Table1presentsaSWOTanalysis,illustratingthecentralstrengths,weaknesses,opportunities,andthreatsforthissector-integratingtechnologyintheEuropeancontext.

7

Table1:SWOTtableofSmartThermalNetworksintheEU

Strengths

Flexibilityandstorage:

●Flexibility:smartthermalnetworkscanprovideflexibilitytothewiderenergysystem

●Inexpensivestorage:theintegrationofthermalenergystoragescanprovideaninexpensiveenergystoragesolutiontothewiderenergysystem

Integrationandefficiency

●Highefficiency:thenetworkscanoptimisethedistributionanduseofheatandcooling,reducingenergywaste.

●Economiesofscaleinrenewableintegration:district-widesystemscanenablemoreefficientandcost-effectiveadoptionofrenewablesduetotheaggregateddemandandinvestment.

Energysecurity

●Energysecurity:citieswiththermalnetworks,withaconsiderableshareofrenewables,hadonaveragemorestablepricesduringthe2022gascrisis

Weaknesses

Infrastructureandcost

●Highinitialcosts:itcanbechallengingandexpensivetoupgradeandconstructthermalnetworksindenselybuiltareas

Systemintegrationanddistribution

●Interoperabilityissues:needforcompatibilityamongdifferentsystemsandstandards

●Unevengeographicaldispersion:thedistributionofdistrictheatingandcoolingnetworksisvariableacrosstheEU,withastrongpresenceinsomeMemberStatesandalmostnoneinothers

Opportunities

Sustainabilityandresourceopportunities

●Localresourceutilisationforvaluecreation:smartthermalnetworkscapitaliseonlocalandexistingresources,suchaswasteheatandrenewables,addingvalueandpromotingsustainability

●Lowertemperatures:thedecreasingenergydemandinbuildingsallowsforlowertemperaturenetworksandtheintegrationoflow-temperaturerenewablesandwasteheat

Marketopportunities

●Urbanisation:increasingurbanpopulationscreateademandforefficientandsustainableurbanenergysolutions

●Newbusinessmodels:opportunitytovaloriseflexibilityandthermalstoragecapacities

Threats

Marketdevelopmentchallenges

●Economicuncertainty:economicdownturnscanreduceinvestmentinnewtechnologies.

●Energymarketfluctuations:volatileenergypricescanimpactthecost-effectiveness.

●Competitionfromothersolutions:competitionwithestablishedsystemslikenaturalgasnetworksorindividualheatpumpscouldlimitadoption

Stakeholderandlabourchallenges

●Stakeholdercommitment:establishingathermalnetworkrequiresconsensusamongdiversestakeholdersandlong-termdedicationfromlocalauthorities

●Lackofskilledworkers:shortageofconstructionworkersingeneralandweldersinparticular

Cybersecuritychallenges

●Cybersecurityrisks:increaseddigitalisationraisestheriskofcyber-attacksonenergyinfrastructure

Source:JRCcompilation

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1.Introduction

Theroleofdistrictheatingandcooling(DHC)networksisslowlytransforming.Fromsimplyensuringasufficientheatsupplytobecominganactiveanddynamicpartofthewiderenergysystem.Traditionally,DHCnetworksheavilyreliedondispatchablegenerationcapacity,meaningfossil-fuelledgenerationandcogeneration.Intheearlystagesofdistrictheating(DH)development,fossilfuelswerecombusted,generatingheatofupto200“oC,whichwasthendistributedthroughoutcitiesviasteampipelines.ThemodernDHCnetworks,referredtoassmartthermalnetworksinthisreport,operatewithpressurisedwateratlowertemperatures,ahighershareofrenewableenergies(RES),andmanagemorecomplexsystemswithamultitudeofsupplyanddemandpoints.Theyutiliseadvancedcontrolstrategiesandmonitoringsolutions(e.g.,sensorsandsmartmeters)tooptimisetheflowofheatorcoldandintegrateahighershareofRESefficiently.

TheimportanceofsmartthermalnetworksisgrowingastheshareofRESissteadilyincreasing,reinforcedbyclimatemitigationambitions,improvedcompetitivenessofcleanenergytechnologies(e.g.solarandwindpower),aswellasimminentenergysecurityconcerns.ThisreportprovidesanoverviewofthecurrentstatusandtrendsofdistrictheatingandcoolingnetworksandsmartthermalnetworksintheEuropeanUnion(EU).

Smartthermalnetworkisasystemintegrationtechnologythatcanhelpcitiesmovetowardscarbonneutralityinacost-effectivewaybyofferingtheabilitytoutiliselocallowcarbonresourcesaswellasproviderelativelyinexpensivestoragesolutions.DHCnetworkscanbeanintegratedpartofthewiderenergysystemsbyprovidingflexibility,throughinterfacetechnologies,likecombinedheatandpower(CHP)andpower-to-heat.Simplyput,DHCnetworkscanproduceandstoreheatwhenthereisanabundanceofelectricityandincreaseCHP’selectricityproductionwhenthereisashortageofelectricitygeneration(i.e.whenitseconomicalfortheDHCorCHPoperatorstodoso)6.Thepotentialofthissectoralintegrationislargerwhenthesystembecomessmarter,moreefficientandoperatesonalowertemperature.

Figure1:4thgenerationdistrictheatingandcoolingsystemcomparedtopredecessors.

Source:(Lund,etal.,2014).

(6)Advancedcontrolandmanagementofgeneratorsinmulti-sourcesystemscanservethesamepurposeasthermalenergystorage,excepttheenergyisstoredintheunburntfuel.

9

AsillustratedinFigure1,theoperatingtemperaturesofDHCnetworkshavedecreasedovertime,drivenbythegoalofreducingthermaldistributionlossesandincreasetheefficiencyofthethermalgeneration.Akeyenablerforreducingtheoperatingtemperatureshasbeenthedecreasedtemperaturedemandsofbuildings,forexampleduetobetterinsulatedbuildings,andtheadoptionofdigitaltoolsforoptimisingthesystemoperation.Mostnetworks,definedassmartthermalnetworks,operateonalowtemperatureforthemajorityoftheyear(i.e.notover80°C)7,makingtheintegrationofmoreREStechnologies,likegeothermalheat,wasteheat,andheatpumps,morecost-effective.IncreasingefficienciesandloweringthetemperatureofthenetworksenablesfasterintegrationofRESandwasteheat.GrowinginvestmentinRESalsoincreasesthedemandforsmartthermalnetworks.Consequently,investmentsinRESandsmartthermalnetworksaremutuallyreinforcing.

Furthermore,wasteheatfromindustrialprocessescanbeapositiveenergysourceforlow-temperatureDHnetworks,withasupplyof50-60oCwithareturnwatertemperatureof25oC(Lund,etal.,2014).DependingontheleveloftemperatureofthewasteheatsourceandtheleveloftemperatureoftheDHCnetwork,whetherthesourcewillneedanincreaseintemperatureornot.Forexample,iftheDHnetworkworksat90°Candthewasteheatisat50°Cthissourceisnotdirectlyuseful8.Aswasteheatisaplace-fixedsourceofenergy,thewaytofixthesesituationsistoincreasethetemperaturewith,forinstance,heatpumps.Forindustryzoneswithmultiplewasteheatsources,awaterloopcanbeusedtorecoverthewasteheatfromvariousprocessesanddeliverittoacentralheatpump,whichbothcooldownthewaterloopviatheevaporatoranddeliversthewasteheatatusefultemperaturetotheDHsystemviathecondenseroftheheatpump.Thewasteheatcollectionwaterloopwouldavoidtheneedforadedicatedheatpumpforeachwasteheatsource.

Theconceptofasmartthermalnetworkisidenticaltotheoneofa4thgenerationdistrictheating(4GDH)system.Duringthelastdecade,theconcepthasbeenusedtodescribeadvancedDHsystems,characterisedbylowertemperaturesandintelligentcontroltechnologies.Theoverarchinggoalofthe4GDHistoattainafullydecarbonisedenergysystem.

Box1:ThetransformationofDHCintosmartthermalnetworksischaracterisedbyseveralkeyfeatures.

Aggregateddemands:Aggregationofthermaldemandsarebecomingvaluablecommoditiesbecausetheyenable:

-Loadshiftingforbothshortandextendedperiods.

-Effectivebalancingservicesfortheenergysystem.

-Cost-effectivedevelopmentandutilisationoflow-gradethermalsources,suchaswasteheat.

Digitalisationandoptimisation:Theuseofdigitalisation,incombinationwithoptimisation,allowsforahigherutilisationofresourceswhilereducingthecostsassociatedwithfutureRES-basedenergysystems.

Low-temperatureheatsources:Low-temperatureheatsources,includingrenewablesandwasteheat,arecentraltoensuringhighenergyefficiencyofheatpumps.

Electrifiedthermalsupply:Inanelectrifiedthermalsupplysystem,district/centralthermalenergystorage,combinedwithlarge-scaleheatpumpsandelectricboilers,functionsasalargeelectricitybatterycapableofutilisingexcesspowergeneration,particularlyfromRES,andavoidpowerconsumptionforheatingpurposesduringperiodsoflowshareofRES.Multi-sourceandmulti-fuelDHCsystems:Thesesystemsofferthepossibilityofeffectiveshiftingbetweeninpute