LED professional Review (LpR) – Jan/Feb 2026 – LpR#113

Light+Building2026

Wearepleasedtopresentthefirstissueofthisyearwithaspecialfocus editionpublishedjustaheadofLight+Building,theleadinginternational tradefairforlightingandbuildingservicestechnology.

Againstthebackdropofrapiddevelopmentsinthelightingsector,this issuebringstogetherarichselectionoftimelyandforward-looking contributions.Twoin-depthinterviewsprovidevaluableperspectives: KlausVamberszky,formerCTOoftheZumtobelGroup,shareshisviews onthefutureofprofessionallighting,whileMarkusHellespeakswithIALD presidentCarlaWilkinsaboutcurrentandemergingtrendsinlighting design.J.NormanBardsleyexaminestheroleofLEDlightinginthe contextofclimatechange,supportinghisanalysiswithrecentresearch findings.

Akeythematicfocusofthisissueissmartlighting,includinginsightsfrom theLS2025IEEEWorldConference,newapproachestoin-field commissioningandreconfiguration,anddevelopmentsinsensor technologybasedonthermalintelligence.Furtherarticlesexplorethe impactoflightonthehumanorganism,highlightedbyanHCLstudy relatedtoParkinson’sdisease,aswellascurrenttopicsinphotometric dataforlightandLEDs.

TheissueopenswithanoverviewbyElenaScaroni,SecretaryGeneralof LightingEurope,followedbyourcompactInternationalLightingNews section.

WewishyouanengagingreadandasuccessfulLight+Building.

YoursSincerely, SiegfriedLuger

Founder&CEOofLugerResearche.U. PublisherofLEDprofessional,TrendsinLighting,LpSDigital,andtheGlobalLightingDirectory

8 Chances&ChallengesfortheLighting Sector–LightingEuropeatLight+ Building2026inFrankfurt byElenaScaroni

20 KlausVamberszky,FormerCTOat ZUMTOBELGroup compiledbyEditors,LEDprofessional

LIGHTINGDESIGNINTERVIEW

28 CarlaWilkins,IALDPresident compiledbyEditors,LEDprofessional

GLOBALWARMING

32 TheRoleofLEDLightinginClimate Change

byDr.J.NormanBardsley,ChiefAnalystatthe InternationalSolid-StateLightingAlliance

SMARTLIGHTING–EVENT

38 ReportontheIEEESustainableSmart LightingWorldConference,LS2025 byStuartMucklejohn,Secretary–LS2025 InternationalScientificCommittee

40 SupplementalAmbientLighting InterventiontoImproveSleepin Parkinson’sDisease:APilotTrial

46 LumaNet–ANovelMethodforInfield LuminaireCommissioningand Reconfiguration byJohannesRüdisser,JanStark,Prof.Stefan Zudrell-Koch

MEASUREMENT

52 LightingMetricsDemystified: HowPhotometricDataDrivesQuality andEfficiency byXavierDenis,Nichia

SMARTLIGHTING–SENSING

54 FromLightingControltoThermal Intelligence bySaaraGuastella,Casambi;KevinJohnstone, Danlers;BartdeJong,Calumino

ElenaScaroni

ElenaScaroniisLightingEurope’s SecretaryGeneral,appointedin June2023.

Priortothisrole,sheservedas policydirectorsincejoining LightingEuropeinSeptember 2016.Scaronihasbeenatthe forefrontofadvocatingthe interestsoftheEuropeanlighting industryintherecentecodesign andenergylabellingregulationsfor lightsources.

PriortojoiningLightingEurope, shespenteightyearsinEuropean affairsatEnel,amultinational energycompany.Her responsibilitiesincludedmanaging relationswiththeEuropean Parliamentonallrelevantissues suchasclimate,energyand corporatesocialresponsibility.

ShestudiedinRomeandParis andholdsamaster’sdegreein law,specializinginEuropean Affairs.

Frankfurt

Thisyear,LightingEuropewillbeparticipatinginLight+Building2026inFrankfurt, withitsownboothinHall4.1(FOY3).We willalsobehostingthreeeventsinthe EuropaSaal(Hall4),aimingtopromotedialoguewithintheEuropeanlightingindustry.

Itseemsthatwehavearrivedatapivotal moment.Ontheonehand,manylighting companiesaresufferingfromacombinationofstagnatingEuropeaneconomy, aggressivecommercialstrategiesfromcertainthirdcountriesandtheresultingflood ofnon-compliantproductsbeingsoldin Europeviaonlinemarketplaces.Onthe otherhand,eventsthatwouldneverhave happenedbeforearehappeningnow.

TheEUGreenDealisbeingimplemented, andatthesametime,therearemassiveeffortsmadebytheEUinstitutions, tosimplifyrules.TheSCIPdatabase, createdwiththegoalofreportingon allhazardoussubstancespresentinall productshasbeendeemedineffective,and theEuropeanCommissionisproposingits deletion.OtheramendmentstotheEU GreenDeallegislationproposedbythe EuropeanCommissionarecallingforthe digitalizationofalmostallprintedinformationrequiredtoaccompanyaproduct. ThedeletionofSCIPandthedigitization ofproductdocumentationcouldbring substantialsavingstoourcompanies,in linewithLightingEurope’sadvocacy.We willworktoensurethatbothtakeplace.

FurtherLightingEuropeEvents:

9March,17.00–18.00:

’LightingEuropeOpenDays’–Focusonourprioritypolicyareas ValueofLightandBetter Enforcement.

11March,10.30–11.30:

Risingunfaircompetitionfromthirdcountriesseemstobeopeningthedoorto apossible’MadeinEurope’labelto supportEuropeansustainableandquality products.Wearecurrentlydiscussing LightingEurope’spositionindetail,andwe willensurethatitisdulyconsideredinthe politicaldebate.

Themassiveshifttowardsdecarbonizing ourindustryandimprovingtransparency regardingtheenvironmentalfootprintof lightingproductsisalsoremarkable.CompaniesareinvestinginEPDsandLCAs, aswellasineffortstoincreaseefficiency andreduceemissions.Ourassociation isencouragingthemtodosobycreating andharmonizingproduct-specificrulesfor

lightingproducts,andbysupportingdecarbonizationeffortsviatrainingsessions andadedicatedcohortprogramforall LightingEuropemembers(andmembers ofournationalassociations).Somekey issues(e.g.thoserelatedtolifetime)remain unresolved.Weareworkingonthemto improvethetoolsavailabletoourindustry fordecarbonization.Alllightingcompanies arewarmlyinvitedtohelpus.

Asisoftenthecase,unexpectedopportunitiesmayariseduringtimesofcrisis.We willhavethechancetodiscusstheseand moreattheLightingEuropeeventsduring Light+Building,aswellasinmoredetailat ourinternalLightingEuropemeetings.

CEOsEvent:ChallengesandOpportunitiesfortheLightingIndustry 10March,15:15–19:00, EuropaSaalHall4,Level0 TheCEOdebatewillbethechanceto finallymeetalltogetherandheartheirviews fromtheleadingmanagersoftheEuropean lightingindustryandfromaninfluential policymakerattheEuropeanCommission.

TheeventstartswithakeynotebyRobert Nuij(EuropeanCommission–DGEnergy) onEUenergyefficiencystrategies,includinglightingproducts,followedbyaCEO debatemoderatedbyme,ElenaScaroni (LightingEurope).

CEOsoflightingcompanies, AlfredFelder ofZumtobel, Mark-OliverSchreiter ofERCO, HubertusVolmertofTrilux, PaoloCerviniofGewiss,and AsTempelmanofSignify,willexchangeviews andanswerquestionsfromtheaudience onchallengesandopportunitiesforthe LightingIndustry.

Somekeytopicsarelikelytoemergefrom theLightingEuropeCEOevent:Smart buildings&IoTintegration,sustainability demands,andfaircompetition.

’LightingEuropeOpenDays’–Focusonourprioritypolicyareas SustainabilityandProductRules. Chances&ChallengesfortheLightingSector–LightingEuropeatLight+Building2026in

Theeventconcludeswithanetworking cocktail.Wearelookingforwardtomeeting youthere.Registerforalleventsonour website. ■ E.S.

www.lightingeurope.org

SignifyReportsFull-year

2025SalesofEUR5.8Billion

www.signify.com

Signify(Euronext:LIGHT),theworldleaderin lighting,announcedthecompany’sfourth quarter&fullyearresults2025.

Signify’sperformancein2025highlightedthe resilienceofourbusinessaswerespondedto reduceddemand,therippleeffectoftariffs, andpricepressureinourtradechannels.In thiscontext,ourfull-yearresultsweremixed. OurprofessionalbusinessgrewintheUSbut declinedinEurope.Ourconsumerbusiness deliveredsustainedgrowthinallregions exceptChina.Connectedlightingshowed stronggrowthinbothprofessionaland consumermarkets,butthiswasoffsetbya declineinnon-connected,particularlyintrade channels.Bothbusinessesmaintaineda stronggrossmargin.OEMfacedreduced demandandpricingpressure.AdjustedEBITA was8.9%,andwegeneratedstrongcash flowofEUR440million,or7.6%ofsales.

“Inthefourthquarter,continuedconnected growthandastrongtoplineperformancein theUSandIndiawasoffsetbydeclinesina numberofotherregions.TheadjustedEBITA marginforthequarterwasimpactedbya lowercontributionfromConsumer,OEMand Conventional.”saidAsTempelman,CEOof Signify.

Throughwhatwillbeatransitionalyearfor Signify,ourimmediatepriorityistooutperform inatoughmarketbystrengtheningour commercialandoperationalexcellence,and costcompetitiveness.Todrivethis,weare announcingaEUR180millionprogramto structurallyresetourcostbase,whichwill unfortunatelyimpact900rolesacrossSignify. Tofocusthebusinessforfuturesuccess,we areconductingafullstrategyandportfolio reviewandwillshareourconclusionsatour CapitalMarketsDayonJune23,2026.

Weanticipatethechallengingconditionsto persistthrough2026.Consideringthe divergingdynamicsinourendmarkets,we arenotprovidingguidanceonfull-yearsales atthisstage.WeexpectanadjustedEBITA marginof7.5-8.5%,andfreecashflow generationof6.5-7.5%ofsales.Weintendto payanincreaseddividendofEUR1.57per share,whilepausingsharebuybacksfor

capitalreductionpurposes,topreserve financialflexibilityduringourstrategicreview.

“Iwanttothankouremployeesfortheir commitmentandresiliencethroughoutthe year.Theirdedicationisessentialaswe positionSignifyforsustainable,profitable growth.”

HavingcompleteditsBrighterLives,Better World2025sustainabilityprogram,Signifywill introduceitsnewsustainabilityprograminthe firstquarterof2026.Inthefinalquarterofthe 2025program,Signifyachievedthefollowing results:

Signifysurpassedits2025targettoreduce greenhousegas(GHG)emissionsacrossits entirevaluechainby40%againstthe2019 baseline-doublethepacerequiredbythe ParisAgreement.

Circularrevenuesreached37%ofsales, beyondthe2025targetof32%.Themain contributionwasfromserviceableluminaires intheprofessionalbusiness,withstrong performanceintheAmericas.

Brighterlivesrevenueswereat34%ofsales, surpassingthe2025targetof32%.This includedstrongcontributionfromconsumer andspeciallightingproducts.

Thepercentageofwomeninleadership positionsremainedat27%,whichdidnot meetthe2025targetof34%.Signifyremains committedtoincreasingrepresentation throughfocusedhiringpracticesfordiversity acrossalllevels,andthroughretentionand engagementactionsthatreduceattrition.

Thecompanywillstructurallyresetitscost baseandestablishcontinuousproductivity improvements,whileremainingcommittedto itsoperatingmodel.

Todrivethis,SignifyisannouncingaEUR180 millioncostreductionprogram.Themajority ofsavingswillbedeliveredthrough2026,with thefullbenefitrealizedin2027. ■

CasambiAnnounces LeadershipTransition: IntroducingaDualCEOModel

www.casambi.com

Casambi,theleaderinsmartlighting,has announcedasignificantleadershipchangeas thecompanyadoptsadualCEOmodelto driveitsnextphaseofgrowthandinnovation. Effectiveimmediately,KristianJenkinsand TimoPakkalawillassumetherolesof Co-ChiefExecutiveOfficers.Kristianwillfocus onSales&Operations,whileTimo,oneof Casambi’sfounders,willleadTechnology.

Thisnewleadershipstructurereflects Casambi’scommitmenttoagilityandstrategic depth.BycombiningKristian’sproven operationalexpertisewithTimo’svisionary technologicalleadership,Casambiis positioningitselftoaccelerateglobal expansionanddelivercutting-edgesolutions toitscustomers.

KristianjoinedCasambiinearly2019andhas sincecontributedtothecompany’s internationalgrowththroughaseriesofkey roles.From2020to2023,hefocusedon developingsalesandexpandingregional partnershipsinBeneluxandtheMiddleEast, strengtheningCasambi’spresenceinthese markets.

In2023,whilstcompletinghisExecutiveMBA, KristianrelocatedtoSingaporetosupportthe openingofCasambi’sAPACofficeas BusinessDevelopmentLeadandamemberof theregionalmanagementteam.SinceApril 2024,hehasledCasambi’sIndianexpansion asCountryManager,deliveringexcellent resultsandbuildingstrongfoundationsfor futuregrowth.

KristianishighlyvaluedwithinCasambiand amongpartnersforhisglobalexperience, collaborativeapproach,andcommitmentto drivingsuccess.

KristianJenkins,Co-CEO:“I’mhonoredto takeonthisrolealongsideTimo.Ourdual leadershipapproachensureswecanstay closetoourcustomerswhilecontinuingto innovateatthecoreofourtechnology. Together,weaimtostrengthenCasambi’s positionasthegloballeaderinsmartlighting control.”

TimoPakkala,Co-CEO:“Casambiwas foundedontheideaofchallengingthestatus quo.Thisnewmodelreflectsthatspirit. KristianandIshareaclearvisionforthe future,andwe’reexcitedtoleadCasambiinto itsnextchapterofgrowthandtechnological excellence.”

ThecompanyalsoannouncedthatMark McClear,whohasservedasCEOsince2023, willstepdownbymutualagreement.During histenure,Markplayedapivotalrolein Casambi’ssuccess,drivingsignificantgrowth andstrengtheningglobalcustomer relationships.

KayPawlik,ChairoftheBoard:“Onbehalfof theentireboard,Iwanttoexpressour heartfeltgratitudetoMark.Hisdedication, tirelessefforts,andleadershiphavebeen instrumentalinCasambi’sjourneyoverthe pasttwoyears.Wewishhimhappinessand successinthisnewchapteroflife.”

Casambi’sdualCEOmodelunderscoresits beliefthatcollaborationandcomplementary strengthsarekeytonavigatingthe complexitiesofthesmartlightingindustry. WithKristianandTimoatthehelm,the companyiswell-positionedtocontinue deliveringinnovativesolutionsandexceptional valuetopartnersworldwide. ■

InstrumentSystemsAppoints

Dr.MarcLünnemannasNew CEO

www.instrumentsystems.com

TheDALIAllianceandtheInternational AssociationofLightingDesigners(IALD)have announcedacollaborationaimedat strengtheningtheconnectionbetweenlighting designprofessionalsandcutting-edgedigital lightingcontrolstandards.

Thispartnershipaimstoempowerspecifiers, designers,andarchitectsbysharing knowledge,launchingeducationalinitiatives, andfosteringmoresubstantialalignment acrossthelightingecosystem.Itfocuseson jointeffortsineducation,outreach,andthe promotionofopenstandardstoenhance lightingoutcomesinarchitectural, commercial,andpublicspaceprojects.

“Lightingdesignersplayacriticalrolein shapingthebuiltenvironment,”saidPaul Drosihn,GeneralManageroftheDALI Alliance.“PartneringwiththeIALDallowsus tobuildadirectbridgetothedesign community,ensuringthatDALI-based technologiescontinuetosupportcreativity, flexibility,andperformancewhereitmatters most.”

Thecollaborationreflectsbothorganizations’ commitmenttosupportingamoreconnected, informed,anddesign-forwardindustry.

“Thispartnershipisaboutensuringdesigners haveaccesstothetools,training,and

standardstheyneedtodeliverexceptional results,”saidChristoperKnowlton,CEOofthe IALD.“ByworkingwiththeDALIAlliance, we’rehelpingtoclosethegapbetween evolvingcontroltechnologiesandreal-world designpractice.”

TheDALIAllianceandtheIALDviewthis collaborationasacrucialstepinempowering lightingprofessionalstomakeinformed decisionsaboutcontrolsystemsandin supportingthelong-termsuccessof sustainable,human-centriclightingdesign.

MoreabouttheDALIAllianceanditswork standardizingandadvancingintelligentlighting canbefoundatdali-alliance.org.Information ontheIALDanditsadvocacyforthelighting designprofessionandtheglobalcommunity canbefoundatiald.org ■

AACTechnologiesandEulitha AnnounceUseofEulitha’s OpticalLithographyfor

VolumeARWaveguide Production

www.aactechnologies.com

AACTechnologies,agloballeaderin advancedconsumerelectronicscomponents andmodules,andEulithaAG,apioneerin high-throughputopticallithography, announcedattheSPIEAR/VRConference thatAACwillbeginutilizingEulitha’s lithographytechnologyforthevolume productionofAugmentedReality(AR) waveguides.Thisrepresentsasignificant milestoneintheindustry’spursuitofscalable andaffordableARwaveguidemanufacturing.

ARdevicesarewidelyexpectedtobecomea primaryinterfaceforubiquitousaccessto informationthroughsmalldisplaysplacedin theuser’sfieldofview.Thesedevicesare especiallyeffectivefortheseamlessdeliveryof AI-generatedinformation.Periodic nanostructures,oftencalleddiffractiveoptics, arepatternedonglassplates(waveguides)to enableimagestobeprojectedtotheuser’s eyewhilemaintainingaclearviewofthe surroundings.Eulitha’sproprietaryoptical lithographytechnologyenablesthe high-fidelityprintingofhigh-resolutionperiodic patternsrequiredforthesediffractiveopticsat

alowcost.Thetechnologyisakintothe photolithographymethodsthatserveasthe backboneforsemiconductorfabrication, leveragingthesameestablishedsupplychains forphotomasks,photoresists,andEDAtools.

ProductionusingEulitha’stechnologyis expectedtobeavailableatAAC’s manufacturingfacilitieswithinthisyear, markinganimportantsteptowardmeetingthe growingdemandfornext-generationAR devices.

HowardTao,HeadoftheAR/VRBusiness UnitatAACTechnologies,said:“Wehave beencollaboratingwithEulithatoqualifytheir uniqueopticallithographytechnologyforour productionlinesandhavebeenimpressedby theperformance.Weareenthusiasticabout thepotentialofthisadoptiontoboostour positioninthiscompetitivefield,thankstothe high-qualityandlow-costproductionenabled byEulitha’stools.”

HarunSolak,CEOofEulithaAG,added:“The adoptionofourtechnologybyaleading manufacturerlikeAACisasignificantstepin therecognitionoftheadvantagesweofferto ourcustomers.Webelievethehigh throughputandreliabilityenabledbyoptical lithographywilladdressthescalabilityissues currentlyfacingtheARindustry.Welook forwardtocontinuingourcollaborationwith AACTechnologiestoenabletheproductionof leadingARdevicesforconsumersworldwide.”

AACTechnologiesbringsdeepexpertisein opticalcomponents,modules,and system-levelintegration.Throughin-house capabilitiesandpartnerintegration,AAC offersfullyfunctionalcompositeARdisplay modules,includingwaveguides,lightengines (LEA),electrochromics,push/pulllenses,and eye-tracking,toitsglobalcustomers.

Thiscollaborationhighlightsashared commitmentbyAACandEulithatoaccelerate theindustrializationofARwaveguidesand supportthebroaderecosystemasARmoves towardmass-marketadoption. ■

Inaboldmovetoenhancelightingsolutions, InventronicsandSynapseWirelessstrengthen theirlong-termpartnershiptooffercustomers afullyintegratedapproachoflighting componentsandcontrolsystems.

SynapseWireless,aleadingproviderof innovativewirelesslightingcontrol,offers intuitiveandreliablesolutionsthataddress coreneedsacrosstheboard:empowering designers,optimizingassetvalueforowners, reducingoperationalenergyuse,and boostingmanagementefficiency.Thisdelivers onthesharedgoalofsustainedenergy savingsandprecisecostcontrol.Withhigh marketacceptance,particularlyinNorth America,Synapsehasbuiltarobustservice andsupportecosystemfortheglobaloutdoor andsportslightingmarkets.

Inventronics,apremierglobalproducerof lightingsystemsolutions,adherestoitscore principleofbeing“customer-centricand creatingvalueforclients.”Itslightingsystem solutionscovermultipleapplicationfields, includingstreetandarea,sports,horticulture, industrial,commercial,retail/residential, hospitality,architectural,andsignage. Currently,Inventronics’productsolutionsare soldinover100countriesandregions.The companyhasestablishedacomprehensive businessnetworkinmorethan30ofthese locations,creatingacompetitiveadvantage through“globalcoordinationandlocal response.”Asaresult,Inventronicsholds significantinfluenceinthelightingindustry.

Inventronicsisrecognizedforitsexpertisein LEDdrivers,whileSynapseisknownforits advancedlightingcontrolsolutionsand SimplySnapcloudsoftware.Thiscollaboration offerscustomersaprofessionaland harmonizedsystemtailoredforsportsand outdoorapplications.Theircombined experienceresultsinproven,stablesystem setups.

Asnewfeaturescontinuetoemergeinboth driverandcontroltechnologies,customers increasinglyseekcomponentsthatarefully compatible.Toaddressthisneed,a dedicatedcompatibilitylistcoveringvalidated driver–controlcombinationswillbereleased. Thisaimstoreducetestingtimeand streamlinethedesign-inprocessforlighting professionals. ■

amsOSRAMSellsNon-optical Analog/mixed-signalSensor BusinesstoInfineon

ams-osram.com

amsOSRAMsellsnon-optical analog/mixed-signalsensorbusinessto InfineonforEUR570mincash,reduces pro-formaleverageratioto2.5andiscreating theleaderinDigitalPhotonics.

“Withthefocusedsaleofournon-optical automotive,industrial&medicalsensor businesstoInfineonforEUR570millionin cash,weareeffectivelykillingtwobirdswith onestone:weareacceleratingthe deleveragingofourbalancesheetwhileatthe sametimecreatingacompellingstrategic pureplay–theleaderinDigitalPhotonics.We areemergingasthePhotonicsPowerhouse, offeringthebroadestsuiteofcutting-edge semiconductoremitting&sensingplatforms, uniquelypositionedtocapturethemajor inflectionpointsinDigitalPhotonicsacross automotive,AugmentedRealitysmart glasses,biosensing,homeandindustrial robotics,AIdata-centeropticalinterconnects andpotentiallyevenvisionaryapplicationslike laserfusion.”saidAldoKamper,CEOofams OSRAM. ■

FarnellandFulhamAnnounce GlobalDistribution Partnership

Farnellhasannouncedanewglobal distributionpartnershipwithFulham, expandingaccesstoadvancedLEDdrivers, emergencylightingandintelligentcontrol solutionsforcustomersacrossEMEA.The agreementstrengthensFarnell’slighting portfoliointheregion,supportingengineers andbuyersacrosscommercial,industrialand architecturallightingapplications.

Fulhambringsmorethan30yearsofexpertise inLEDdrivers,modules,emergencylighting andintelligentcontrolsystems. HeadquarteredintheUnitedStates,the companyoperatesglobally,with manufacturinginIndia,supplychannelsin IndiaandChina,andastrongpresence

acrossEurope.Itsportfolioincludesindoor andoutdoorLEDdrivers,emergencylighting systems,UVballasts,andsmartcontrol technologies,alldesignedtomeetkey internationalstandards,includingCE,ENEC, DALI-2,andUL.

Throughthispartnership,Farnellwilldistribute Fulham’slightingsolutionsglobally,improving availabilityandaccesstofuture-ready technologiesforengineersandbuyers worldwide.

TheagreementincludesFulham’scorelighting portfolio,includingemergencylighting systems,indoorLEDdrivers,and constant-voltagedriverplatforms,withkey rangesincludingtheHotSpot®Series, WorkHorse®DALI-2constant-currentdrivers, andtheThoroLED®Seriesforarchitectural lighting,signage,andLEDstripapplications.

Customerbenefitsinclude:

• Broaderaccesstocertified,future-ready lightingtechnologies.

• GlobalavailabilitythroughFarnell’s establisheddistributionnetwork.

• Supportforawiderangeoflighting applicationsandformfactors.

• AccesstoFulham’sdeeptechnical expertiseandprovenproductplatforms.

JoseLok,GlobalProductCategoryDirector–OnboardComponents&SBC,Farnell,said: “Farnellhasastrongcommitmenttoadding valueforourcustomers,andthispartnership expandsbothchoiceandaccesstoinnovative lightingtechnologies.Byworkingwith Fulham,weareenablingcustomers worldwidetosourceadvancedLEDdrivers, emergencylightingandcontrolsolutions throughatrustedglobaldistributionpartner.”

AntonyCorrie,CEO,Fulham,added:“Fulham isextremelyexcitedtoembarkonthisnew relationshipwithFarnellGlobal.Asa Yorkshireman,andwithFarnellheadquartered inLeeds,I’mespeciallyproudtoworkwitha companyI’veknownandrespectedsince startingmycareerinthemid-1990s.This partnershipbringstogethersharedvalues, strongheritageandacommitmenttoglobal innovation.FarnellwillbesellingFulham’sLED drivers,emergencybatterybackupsolutions, exitsignsandUV-Cpowersystemsacross theirglobalcustomerbase.” ■

FromSunlighttoNightLight withILIORA

www.tridonic.com

Lightingstreetsandsquaresensuressafety andthusincreaseswell-being.Inconnection withclimatetargets,energyself-sufficiency anddigitalization,themarketfor solar-poweredoutdoorluminairesisgrowing.

Theyrelievethestrainonthepowergridor enablelightingwheretherearenopowerlines. Topavethewayforaneweraof solar-poweredoutdoorlightingTridonicis launchingILIORAtechnology.

Traditionalstreetlightingwasdevelopedfor powergridsthatchangedmoreslowlyinthe pastthantheydotoday.Thecostsof expandingthelightinginfrastructurearehigh, especiallywhenconstructionworkinpublic spacesisnecessarytolayundergroundcable installations.Inmanypartsoftheworld,the powergridsarestillunderdeveloped,and electricitypriceshaveexplodedinmany countriesinrecentyears.Even well-developedpowergridsareincreasinglyat riskofblackoutscausedbypowersurges.

Newoutdoorlightingtorelievetheburdenon powergrids:Newtechnologicaladvances offerhighpotentialstosignificantlyimprove theoutdoorlightingnetworkandhelpsave

energyandreduceCO emissions. Technologiessuchasadvancedsmartcity solutionsandthehigherqualityand performanceofsolartechnology,batteries andLEDsofferopportunitiestoreducethe burdenoncurrentpowergrids.TheEU climatetargets,whicharelaiddownintheEU GreenDeal,amongotherplaces,havedrawn attentiontoself-sufficient,sustainable solutions.However,toachievethis,outdoor lightingneedstoberethought.

ILIORA–fromsunlighttonightlight: Solar-poweredluminairesmakeoutdoor lightingmoreflexibleandsustainable.The ILIORAsolutionfromTridonicheraldsanew erainoutdoorlighting.Attheheartofthe technologyisanew,D4i-certifiedDC/DCLED driverthatenablestheeasyintegrationof differentsensorsandlightmanagement systems.Thismeansthatforeveryapplication theperfectsolutioncanberealized.Solar lightingthusbecomesareliableandscalable solutionformodernurbanenvironments.An MPPTcontrollermanagestheenergyflowand ensuresthatthestoredenergyisefficiently transferredtotheLEDluminaires.Integrated sensorsandstate-of-the-artcontrols complementthesolution,bothforasmall groupofluminairesandforasmartcity application.

Asnoexcavationorcablingworkisrequired,

installationcostscanbesignificantlyreduced. Thesustainabledesign,whichdoesnot requireamainsconnection,ensuresthatthe operationoftheluminairesdoesnotproduce anyemissions.Astheyareindependentofthe mainspowersupply,thesystemscontinueto functionwithoutinterruptionevenintheevent ofapowerfailure.Inaddition,modernmasts canbeusedassensorhubsthatcollect environmentalandusagedata.Inthisway, thelightingsupportthesmartcityconcept.

ILIORAPlanner:Toolfordimensioning components:Tooptimizethesystem architectureofsolar-poweredoutdoor luminaireseasilyandefficiently,Tridonicoffers atoolcalledtheILIORAPlanner.Byanalyzing project-specificrequirementsandusing location-baseddata,thecalculationtool automaticallyselectstheappropriate components,suchassolarmodules,batteries andLEDmodules,anddimensionsthemto meetthedesiredrequirements,forexample withregardstothedailylightingduration.The interactiveuserinterfacewithgraphical instructionsenablespreciseconfigurations basedonstreettype,lumenrequirementsand desiredautonomyduration.

ILIORAinuse:Incombinationwithasensor forambientlightandmotiondetection, footpathsandcyclepathsinurbanparkscan beilluminatedmoreefficiently.Ifthesensor

detectsmovementfrompedestriansor cyclists,thelightintensityisincreasedandthe luminaireshinesbrighter.Whenthereareno peopleinthevicinityoftheluminaire(s),the lightingisdimmedtoaverylowlightintensity orevenswitchedoffcompletelytosave energy.

ILIORAcanalsobeusedattemporary constructionsites,forexampleonmotorways. IndividualluminaireswiththechronoSTEP function,inconjunctionwithalightsensor, ensurethatthelightingisswitchedon automaticallyassoonasdarknessfalls.

Anotherapplicationisinindustrialareaswith connectedcarparks.There,theluminaires canbeconnectedtoeachotherviaa basicDIMWirelessmeshnetworkand controlledvialightsensorsandmotion detectors.ThankstobasicDIMWireless, groupsofluminairescanbeswitchedonand offsimultaneouslybyremotecontrol.

Inruralareaswithouttheirownpowersupply, suchasmountainhutsinalpineregionsor safarilodgesinAfrica,sensorswithambient lightandmotiondetectionautomatically switchonthelightingwhendarknessfallsor increasethelightintensityassoonas movementisdetected. ■

EmergencyLightingBuiltfor InstallationReadiness

www.ledvance.com

Emergencylightingisafundamental componentofbuildingsafety,helpingto ensurethatoccupantscansafelyexitaspace intheeventofapowerfailureoremergency. Forcommercial,industrialandpublic environments,thecorrectspecificationand installationofemergencyluminairesis essentialnotonlyforsafety,butalsofor compliancewithcurrentregulationsand standards.

Whenplanninganemergencylightingsystem, specifiersandinstallersmustconsiderarange ofpracticalfactors.Theseincludelightoutput andcoverage,emergencyduration, environmentalprotection,andlong-term reliability.Installationefficiencyisalsoan importantconsideration,particularlyon projectswithtightdeadlinesorlimitedaccess. Increasingly,flexibilityandfutureproofingare alsovalued,allowingsystemstobeadapted asbuildinguseorrequirementschange.

Tosupporttheseneeds,LEDVANCEhas expandeditsemergencylightingportfoliowith twonewsolutionsdesignedtocombine dependableperformancewithpractical installationfeatures.

TheLEDVANCEEmergencyTwinSpot luminaireisdesignedforapplicationswhere

highvisibilityanddirectionalemergency lightingarerequired.Suitableforuseinboth indoorandoutdoorenvironments,its IP65-ratedhousingoffersprotectionagainst dustandmoisture,makingitappropriatefor areassuchaswarehouses,carparks,plant roomsandexternalescaperoutes.Two adjustablespotlightsallowinstallerstodirect lightpreciselywhereitisneeded,helpingto improvecoveragealongdefinedescape paths.Theluminaireisequippedwitha LiFePO4battery,providingaminimumofthree hoursemergencyoperation,andissupplied withmountingaccessoriestohelpstreamline installationonsite.

ComplementingthisistheWallpackCombo IP65luminaire,whichintroducesLEDVANCE’s Plug&Upgradeconcepttooutdoor emergencylighting.Thismodularapproach allowsthewallpacktobeinstalledinitiallyasa standardluminaire,withemergency functionalityaddedlaterviaanemergencykit ifrequired.Thiscanbeparticularlyusefulon projectswhereemergencylighting requirementsmaychange,orwherebudget andprogramconsiderationscallforaphased approach.Optionscomewithorwithoutan integratedphotocell-providingadditional flexibilityforexteriorapplications.

“Safetyandeaseofinstallationarethetwo pillarsofeveryprofessionallightingproject,” saidNeloNeves,ManagingDirector, LEDVANCE“Thesenewemergency luminairesunderscoreLEDVANCE’s commitmenttosolutionsthatarenotjust technicallyexcellent,butalsogenuinelyeasier tofitandcommission.”

SupportedbyLEDVANCE’stechnical documentationandinstallerguidance,the newluminairesareintendedtohelp professionalsdelivereffectiveemergency lightingsolutionswhilekeepinginstallationand futuremaintenanceconsiderationsfirmlyin mind. ■

OrionEnergySystems,Inc.(NASDAQ:OESX) (OrionLighting),aproviderofenergy-efficient LEDlighting,electricvehicle(EV)charging stationsandmaintenanceservicessolutions, hasannouncedthatithasinitiateda$3million LEDlightingandelectricalinfrastructure engagementforoneoftheleading food-servicedistributorsintheUnitedStates.

Theinitiativeconsistsofdeploymentsand upgradesofLEDlightingandelectrical infrastructureatmultiplefacilitiesofoneof Orion’slongtimeenterprisecustomers.The food-servicedistributoroperatesmorethan 150facilitiesintheUnitedStates.

“Ourlongtimeongoingrelationshiptypifies howOrionservessomanyofAmerica’s largestandmostimportantextended enterprises,”saidOrionChiefExecutive OfficerSallyWashlow.“Wearegreatly appreciativethatsomeofthemostprominent industrialnamesintheU.S.relyonOrionon suchaconsistentbasis.”

“Thelargenumberoffacilitiesoperatedbythis industryleaderhavearecurringneedfor installingandupgradingtheirLEDlightingand electricalinfrastructureatmultiplelocationsat anyonetime,”saidOrionChiefOperating OfficerScottGreen.“Orionhasenjoyedavery closepartnershipwiththiscustomerfora numberofyears,anditisgratifyingtoseeit continuetogrow.”

Orioniscommittedtooperatingresponsibly throughoutallareasofourorganization. ■

TwoSeniorLeadersElevated toAssociateExecutive DirectorRolesas OrganizationsLeverage StrategicPartnership www.ies.org

TheIlluminatingEngineeringSociety(IES)and AudioEngineeringSociety(AES)announced thepromotionoftwoseniorstaffmembersto newlycreatedAssociateExecutiveDirector positions,effectiveJanuary1,2026.The appointmentsreflectbothorganizations’ commitmenttostrategicgrowthand enhancedindustryengagementfollowingtheir recentsharedmanagementarrangement.

BrienneWillcockhasbeenpromotedto AssociateExecutiveDirector,Strategy, Standards,andIndustryEngagementatIES. WillcockcurrentlyservesasDirectorof EducationandStandardsatIES,whereshe hasbeeninstrumentalinadvancingthe society’stechnicalexcellenceandeducational programs.

GrahamKirkhasbeenpromotedtoAssociate ExecutiveDirector,Strategy,Events,and IndustryEngagementatAES.Kirkcurrently servesasDirectorofMarketingandBusiness DevelopmentatIESandwillbringhis extensiveexperienceinstrategicpositioning andeventexpertisefrombothAESandIESto hisnewrole.

“BrienneandGrahamhavebeeninvaluablein helpingIESachievesignificantmilestonesover thepastseveralyears,”saidColleenHarper, CEOandExecutiveDirectorofIESand ExecutiveDirectorofAES.“Thesepromotions recognizetheirleadershipandexpertisewhile positioningbothorganizationsforcontinued innovationandgrowth.Asweintegrateour managementstructures,havingleadersof theircaliberfocusingonstrategyandindustry engagementwillbeessentialtoservingour respectivetechnicalcommunities.”

“I’mhonoredtostepintothisexpandedrole andcontinueadvancingIES’sworkatthe intersectionofeducation,standards,and industrycollaboration,”saidBrienneWillcock. “AsIESevolves,aligningourstrategic initiativeswiththeneedsofthelighting communityismoreimportantthanever.Ilook forwardtohelpingguidethatdirectionand ensuringourworkremainsbothrigorousand deeplyrelevant.”

“I’mexcitedtoreturntoAESandhelpstabilize andgrowanorganizationwithsucharich legacy,”saidGrahamKirk.“AEShaslong beenknownforitsexceptionaleducational eventsandpublications,andIlookforwardto buildingonthatfoundationtoservetheaudio engineeringcommunityandstrengthenthe Society’spositionastheleadingvoicein professionalaudio.”

Bothappointmentssupportthestrategic visionofIESandAEStomaintaintheirdistinct identitieswhileleveragingoperational synergiesthroughsharedmanagement.The newroleswillfocusonadvancingeach organization’sstrategicpriorities, strengtheningindustrypartnerships,and enhancingmembervalue.

AbouttheIES:Establishedin1906,the IlluminatingEngineeringSocietyisthe recognizedtechnicalandeducational authorityonillumination.Ourmissionisto improvethelightedenvironmentbybringing togetherthosewithlightingknowledgeandby translatingthatknowledgeintoactionsthat benefitthepublic.Weprovideavarietyof professionaldevelopment,publications, networkingandeducationalopportunitiesto ourmembershipofengineers,architects, designers,educators,students,contractors, distributors,utilitypersonnel,manufacturers andscientistsinnearly60countries.Through ourAmericanNationalStandardsInstitute (ANSI)accreditedprocess,wepublishand maintaintheLightingLibrary®,withover100 standardswrittenbysubjectmatterexpertsin ourtechnicalcommittees.Inallourefforts,we strivetoimprovelifethroughqualityoflight.

BridgeluxExpandsinto

High-PowerOutdoorLighting withNewHigh-EfficacyLED Platforms

www.bridgelux.com/smd-outdoor

Bridgelux,aleadingdeveloperand manufacturerofLEDlightsourcesolutions, recentlyannounceditsstrategicexpansion intothehigh-poweroutdoorlightingsegment withthelaunchofthreeadvancedproduct families:Ceramic3535,EMC5050,and CSP2424.Thesenewplatformsdeliver class-leadingefficacy,exceptionalcolor consistency,andoutstandinglifetime performance,settinganewbenchmarkfor professionaloutdoorluminaires.

Designedspecificallyfordemandingstreet, area,high-bay,andfloodlightingapplications, thenewBridgeluxhigh-poweroutdoor portfolioachieves200–230lm/Wat ∼2Watts operatingcondition(CRI70and4000K), representingoneofthehighestefficacies commerciallyavailableinthehigh-power categoryasshowninthefollowingtable.This breakthroughenablesluminairemanufacturers todramaticallyreducesystempower consumption,lowertotalcostofownership, andmeetthemoststringentenergy-efficiency regulationsworldwide.

“Bridgeluxhaslongbeenrecognizedfor deliveringinnovative,high-performanceLED

solutions,”saidDr.Yi-QunLi,ChiefExecutive OfficerofBridgelux.“Withthislaunch,weare bringingthatsameinnovationandqualityto thehigh-poweroutdoormarket.Thesenew productscombinerecord-breakingefficacy withthereliabilityandcolorqualitythat designersdemandforcriticalinfrastructure lightingprojects.”

TheCeramic3535,EMC5050,andCSP2424 familiesarefullyqualifiedandinvolume production.Samplesandevaluationboards areavailableimmediately,withstandardlead timesforproductionquantities.

AboutBridgelux:Bridgeluxisaleading providerofhigh-performanceLEDlight sourcesthathelpcustomersachievesuperior opticalperformance,costefficiency,and sustainabilitygoals.Withdecadesof innovationinphosphor,packaging,andchip technology,Bridgeluxcontinuestopushthe boundariesofsolid-statelighting. ■

NichiaInnovationGallery StagedDuringLight+ BuildingWeekasPartof WiderMilestoneYear

www.nichia.co.jp/en

AsNichiamarksthekeymilestonesof70 yearsinbusinessand30yearssince pioneeringthewhiteLED,itsEuropean divisionhasorganizedatwo-day,invite-only InnovationGallery.Heldon10and11March atBernhardKnausFineArt,aprestigiousart galleryinFrankfurt,theshowcasetakesplace duringLight+Buildingweek(8–13March 2026).Theregionalteamchosethistimingto complementthetradefairexperiencefor visitorsalreadyinthecity.

Nichia’sportfoliogoesbeyondgeneraland architecturallightingthatdominatesthe exhibitionhallsatLight+Building.Atthe InnovationGallery,visitorswillbeableto engagewiththefullbreadthofNichia’s optoelectronicsrange,fromautomotive, industrialandmedicaltohorticulturaland otherspecialistapplications.Thegalleryalso offersanopportunitytoexplorewhere technologiesalreadyintersecttodayand wherefuturecrossoverscouldunlocknew creativepossibilitiesforlightingprofessionals.

Ratherthanattemptingtoreplicatealarge tradeshowstand,theInnovationGallery enablescustomersandpartnersto experiencenoveldemonstrationstailoredto realuse-cases,highlightingintegration opportunitiesinacalmandcreative environment.Thesettingisdesignedto encouragelonger,moremeaningful conversationswithengineersandcompany representatives,aswellasinformalexchange amongvisitors.

TheInnovationGalleryisjustaseven-minute walkfromtheLight+Buildingexhibition grounds.Foraddedconvenience,ashuttle servicewillbeavailableforregistered participants.

“Anniversariesgiveusamomenttoreflect— andtolookahead,”saidAnnaMüller,Headof MarketingatNichiaEuropeGmbH.“Our InnovationGalleryinFrankfurtoffersa contemporarysettingtomarktwomilestones: Nichia’s70-yearanniversaryand30years sincethecompanydevelopedthewhiteLED. Bysteppingoutsidethetraditionaltrade-fair setting,wearecreatingspacefordeeper dialogueacrossourfulloptoelectronics portfoliobeyondgenerallighting—from automotiveandUVtoindustrialandlaser technologies.” ■

ZumtobelRealizesJames Turrell’sSkyspace

“Sustenance2024”atthe UniversityChildren’sHospital Zurich www.zumtobel.com

WiththeSkyspace“Sustenance2024,” AmericanlightartistJamesTurrellhascreated anextraordinarylightspaceattheUniversity Children’sHospitalZurich,Switzerland,that combinesart,space,andlightintoaunique experience.TurrellreferstoSkyspaceas observationroomsinwhichnaturallightflows throughopeningsintheceilingand,in combinationwithLEDlighting,creates fascinatingeffectswithinthespace.

TheSkyspace“Sustenance2024”isintended forpatientsandtheirfamiliesaswellasfor staff.Afteradisturbingconversation,a delicateprocedureoradifficultdiagnosis,a visittotheSkyspaceprovidesawelcome distraction.Thecontemplativeperceptionof lightandskyinvitesvisitorstopauseand meditate.Theellipsoid,eight-meter-high SkyspaceintheheartoftheUniversity Children’sHospitalZurichstretcheslikea domevaultovertwofloors.Thewallstaper upwardstoformanellipticallightinlet.The spaceisilluminatedbyapreciselycoordinated LEDlightingsystem.433high-performance

lightsdistributedacrossthreelightrings choreographuniquecolorgradients.The LEDsalsoilluminatetheuppermostdiffuserin theroofstructure,whichinturnservesasa reflectivemediumandpusheshuman perceptiontoitslimitsbycontrastingthedark floorandtheroofopening.

TheSkyspace“Sustenance2024”thusfits seamlesslyintotheconceptoftheZurich Children’sHospital,whichfocusesonhealing architecture:roomspositivelysupporthealing throughart,naturalmaterials,and human-centeredlighting.Asgeneralplanner andlightingpartner,Zumtobelwas responsibleforthetechnicalimplementation oftheprojectandcontributeditsexpertise frommanyyearsofcollaboratingwithJames Turrell.“Thisworkofartisthemostelaborate andbestwehaveevercreated,”says ZumtobelprojectmanagerJürgenHäcker.As projectmanageronsite,hecoordinatedallthe trades.

Inadditiontofireprotectionandearthquake safety,theSkyspace“Sustenance2024”had toovercomeaveryspecialchallenge:the children’shospital’shelipadisintheimmediate vicinity.Athree-tondomeonrailsslidesover theartspacewheneverarescuehelicopter approaches–aswellasinrain,snow,or strongwinds.Whentheroofisclosed,it createsaneffectofdimensionlessness.The shellthatclosesthedomeisilluminatedby anotherringoflightinsuchawaythatthe lightingeffectremainsextraordinaryeven whenthedomeisclosed.

TheSkyspaceconsistsofindividual,precise 3Delementsthatformthisuniquespace.The floorandbenches,madeofgraniteslabs weighingupto120kilograms,werecutwith millimeterprecisiontocreateahighlyaccurate jointpattern.Thewholestructureisheldin placebyaninvisiblesteelframeworkthathas beenmountedinsuchawaythatitisboth absolutelystableandmovable.

Withapassionforlightandadeep understandingofJamesTurrell’shighly sophisticatedlightart,ZumtobelLichtAGhas putitsheartandsoulintothisuniquetask. Themagnificent,solution-orientedexternal teamcoordinatedbyZumtobelLichtAGalso deservesspecialmention.

ARadiantPartnership:Thelong-standing partnershipbetweenZumtobel,ledbyHerbert Resch,theZumtobelfamily,andJamesTurrell hasalreadyproducedseveraluniquepieces.

In2018,Zumtobelwasthelightingpartnerfor Turrell’sexhibition“TheSubstanceofLight”at theFriederBurdaMuseuminBaden-Baden, Germany.Andin2015,hedesignedthe ZumtobelGroup’sannualreportunderthetitle “ExtraordinaryIdeas–Realized.”Withthe newlightroomattheChildren’sHospitalin Zurich,thiscreativecollaboration,which combinesartandsocialresponsibility,has reachedanewhighpoint.

“Wehavebeenworkingcloselyandtrustingly withJamesTurrellformanyyears.Hisartistic standardsinspireustimeandagaintobreak newgroundinourapproachtolight.Weare particularlyproudtohavebeenabletorealize thisuniqueprojectattheUniversityChildren’s HospitalinZurich—becausehere,artand lightingcontributetohealingandgivehope,” saysIsabelZumtobel,DirectorofArts& CultureattheZumtobelGroup. ■

DALIAllianceLaunchesTest andCertification SpecificationsforWirelessto DALIGateways

www.dali-alliance.org

TheDALIAlliance,recognizedasthe internationalauthorityinlightingtechnology standardization,proudlyannouncesthe launchofitsnewtestandcertification specificationsforWirelesstoDALIGateways. Thisgroundbreakingreleaseallowsseamless controlofwiredDALIdevicesfromeither Bluetooth®NLC(NetworkedLightingControl) orZigbeewirelessecosystems,andprovides accesstodatafromDALIsystems,pavingthe wayforincreasedinteroperabilityandflexibility inthelightingindustry.

Thenewspecificationsallowwiredand wirelessconnectivitywithinlightingsystems andgivetheflexibilitytochoosethebest lightingcontrolsolutionfortheapplication. Thetestandcertificationspecificationswill ensurethatstandardizedgatewaystranslate effectivelybetweenDALIsystemsandthe wirelessprotocols,BluetoothNLCorZigbee, providingacruciallinkbetweenthesediverse technologies.Thesestandardizedgateways promotemarketconfidenceandaccelerate theadoptionofDALI-basedsolutionsinthe evolvingworldofsmartbuildingtechnologies.

KeyFeaturesandBenefits

• ThenewspecificationsallowwiredDALI products,bothDALI-2andD4i,tobe controlledwithinwirelessecosystems, offeringgreaterflexibilityandadaptability.

• Gatewaystranslateseamlesslybetween DALIandBluetoothNLCorZigbeewireless protocols,providingrobustinteroperability.

• Thesestandardizedgatewaysallow

wirelessecosystemstoaccessdatafrom wiredDALIdevices,includingtherichsetof luminaire,powerandenergyand diagnosticsdataavailablefromD4i luminaires.

AsPaulDrosihn,GeneralManageroftheDALI Alliance,explains,“Theintroductionofthese testandcertificationspecificationsfor WirelesstoDALIGatewaysisasignificant milestone.Itopensupnewpossibilitiesfor integratingDALIwithwirelesssystems, creatingabroaderrangeofsolutionsforthe industry.Bystandardizingthesegateways, we’repromotinginteroperabilityandproviding apathforwardfordevelopers,manufacturers, andprofessionalsinbuildingautomation.”

“ThecompletionoftheBluetooth®NLCto DALIGatewaySpecificationsuitemarksa significantmilestoneforlightingcontrol systems,”saidNevilleMeijers,CEOofthe BluetoothSIG.“Thesestandardizedgateways enableseamlessintegrationbetweenDALI’s trustedwiredsystemsandtheleading wirelesslightingstandard.Thecollaboration highlightsthepowerofopen,industry-defined standardsindrivinginnovation,building marketconfidence,anduntappingthefull potentialofintelligentlightingsystemsto deliverconsistent,value-addedsolutionsfor buildingmanagementandoccupants.”

Together,thesestandardizedgateways extendthereachofDALIintobothBluetooth NLCandZigbeeecosystems,ensuring interoperabilityacrosstheindustry’sleading wirelessplatforms.

“TheintegrationofZigbeeandDALI representsapivotalmomentintheevolution ofsmartlightingandbuildingautomation,” saidTobinRichardson,PresidentandCEOof theConnectivityStandardsAlliance.“Zigbee’s robust,interoperablewirelessmesh technology,combinedwiththeprecisionand scalabilityofDALI’sdigitallightingcontrol, bridgesthegapbetweenfield-levellighting

devicesandwirelessIoTnetworks.The standardizedgatewaysenhanceflexibility, lowerdeploymentcomplexity,andpavethe wayformoreintelligent,energy-efficient buildings.”

TheDALIAlliance’scommitmenttoopen, industry-definedspecificationsisessentialto ensurethecorrectfunctionalityofthese gateways.Unlikeclosed,proprietary solutions,standardizedgatewayshelpavoid compatibilityissuesandensureaconsistent userexperienceacrossdifferentsystems. ■

KAISTDevelopsOLED TechnologywithDoublethe ScreenBrightness

www.kaist.ac.kr

Organiclight-emittingdiodes(OLEDs)are widelyusedinsmartphonesandTVsthanks totheirexcellentcolorreproductionandthin, flexibleplanarstructure.However,internal lightlosshaslimitedfurtherimprovementsin brightness.KAISTresearchershavenow developedatechnologythatmorethan doublesOLEDlight-emissionefficiencywhile maintainingtheflatstructurethatisakey advantageofOLEDdisplays.

KAIST(PresidentKwangHyungLee) announcedonthe11thofJanuarythata researchteamledbyProfessorSeunghyup YoooftheSchoolofElectricalEngineeringhas developedanewnear-planarlightoutcoupling structure*andanOLEDdesignmethodthat cansignificantlyreducelightlossinsideOLED devices.*Near-planarlightoutcoupling structure:athinstructurethatkeepsthe OLEDsurfacealmostflatwhileextracting moreofthelightgeneratedinsidetothe outside. OLEDsarecomposedofmultiplelayersof

ultrathinorganicfilmsstackedontopofone another.Aslightpassesthroughtheselayers, itisrepeatedlyreflectedorabsorbed,often causingmorethan80%ofthelightgenerated insidetheOLEDtobelostasheatbeforeit canescape.

Toaddressthisissue,lightoutcoupling structuressuchashemisphericallensesor microlensarrays(MLAs)havebeenusedto extractlightfromOLEDs.However, hemisphericallensesprotrudesignificantly, makingitdifficulttomaintainaflatformfactor, whileMLAsmustcovermuchlargerareathan individualpixelsizestoachievesufficientlight extraction.Thiscreateslimitationsinachieving highefficiencywithoutinterferencebetween neighboringpixels.

ToincreaseOLEDbrightnesswhilepreserving aplanarstructure,theresearchteam proposedanewOLEDdesignstrategythat maximizeslightextractionwithinthesizeof eachindividualpixel.

Unlikeconventionaldesignsthatassume OLEDsextendinfinitely,thisapproachtakes intoaccountthefinitepixelsizesactuallyused inrealdisplays.Asaresult,morelightcanbe emittedexternallyevenfrompixelsofthe samesize.

Inaddition,theteamdevelopedanew near-planarlightoutcouplingstructurethat helpslightemergeefficientlyintheforward directionwithoutbeingspreadtoowidely.This structureisverythin—comparablein thicknesstoexistingmicrolensarrays—yet achieveslightextractionefficiencycloseto thatofhemisphericallensesofthesamelateral dimension.Asaresult,ithardlyundermines theflatformfactorsofOLEDsandcanbe readilyappliedtoflexibleOLEDdisplays.

BycombiningthenewOLEDdesignwiththe near-planarlightoutcouplingstructure,the researcherssuccessfullyachievedmorethan atwofoldimprovementinlight-emission efficiencyeveninsmallpixels.

Thistechnologyenablesbrighterdisplays usingthesamepowerwhilemaintaining OLED’sflatstructureandisexpectedto extendbatterylifeandreduceheatgeneration inmobiledevicessuchassmartphonesand tablets.Improvementsindisplaylifespanare alsoanticipated.

MinJaeKim,thefirstauthorofthestudy, noted,“Asmallideathatcameupduring classwasdevelopedintorealresearchresults throughtheKAISTUndergraduateResearch Program(URP).”

ProfessorSeunghyupYoostated,“Although manylightoutcouplingstructureshavebeen proposed,mostweredesignedforlarge-area lightingapplications,andmanyweredifficult toapplyeffectivelytodisplayscomposedof numeroussmallpixels,”adding,“The near-planarlightoutcouplingstructure proposedinthisworkwasdesignedwith constraintsonthesizeofthelightsource withineachpixel,reducingopticalinterference betweenadjacentpixelswhilemaximizing efficiency.”Hefurtheremphasizedthatthe approachcanbeappliednotonlytoOLEDs butalsotonext-generationdisplay technologiesbasedonmaterialssuchas perovskitesandquantumdots.

Thisresearch,withMinJaeKim(Department ofMaterialsScienceandEngineering,KAIST; currentlyaPh.D.studentinMaterialsScience andEngineeringatStanfordUniversity)and JunhoKim(SchoolofElectricalEngineering, KAIST;currentlyapostdoctoralresearcherat theUniversityofCologne,Germany)as co–firstauthors,waspublishedonlineon December29,2025,inNature Communications. Papertitle:“Near-planar lightoutcouplingstructureswithfinitelateral dimensionsforultra-efficientandoptical crosstalk-freeOLEDdisplays”DOI: 10.1038/s41467-025-66538-6

ThisresearchwassupportedbytheKAIST UndergraduateResearchProgram(URP),the Mid-CareerResearcherProgramandthe FutureDisplayStrategicResearchLab ProgramoftheNationalResearchFoundation (NRF)ofKorea,theHumanResource DevelopmentProgramoftheKoreaInstitute forAdvancementofTechnology(KIAT),and theKoreaPlanning&EvaluationInstituteof IndustrialTechnology(KEIT). ■

High-Efficiency

Phosphor-FreeYellowLED TechnologyRedefines

Low-Color-Temperature

Lighting 573600737@qq.com

Abreakthroughinsilicon-basedGaNLED technologyisenablinganewgenerationof energy-efficient,phosphor-freelighting solutionsforeducation,infrastructure,and outdoorapplications.

Thegloballightingindustryhaslongfaceda fundamentaltrade-offinyellowandultra-low

colortemperatureLEDs:eitheracceptlow efficiencyandthermalinstabilityorrelyon phosphor-conversionwithitsinherent drawbacksincolorpurity,aging,andreliability. Anewtechnologicalmilestonenow overcomestheselimitations.

ANewBenchmarkforYellowLED Performance:In2018,Nanchang Silicon-BasedSemiconductorTechnology Co.,Ltd.achievedamajorbreakthroughwith thedevelopmentofasilicon-basedgallium nitride(GaN)yellowLEDchip,settinganew worldrecordinluminousefficacyforyellow LEDs.Thechipdelivers318lm/Wat565nm, withawall-plugefficiencyof51.6%,while maintaininghighcolorpurityandexceptional thermalstability.

Unlikeconventionalphosphor-converted solutions,thechipemitsyellowlightdirectly, eliminatingphosphor-relateddegradationand colorshiftatthesource.Comparedwith traditionalAlGaInPyellowLEDs,itshows significantlyreducedtemperature-induced lightoutputdroop,makingithighlysuitablefor demandingreal-worldenvironments.

EnablingaNewGenerationofPhosphor-Free LightingSystems:Buildingonthiscore technology,twomajorphosphor-freelighting productcategorieshaveemerged:

Multi-ColorLEDPhosphor-FreeLightingfor Human-CentricEnvironments:Designedfor applicationsrequiringhighvisualcomfortand spectralcontrol—suchasclassroomsand educationalfacilities—multi-colorLED phosphor-freesystemsenabledynamic spectrumadjustmenttailoredtodifferentuse scenarios.

Byreducingshort-wavelengthbluelight throughprecisespectraltuning,these systemshelplowereyestrainandmitigate myopiarisksamongadolescents.Typical classroomluminairesdeliver3000lmat36W, withRa>90,R9>90,andacorrelatedcolor temperatureadjustablefrom2000Kto5000K.

GoldenLightLED:ANewStandardfor OutdoorandRoadLighting:Forroad,tunnel, andoutdoorlighting,thehigh-efficiencyyellow GaNLEDchipiscombinedwith high-performanceredLEDstocreateaunique golden-lightspectrum,entirelyfreeof phosphorconversion.

TheresultingLEDpackagesdeliverwarmlight

at1800–2200K,withRa>70,excellent luminousefficiency,andoutstanding environmentaladaptability.Instreet-lighting systems,efficaciesofupto145lm/Wat2000 Kareachieved—alevelpreviously unattainableatsuchlowcolor temperatures. ■

InternationalConferenceon EnergyEfficiencyandSmart CommunitiesReturnsto

FrankfurtinMarch2026

Paolo.Bertoldi@ec.europa.eu

TheInternationalConferenceonImproving EnergyEfficiencyinCommercialBuildingsand SmartCommunities(IEECB&SC’26)willtake placeonMarch11,2026,inFrankfurt, Germany,followedbytheEuropeanESCO Conference2026onMarch12,2026.Both eventswillbeheldatMesseFrankfurtin conjunctionwiththeLight+Building exhibition.

Nowinits13thedition,IEECB&SChas establisheditselfasaleadinginternational platformfortheexchangeofknowledgeand bestpracticesonenergyefficiency, sustainability,andsmartsolutionsfor non-residentialbuildings,districts,andcities. Theconferencebringstogetherresearchers, policymakers,ESCOs,utilities,engineers, architects,technologyproviders,financiers, andcommercialpropertystakeholdersfrom aroundtheworld. ■

Amendment:Thecommentaryinissue#112 includedafigureregardingLEDenergy conversionthatwasn’taccurate.Theeditors reviewedandconsequentlyadjustedthe figuretoamoreexactrangeof40-60%.

Dipl.-Ing.KlausVamberszky: “LightspectrafromUVtoIRstillholdthe biggestuntappedpotential.”

Withmorethanfourdecadesofexperiencespanningproduct development,R&Dleadership,andinternationalstandardization, FormerCTOatZUMTOBELGroup,Dipl.-Ing.KlausVamberszkyhas witnessed—andhelpedshape—themosttransformativephasesofthe lightingindustry.FromtheearlydaysofCAD-supportedlightingdesign totheLEDtransitionandtoday’sdebatesonsustainability,regulation, andhuman-centriclighting,hisperspectivebridgestechnology, architecture,andstrategy.Inthisinterview,hereflectsonpastturning points,currentstructuralchallenges,andthedirectionsthatmaydefine thefutureoflightinginEuropeandbeyond.

zumtobelgroup.com

LEDprofessional: Mr.Vamberszky, howwouldyoudescribeyourprofessionaljourneyinthelightingindustry, andwhichstagesorroleswereparticularlyformativeforyou?

KlausVamberszky: Ienteredthelightingindustryin1985,afterhavingstudied mechanicalandchemicalengineering attheViennaTechnicalUniversity(“Verfahrensingenieurwesen”anderTUWien) asamechanicalengineeranddesigner. ItwasthetimeofCAD/CAM,ofthefirst softwareprogramstosupportlighting design.AtthattimeZumtobelevenparticipatedasanexhibitorattheCEBIT fairinHannover,alongwiththeirCADsupplierMatraDatavision.

TwoofmyrolesthatIwouldliketohighlightare:

• HeadofproductdevelopmentatZumtobel;workingpersonallywithfamous architectslikeEttoreSottsass,JeanMichelWilmotte,NicholasGrimshaw butalsotheyoungAustriandesigner, KarinPesau.Creatingbenchmark standardproductsandrealizingchallengingcustomizedprojectsolutions, andbeingclosetocustomersand markets.ItwasthetimewhenZumtobelenteredthearchitecturallightingsegment,withthefirstspotsand downlightstobedeveloped(downlight familyOPTOS(Figure 1),spotlight ARTOS).Prestigiousprojectsneeded tobedelivered,mainlyintheUK(for exampleWaterlooStation(Figure 2) orCAASouthampton).

• CTOinthetimesoftheLEDtransition. HereIwasalsoactinginparallelas headofR&DatTridonic.Enteringnew

businesseslikeLEDretrofitbulbs,exploringbothpolymeraswellassmall moleculeOLEDsinjoint-venturesand cooperationswithFraunhoferand CambridgeDisplayTechnologies–workingonnewtechnologiesbutalwayswithaneyeontheprofessional lightingmarketandapplication.This addedastrategiclevertoallthedecisionsthatneededtobetakenand alsoinvolvedthetopicofIntellectual Property.Inadditiontothis,itwas thetimeofandaftertheacquisition ofThornwithalotofso-calledpostmerger-integrationinitiatives.Ialso enjoyedtheglobalviewofit,theinvolvementinZumtobelUSaswellas theearlyandfrequenttraveltoJapan andKorearegardingLEDandOLED suppliers.

LEDprofessional: Lookingatthe lightingdomaintoday,howwouldyou characterizeitscurrentstatecomparedtoearlierphasesofdevelopment?

KlausVamberszky: Thecurrentstate is–inmyview–characterizedbytoo muchfocusonenergysavingandcost: itisasignofahighlycommoditized business.Eveninproductdesignand architecturethereistoomuch“mainstream”;everythinglooksthesame.This wasdefinitelydifferentintheyearsbefore2000.

LEDprofessional: Whatchangesover thepastdecadehavehadthegreatestimpactontheindustry—technological,economic,orregulatory?

KlausVamberszky: Byfarthebiggest changewascreatedbytechnology;the transitionfromfluorescentandhighpressuredischargelampstoLEDs.Theformerdominantlampindustrylostimportanceandleadership;theluminaire industryisveryfragmentedandnowthe lightingindustryisleftwithout“industrial leadership”.Ononesidethisisadisadvantage(nocommonvoiceanymore), andontheotherside,itleavesroomfor theownpositioningofcompanies.The LEDwasthefirstlightsourcethatwas notdevelopedforgeneralillumination, andthisbroughtsomeveryinteresting developments.

Irememberverywell,thetalkIgaveat LpS2011inBregenzwhereIpredicted theproductioncostofa2,000lmdownlightbasedonHaitzandMoore’slawto comedownfrom120€in2010toapprox.20€in2020(Figure 3).

Atthetime,thepredictionwasviewed withskepticism;todayweknowitmay evenhavebeentooconservative.IalwaysliketocitethelawofAmarainthis respect:“Wetendtooverestimatethe short-termimpactofnewtechnologies butunderestimatetheirlong-termeffects”.Technologymanagementisand hasalwaysbeenoneofmyfavoriteinterests.

Theotherbigimpactwasthefinancial crisesin2007/2008whichreducedthe newconstructionvolumedramatically; eventodayithasn’trecoveredtoitsold peak.

LEDprofessional: WheredoyoucurrentlyseethemainstrengthsofEuropeanlightingcompanies,andwhere dostructuralchallengesremain?

KlausVamberszky: Thestrengthofthe Europeanlightingcompaniesistheholisticunderstandingofthe“lightingapplication”,includingculturalaspects.Itisa balancedviewconsistingofarchitecture andaesthetics,understandinglighting, technology,optics,andtheapplication itself.Thechallengeisonthecostand complexitysideofthebusiness;the trade-offbetweenmassproductswith economiesofscale,andalotofproduct nicheswithsmallquantities.

LEDprofessional: LEDtechnology hasbecomefirmlyestablished.In yourview,wherearethemostrelevantimpulsesforfuturedevelopment onthelightsourcenowcomingfrom?

KlausVamberszky: Istillseethebiggest potentialinthelightspectra,ranging fromUVuptoIRradiation;thereisa lotofinterestingscientificworkbeing doneonthisrightnow.Inthefuturewe mighthaveanefficientmulti-channel multi-colorlightsourcewithoutwavelengthconversionmethods,avoiding theStokeslosses.Intermsoftechnology,StevenPaoliniandhisTelelumen companyhavealreadyshownwhatis possiblethere,andintermsofarchitectureIwouldliketomentiontheearly workofthearchitectPhilippeRahm, fromFrench-speakingSwitzerland,on “climaticarchitecture”.

Anotherinterestingtopicisthebrightnessoflightsources,includinglaser diodesontheupperendoftherange, andorganiclightemittingdiodes(OLEDs) onthelowerend.Theselightsources havebeenaroundforquiteawhile,and usedinotherindustries,like,forexample,automotivelighting.Butsofarthey havenotbeenwidelyusedingeneralillumination.

Thelightingindustryisaveryslowbusiness:Itisdifficulttogetaquickreturn oninvestment.However,theremaybe sometailwindfromsustainabilityandcirculareconomyfornewlightsourceslike theonesmentionedbefore.

LEDprofessional: Howdoyouassessthegrowingimportanceofconnected,software-drivenlightingsys-

temscomparedtotraditionalproduct innovation?

KlausVamberszky: Well,thisisacomplextopic:Lightingisamediatorbusiness,thereal“end-user”oflighting (meaningthepeoplesittingbelowthe luminairesinstalled)isnotintegratedin thechoiceofthelightingsystemitself. Thereareverydifferent“verticals”inprofessionalbuildings,likeHVAC(heating, ventilationandcooling),firedetection, entrancecontrol,andothers,andthe finaluserisuntrainedinthesystems inplace.Thebusinesscaseisdifficult, asenergysavingsachievedthrough

controlsand“lightingcomfort”arenot understoodbymany.Thishasactually beenshownbytherecentdiscussions about“indoorenvironmentalquality”on aEuropeanlevelinconnectionwiththe EPBDdirective(EnergyPerformanceof Buildingsdirective).

LEDprofessional: Whatrolewillinteroperability(e.g.DALI,Zhaga),open interfaces,anddataplayinthefuture developmentoflightingsolutions?

KlausVamberszky: Thisquestion,too, hasdifferentviewingangles;thereisthe customerandthespecifierwhowant

Figure3: PredictedversusactualcostdevelopmentofLEDdownlights(2010–2020)presentedbyMr.VamberszkyattheLpS2011inBregenz. Source:ZumtobelGroupKlausVamberszky.

tochoosethebestproductstofitthe application,andtheyneedtobeinteroperable.Theproducerhimselfmight prefertodifferentiatehimselfviaanown proprietarysystem.ThesituationinmobileoperatingsystemslikeIOSandANDROIDshowsthisdilemmaquitewell; interoperabilityismoreeasilyachieved inaclosedproprietarysystemthaninan openone.

Regardingdata,wehavetodifferentiate between“neutralsystemdata”andthe personalsettings,intheunderstanding of“mylight”accordingto“myage”and “mypreferences”.Thisiswheredata protectionplaysabigrole.

LEDprofessional: Aretheretechnologicaltrendsthatcurrentlyreceive toomuchattention—andothersthat youbelievearestillunderestimated?

KlausVamberszky: Asalreadymentioned,thereistoomuchfocusonenergyefficiencyandCO2,andtoolittle focusonglare,individualinfluenceslike age,sex,culturalbackgroundandmood oftheuser.Longtermeffectsoflight arestillnotconsideredatasufficient

level,andusabilityoflightingsystemsin generalisbad.Itisanexpertbusiness dominatedbytechniciansandregulation inafragmentedindustry.

LEDprofessional: Aremarketdynamicstodaydrivenmorebytechnologicalprogress,orbychangingexpectationsfromdesigners,planners,operators,andendusers?

KlausVamberszky: Inthepastthe dynamicscamefromtechnological progress,mainlyonthelightsource itself.Actually,somehow,thereisa vacuum,duetothedifficulteconomic situation,complexityofthebusiness, uncertainactivitiesintheregulatoryenvironment,andsaturationofLEDefficiencygains.Thefuturewillbringanend totheenergyefficiencyrace;resource efficiencywillreplaceenergyefficiency (Figure 4).

LEDprofessional: Inwhichapplicationareasdoyouseethegreatest potentialforhigh-qualityandvaluedrivenlightingsolutionsinthecoming years?

KlausVamberszky: Ibelieveinhealthcare–thereisalotofongoingresearch ontheinfluenceoflightonthehuman body,andmaybestillinthe“workplace lightingarea”likeofficeandeducation. Peoplearestressedintheseenvironments,burnoutratesareincreasing,and “mentalwellness”getsmoreandmore attention.Allthiscanbepositivelyinfluencedbyagoodlightinginstallation.

Thisisalsotrueforprivatelife;lookat theactivitiesofsmallstart-upsandcompanieslikeLYSorZeitgeber.Personal lightsensorsattachedtopeople,dedicatedLightingApp’sandlightdietsare definitelysomethingtowatch.

LEDprofessional: Howimportant isitformanufacturerstodevelopa deeperunderstandingofusagescenarios,operation,andthefulllifecycle oflightingsystems?

KlausVamberszky: Itisofgrowingimportance;deliverandforgetaremethodsfromthepast.Servicecontentis increasingrapidly,butinalotofmarkets wehavea2stagemulti-channelsales process,andthestoryisdifficulttotell,

andevenmoredifficulttosell.Intheend itcanonlybedoneinadirectbusiness, eitherinprojectsorwithkeyaccounts.

LEDprofessional: YouhavebeenactivelyinvolvedinEuropeanlighting committees.Whatroledostandards andnormsplaytodayinshapingthe industry?

KlausVamberszky: Well,wehaveto differentiatebetween3differentkindsof “standards”:

• Realstandards,whichcomeoutofa “standardizationorganization”likeIEC, ISO,CIE,withexampleslikeLVD,EN 60598,EN12464.

• RegulationsanddirectivesoftheEuropeanUnion,likeSLRandELR,DPP, Reach,RoHS,butalsotaxonomyand PPWR,and–inaddition–nationalor evenregionalinstallationstandardsor rules.

• SpecialinterestgroupslikeDiiA,BTLE, Zigbee,Thread,Matter,industryconsortiawhichdefinerulesforinteroperability(Figure 5).

All3fieldsrequireattentionandresources,buttherisksofnon-compliance areverydifferent.So“standards”asa wholeplayagrowingrole,andtheyadd alotofcomplexitytothebusiness.

LEDprofessional: Docurrentregulatoryframeworkssupportinnovation, ordotheytendtoslowitdown?

KlausVamberszky: Yesandno.The banoftheincandescentlamp,thehalogenandfluorescentlampenhancedand supportedinnovationforsure.Onthe otherside,minimumenergyefficiency requirementsandthresholdsslowdown orevenforbidinnovationinnewlight sourceslikeOLEDsandLaserdiodes.

Buttheoverallcomplexityduetoallthe regulatoryframeworkexplainedaboveis risingfast,andcomplexityisTHEenemy ofinnovation.Innovationneedstobe focused,atleastintheearlystages,but withregardstoregulatoryframeworks thisdoesnotworkout.

Thisisoneoftheadvantagesof,forexample,theUSforinnovation:thefreedomtotryoutnewthingsismuchhigher thaninthesomewhatoverregulatedEurope.

Figure4: Fromenergyefficiencytoresourceefficiency–aparadigmshiftinprofessionallighting. Source:IECPresidentVihalMahendru;slideshownatÖVEInnovationDay2025(translated).Original source:Dr.TimMeyer,3EPunkt,Design:A.Timmins;LinkedIn.

Figure5: FragmentationofStandardsandinteroperabilityinitiativesinprofessionallighting.Source: ZumtobelGroupKlausVamberszky.

LEDprofessional: Whatroleshould Europeplayinthefuturedevelopment ofinternationallightingstandards?

KlausVamberszky: Europeshould playanimportant,ifnotaleaderrolein this,butthiswillmostlikelynothappen. Standardizationisinadifficultposition, especiallyinEurope.Standardization–atleastcontentwise-isnotdrivenby theassociationsbutbytheexpertsof theindustry.ButtheEuropeanlighting industryissuffering,decreasingpotential,turnoverandmargins.Andwewill runoutofresourcesforstandardization rathersoon.

Itwas,andstillisa“babyboomerbusiness”,anexpensiveexpertbusiness,includingalotoftravelling.Havingawide technologicalandapplicationoverview andknowledge,findingdifficultcompromises,beingdiplomatic,sortingposi-

tionsoutinalengthyandslownegotiationprocessisnotsomethingyoung peopleareveryinterestedin.

ThisisdifferentinChinaorevenIndia;it isdefinedbythegovernmenttoshape futurestandardsinfuture-orientated businessfields.Andtheypayforit, theyheavilysupportthisfromafinancialperspective.Theythinkinyears,if notdecades–notinquarters.Aninterestingexampleisgermicidallighting wherealmostallstandardizationactivitiesaredrivenoutoftheFarEast.Ifwe donotparticipateinanactivewaywe mighthavetoacceptstandardsweare notveryhappywithfromacontentpoint ofview.

LEDprofessional: Fromyourperspective,whatroledoesLight+Building playtodayforthelightingindustry?

LEDprofessional:Thedevelopmentof theSOLENAluminairefortheHortus SwitzerlandInnovationParkin Allschwilmarkedanimportantrecent milestoneforZumtobel.Whatmakes thisinnovationsodistinctive?

KlausVamberszky: Oneofitsdefining characteristicswastheuncompromising commitmenttosustainability.Thisambition requiredentirelynewapproachestoboth developmentandproduction,demandinga highlevelofinnovationandexpertise.This appliednotonlytoconstruction,butalsoto materialselectionandtheclose collaborationbetweentheexpertsat Herzog&deMeuronandReflexion. Achievinganecologicallyandeconomically viablelightingsolutiondependedonan interdisciplinary,agiledevelopmentprocess. Ourgoalwastocombinelightingprecision andefficiencywithahighlumen output—withoutglare,andwithmaximum functionalandaestheticquality.Theresult istheSOLENAglasstubeluminaire,which unitesasenseofsubtlebrillianceand refinedaestheticswithtechnicalprecision andoutstandingefficiency.Itrepresentsa truesymbiosisofsustainability,functionality, anddesign.

ImageCopyright:©IsabelBechter.

KlausVamberszky: Inmyview,althoughtradefairsarelosingimportance, Light+Buildingremainsakeyeventfor thelightingindustry.Itshowcasesthe evolutionoflightingfromastandalone producttoanintegralcomponentof sustainable,networkedbuildings.Most importantly,theinternationaldialogue betweenmanufacturers,plannersand technologypartnersacceleratesinnovationandensuresquality,helpingthe industrytakeontechnologicalresponsibilityanddeveloplong-term,sustainable solutions.Fromabrandperspective,visibilityinthemarketisalsoessential.You havetodemonstrateyourcompany’s values,andatradefairispartofthecustomerjourney.

LEDprofessional: Whichtopicsshould gainmorevisibilityatfutureeditions ofthefair—andwhichonesperhaps less?

KlausVamberszky: Show,explain, train,perceiveandexperiencethewide contentoflight.Nolongeraproduct show,butamixtureofsessions,conferences,ameetingpointbetweenscientificcommunity,targetgroupsandthe industryitself.Suchamodel,acombinationofaconferenceandatrade-show, sofarwasnotverysuccessfulinEurope, eveninotherbusinesses.Butwhynot giveitatryandmergeLICHTandthe Light+Building?

Itdefinitelymustnolongerbeapure productshow;thosetimeshavegone andwillnotcomeback.

LEDprofessional: Zumtobelpositioneditselfearlyasasolutionand systemsprovider.Whichdecisionsor developmentswereparticularlyinfluentialinshapingthisdirection?

KlausVamberszky: Well,thereare severalaspectstothis;firstofallthe founderfamilyZumtobel,with2generationsofengineers/technicianstorunthe company,thefounderDr.WalterZumtobelhimself,andlaterhistwosonsFritz andJürgZumtobel.Allbrandsofthe ZumtobelGrouparealwaystargetedto beinnovationandnotcost-leader.Then havingacomponentcompanywithTridonic,andnowtwolightingbrandswith ThornandZumtobelunderoneroof, helpedalot.Tocoverawidepartofthe valuechainisdefinitelyanadvantageif youwanttobeinnovativeandtooffera completesolution.Andintermsofsys-

temsandsolutionsproviderwecan’t forgetthevisionaryviewofDr.Walter Werner,themastermindbehindLuxmate asaclassicallightingmanagementsystem.

LEDprofessional: Howimportantare brandstrength,partnerships,and systemcompetenceforaninternationallyactivelightingmanufacturer today?

KlausVamberszky: Allveryimportant, butclosenesstocustomers,markets, targetgroups,applicationsareeven moreimportant.Thisalsoneedstobe mentionedincombinationwiththeanswerstothequestionbefore.

Youcan’tdoaprojectbusinessinEuropeoutofChina,andinfutureyouwill notbeabletodriveacircularlighting businessoutofAsiaforEurope.

LEDprofessional: Fromaleadership perspective,whathaschangedmost noticeablyinmanagingatechnology/ design-drivenindustrialcompany overthepastyears?

KlausVamberszky: Complexityand uncertaintyhavebeencontinuouslyincreasing,overthelastdecades.There arealwaysalotofpossibilities,mainly onthetechnicalside,buttheeconomic sideofitremainsunclear.Nowadays, itismuchmoreaboutrisktakingand managingthiscomplexity. Wherecanwebebetterthanthecompetitionandwheredoweneedtobedifferentfromthecompetition?Also,where dobothwaysnotpayoff?Strategyis alwaysaboutfocus,anditisatleastas importanttodecidewhatnottodoas wheretoconcentrate.

Additionally,costandoverheadmanagementismuchmoreimportantthan inthepastbecauseplayersfromtheFar Easthaveasuperiorcostposition,and amuchleanervaluechainasvertically integratedmanufacturers.

LEDprofessional: Lookingahead, whichissuesdoyoubelievewillmost decisivelyshapethelightingdomain inthecomingyears,andwhatadvice wouldyougivetothenextgeneration ofleadersenteringthelightingfield today?

KlausVamberszky: Inmybelief,the topic“lightandhealth”willbethemost

importantdevelopmenttowatchandto engagein.CEN/TC169hasjuststarted toworkonapart3ofEN12464regardingthenon-visualeffectsoflighting.Key willbetofindagoodcompromiseof visualandnon-visualeffectsinlighting installations,tosupportboththetaskin theapplicationandconsidertheamount oftimeusersspendattheirworkplaces underartificiallight.

Content-wise,Ican’timaginealotof businessesthataremoreinteresting thanlighting.Themixtureofarchitectureanddesign,mechanics,electronics, hard-andsoftwareandservices,physics andoptics,andnowmoreandmore biologicalandmedicalknowledgeisunmatchedandisTHEreasonwhyIhave stayedinlightingformorethan40years. Butnowadaysitisalsoaverychallengingindustry,withupsanddowns,with betterandworsetimes.Iwilldefinitely goonwatchingthedevelopmentsfor quiteawhile.

LEDprofessional: Thankyouvery muchfortakingthetimeforthisexclusiveinterview.

KlausVamberszky: Mypleasure. ■

The ZumtobelGroup isaleadinginternationallightingcompanyheadquartered inDornbirn,Austria,withalong-standing reputationforinnovation,quality,anddesignexcellenceinprofessionallighting. TheGroupdevelopsanddeliversholistic lightingsolutions,luminaires,lightmanagementsystems,andcomponentsfor demandingindoorandoutdoorapplicationsacrosssectorssuchasoffices, education,healthcare,industry,retail, andurbaninfrastructure.

Operatingthroughitsstrongandcomplementarybrands—Zumtobel,Thorn, andTridonic—theZumtobelGroup coversabroadportionofthelighting valuechain,fromhigh-qualityluminairesandadvancedcontrolsystems toLEDmodules,drivers,anddigitalsolutions.Thisintegratedbrandstrategy enablestheGrouptoprovidetailored, application-focusedlightingsolutions thatmeetdiversearchitectural,technical, andregulatoryrequirementsworldwide.

LightingDesignWithoutBorders: HowGlobalPerspectivesTransform Architecture–CarlaWilkins,IALDPresident

CarlaWilkins: “Lightingdesignisnotjustabout selectingluminaires—itisaboutdefining thearchitecturalidentityofaspace.”

CarlaWilkinsisoneofthefoundersofLichtvisioninBerlinandIALD President.Today,thefirmoperateswithseveralinternationaloffices, includingHongKongandShanghai.MarkusHelle,Editor-in-Chiefof HIGHLIGHT,metwithCarlaWilkinsinGuangzhou,China,duringthe GILEtradefairtodiscussday-to-dayplanninginaninternationalcontext, thevariousaspectsofglobalprojectwork,andhercommitmenttothe lightingdesignercommunitywithintheIALD.

lichtvision.com | iald.org

HIGHLIGHT: Fromaglobalperspective,doyouobserveculturaldifferencesinlightingdesignacrosscontinents?Orcansuchdistinctionseven beidentifiedonanationallevel?

CarlaWilkins: Lightingdesignandlightingconceptsindeedrevealculturaldifferences,whichweexperienceboth internationallyandnationally.

Thesedifferencesmaybeinfluencedby avarietyoffactors,includingclimate conditions,historicaldevelopments, technologicaladvancements,andculturalpreferences.Theidentityofaplace anditsclientisreflectedinthelighting solution—thisalsoappliesonanational level.InGermany,lightingdesigngenerallyrepresentsasymbiosisoftechnology,sustainability,anddesign.The Germanapproachtendstoberational andstandards-driven,butwithanincreasingawarenessoftheemotionaland culturaldimensionsoflight.

Aslightingdesignersgaingreaterinvolvementindiverseprojects,thedesign component—throughdeliberateuseof lightqualitiesandlightinghierarchies— becomesmorethantheselectionof decorativeluminaires.Itbecomesadefinitionofthearchitecturallightingidentity ofaspace.Sinceitsfounding,Lichtvisionhaspursuedthisgoal.

HIGHLIGHT: Whenyouworkonprojects inAsia,forexample,towhatextent areyourinternationalofficesinvolved alongsidethelocalteaminHong Kong?

CarlaWilkins: AprojectinAsiadoes notnecessarilyhavetobeanchoredexclusivelyinourAsianofficeifthecore projectteamhappenstobebasedin Europe.AtLichtvisionDesign,active collaborationacrossallofficesispart ofdailylife.Particularlyinlarge-scale projects,theotherofficescontribute throughdefinedworkpackages,knowledgeexchange,anddesigncharrettes. Weseeourselvesasoneteam—thinking globally,actinglocally.

HIGHLIGHT: Howwouldyoudescribe internalknowledge-sharingatLichtvisionwhenitcomestoprojectsand thelessonslearnedfromthem?

CarlaWilkins: Acrossalllocations, LichtvisionDesignholdsaglobalvirtualmeetingeveryweekwithallteam members.Duringthesesessions,workflowsandprojectsarepresentedand discussedinternationally.Everyvoiceis heard—therearenohierarchiesinthis format.Asaresult,ifneeded,further in-depthdigitalsessionsarearrangedin smallergroups.

HIGHLIGHT: Isitpossibletoimplementlightingdesignusinglocally sourcedluminairesandcontrolsystemsindifferentpartsoftheworld? Aretherespecificchallengesoradvantages?

CarlaWilkins: Implementingourlighting solutionsusinglocallysourcedluminaires andcontrolsystemsisgenerallyfeasible worldwideandcomeswithbothadvantagesandchallenges.

Amajoradvantageiscostefficiencydue toshorterdeliveryroutesandlowercustomsduties.Inaddition,locallymanufacturedproductsareoftenalready adaptedtoregionalclimateconditions, voltageinfrastructure,andapplicable standards.Localsourcingalsostrengthensregionaleconomiesandsupports sustainablevaluechains.

However,challengesdoexist.Insome regions,thequalityoflocallyavailable productscanvarysignificantly.Wehave anobligationtoourclientstospecify thebest,mosteconomical,andmost sustainablesolutions.Alackofskilled professionalsforimplementingcomplex lightingconceptscanalsobeanissue— thisiswhereinternationallyexperienced firmscanprovideessentialon-sitesupport.

Ourgoalisalwaystodeveloparobust solutionthatwithstandslocalimplementationchallenges.Thedecision betweennationalorinternationalsourcingisthereforeevaluatedindividuallyfor eachproject.

HIGHLIGHT: Sustainabilityisaubiquitousbuzzword,butitisinterpreted differentlyacrossregions.Where doyouseethedifferencesbetween EuropeandAsia?Andwhat,inyour view,shouldbethenextsteps?

CarlaWilkins: Sustainabilityisunderstoodandimplementeddifferentlyin EuropeandAsia,shapedbycultural,political,andeconomicframeworks.

InEurope,sustainabilityisvalue-driven andhighlyregulated.Thefocuslieson

long-termenvironmentalresponsibility, energyefficiency,andresourceconservation.Thisisreflectedinlightingdesign throughstricteco-designdirectives,an emphasisondaylightintegration,anda preferencefordurable,repairableproducts.Sustainabilityisseenasaholistic concept,interlinkingecological,social, andeconomiccomponents.

Lightpollutionhasbecomeacrucial globaltopicwithinsustainabilitydiscussions.Increasingawarenessamongdesigners,decision-makers,municipalities, andstandardsbodiesisessential.Balancingtheneedsofwildlife,vegetation, andpeoplemustbeapriority.Qualifiedlightingdesignersplayakeyrolein achievingthis.

InAsia,sustainabilityisoftentechnologydrivenandpragmatic.Manycountries relyoninnovationandscalability—forexample,throughthewidespreadadoption ofsmartlighting,massproductionofefficientLEDtechnologies,andintegration ofsolarandIoTsystemsininfrastructure.Ourjointvisitwithworld-architects toGILEinGuangzhoureflectedthis trend.Efficiencyandprogressarekey priorities,whilesocialandecological aspectsareincreasinglyaddressedas dedicatedlightingdesignteamsbecome moreinvolvedinprojects.

ForEurope,thenextstepsincludefurtherdigitalizationoflightingsystemsto enabledynamicenergycontrol,aswell asstrengtheninglocalproductiontoreduceemissionsfromsupplychains.In Asia,astrongeralignmentoftechnologicalsolutionswithsocialandecological sustainabilitygoals—forexamplethrough recyclinginitiativesorharmonizationwith internationalstandards—wouldbevaluable.

Bothcontinentscanlearnfromeach other:EuropefromAsia’sinnovative driveindigitalization,andAsiafromEurope’sholisticsustainabilityapproach.

HIGHLIGHT: Lichtvisionalsooperates atechnicaldivisioninadditiontoits designpractice.Howdidthiscome about,andwhatareitsresponsibilities?

CarlaWilkins: Lichtvisionwasfounded withtheideaofbringingpracticaldesignknowledgeintotheindustrywhile supportingdesignwiththetechnicalexpertiseofourengineeringteam.Initially

theconceptwassomewhatabstract, butaroundtheturnofthemillenniumthe DALIstandardemerged,andourengineeringteamenthusiasticallydelvedinto thisnewtechnology—initiallythrough contractdevelopmentprojects.

IndevelopingDALIproducts,mainly controlgear,werealizedthatDALIstill offeredsignificantroomforimprovement regardingstandardizationandquality assurance.Wethereforebecameactive intheZVEI,andmadeourinitiallyinternal testingdevicesavailabletothebroader market.Today,LichtvisionEngineeringis agloballeaderinDALIqualityassurance. EverydevicebearingtheDALI-2logo hasbeentestedandqualifiedwithour ProbitLab.

Morerecently,ourengineeringteam launchedProbitSite,aproductthatevaluatesthequalityofDALIinstallations andallconnecteddevices.Thisenables installerstocaptureevencomplexerrorsonsite,whichcanthenbeanalyzedbyexpertsatourdevelopment locations.Withtheriseofwirelesscommunicationstandardsinlighting,new projectshaveemerged—forexample, integratingsensorsandothercontrol elementsintoopenstandardssuchas Wi-Fi,Bluetooth,orproprietarysystems likeCasambi.

Becausetheengineeringteamislocated inthesameofficeastheBerlindesign team,bothbenefitfromsharedexperienceandlessonslearned.

HIGHLIGHT: YouarecurrentlyPresidentoftheInternationalAssociation ofLightingDesigners(IALD)andwill assumethepresidencynextyear. Whatareyourgoalsforthelighting designcommunitylocallyandglobally?

CarlaWilkins: AsIALDPresident,Isee myfutureroleasstrengtheningtheinternationallightingdesigncommunitywith thevision:thinkglobally,actlocally.With morethantenyearsofinvolvementin theIALDandasGlobalCreativeDirector atourinternational,independentlighting designfirm,Iamwelltrainedtounderstandthediversityofourprofession— culturally,economically,andcreatively.

TheIALDisundergoingatransformationinitiatedbythe2023vote.Mygoal istofurtheranchorthischangeinthe organization’sday-to-dayoperations

and,togetherwiththetaskforcesand headquarters,buildastable,transparent,andfuture-orientedstructure.Key prioritiesincludefinancialconsolidation, clearcommunication,andfosteringa strengthenedsenseofcommunity.

IALDhasopeneditsdoorsbeyondthe circleofindependentlightingdesigners, creatingopportunitiesformembership forlightingdesignersinindustry,lighting enthusiasts,mediadesigners,andother creativeprofessionalsworkingwithlight.

Forlightingdesignersworldwide,Iwant tomakethebenefitsofIALDmembershipmorevisible—throughexpanded networking,targetedprofessionaldevelopment,andastrongerpresencein theinternationallightingcommunity.The impressiveparticipationinlocalchapters andinthemostrecentelectiondemonstrateshowcommittedourcommunity is.Ihopetofurtherencouragethisengagementonaglobalscale.

InGermany,the“GermanIALDChapter”iscoordinatedbyPhilipRafael,Carla Jardim,RezaJalalzadeh,andStephan Horn,whoarealreadybringinglighting designers,lightingenthusiasts,andthe industrytogetherthroughvariousformats.Iseemypresidencyasanopportunitytocombinecontinuitywithchange. TheIALDshouldbeastronginternationalvoiceforlighting—withanopen, inclusivemindsettowardallstakeholders.

HIGHLIGHT: Thankyouverymuch fortakingthetimeforthisexclusive interview.

CarlaWilkins: Mypleasure. ■

AboutCarlaWilkins: Followingher trainingasanarchitect,CarlaWilkins workedatindependentlightingdesign firmsinNewYorkCity,Cologne,and Berlin.AtLichtvision,sheisresponsible forconceptsandplanning,andoversees globaldesign.Shehasbeenaboard memberoftheInternationalAssociation ofLightingDesigners(IALD)formore thantenyearsandcurrentlyservesas President.Sheisalsoaprofessional memberoftheWerkbundBerlinand isactiveinpromotinglightingdesign throughlecturesandindustryengagement.

Photocredits:MesseFrankfurtHK

TheRoleofLEDLightinginClimate Change

Dr.J.NormanBardsley,ChiefAnalystattheInternational Solid-StateLightingAlliance

ProponentsforLEDlightinghave hopedthatthegaininefficiencywould compensateforthegrowthinthedemandforartificiallightingandsoreducetheimpactoncarbonemissions andglobalwarming.Thisarticlereviewsthetechnologicalprogressmade since2000andsurveysthestateofthe lightingindustryin2025.Suggestions aremadeforfutureR&Dthatcould leadtoevengreaterimprovementsin efficiency.

EachyeartheInternationalSolidState LightingAlliance(ISA)publishesareport onthestatusoftheindustrywithanemphasisontechnicaldevelopments.The 2025edition [1] providedanopportunity tolookbackoverthepast25yearsofLED developmentaswellastosummarizethe dataonrecentcommercialactivity.

TheHistoricalPerspective

Theopportunitiesforsubstantialreductions intheuseofelectricityforlightingthrough theadoptionofSSLwerepresentedin “Light’sLabour’sLost:PoliciesforEnergyefficientLighting” [2].TheIEAestimated thatin2005theglobalproductionofartificiallightwas135petalumen-hours(Plmh), consuming2651terawatthours(TWh)of electricity,equatingtoanaverageefficacy ofapproximately50lm/W.

Concernabouttherapidgrowthinelectricitydemandforlightingpromptedgovernmentsaroundtheworldtoinvestin R&Dprogramsonsolid-statelighting (SSL).TheseinvestmentsledtoLEDlightingbecomingthedominantgloballight source.Today,nearly20yearsafter Lights, Labour’sLost,theglobalaverageefficacy oflightinghasroughlydoubledtoapproximately100lm/W.

Despitetheseimprovements,determiningthecurrentglobaldemandforartificial lightremainschallenging.Inflation-adjusted globalGDPincreasedbyafactorof2.3 between2005and2024,whilesatellitebasedanalyses [3] showthatglobalnighttimeemissionshavegrownevenfaster.

Basedonthesetrends,ISAestimates globallightproductiontoexceed350Plmh peryear,implyingglobalelectricityconsumptionforlightingofapproximately 3,500TWh,orabout12%oftotalenduseelectricitydemand.

Importantly,asignificantshareofthis growthreflectsrisingdemandforlighting servicesinregionsexperiencingincreased economicprosperity.Incontrast,inmature markets,bothaggregateelectricityconsumptionforartificiallightinganditsshare oftotalelectricityusehavedeclined.

ThesubstantialprogressinLEDtechnologyhasledgovernmentstodeclaresuccessintheirenergy-efficiencyprograms forlighting.IntheUStheDoEhasclosed itsSSLR&DinitiativeandtheHorizonresearchprograminEuropehasreducedthe numberofprojectsonlighting.InChina, supportforR&Donwide-bandgapsemiconductorsisstillstrongbuttheemphasis hasmovedfromlightingtootherapplications,suchasmobileelectronicdevices andAIdatacenters.

TheNGOsconcernedwithenergyefficiencyhavealsoreducedtheirinvolvement inlighting.InMay2025CLASPannounced theconclusionofitsCleanLightingCoalition [4].ThescopeoftheGlobalOff-Grid LightingAssociation(GOGLA)hasbeen expandedtoincludenon-lightingapplicationsofoff-gridsolarenergy [5].Withinthe lightingindustry,somecommentatorshave suggestedthepriorityfornewdevelopmentshouldmovefromefficacytoquality oflight.

ISAisconcernedaboutthesetrendsfor tworeasons.First,thedemandforartificiallightiscontinuingtogrow,asother countriesfollowtheexampleofChina. Thelightingindustryhastheopportunitytocontributefurthercost-effective energysavingsthroughLEDtechnology andcontrols.Secondly,thegreatergains inLEDefficiencyhavecomemainlyfrom improvementsinsourcesofbluelight.To enabletherealizationof“human-centric” lightingandefficientdisplays,substantial efficacygainsareneededatgreenand

amberwavelengths.Despitetheamazing developmentofflat-paneldisplays,there areveryfewdisplayswithawall-plugefficiencyover10%.AlmostallLEDdisplays areilluminatedbywhiteorbluelight,most ofwhichisabsorbedinsidethedisplay. OLEDpanelshavedemonstrateddirectemissivedisplaysusingRGBlightatthe sub-pixellevelandinorganicLEDsystems needtofollowtheirlead.

Oneoftheconsequencesofreducedinterestbygovernmentsinlightingefficiency isthatthereislittledataonthecurrentdemandforlightingortheconsumptionof electricity.Forexample,themostrecent informationintheIEAenergytrackingprogram [6] isfor2022.TheIEAdatadoes notincludeoutdoorlightingandseemsto underestimateuseinChina.Anattempt tofillthisgapisbeingmadebytheIEA 4ESmartSustainabilityinLightingand Controls(SSLC)Platform [7,8] whichisfocusingitsactivitiesonsmartlightingand controlsandfollowsqualityandefficiency ofLEDlightingthroughproductdatabases andmeasureddata.

TheEfficacyofLEDLights

Theavailabledataoncurrentproducts suggeststhatimprovementsinLEDperformanceareslowing.TheEuropeanProductRegistryforEnergyLabelling(EPREL) databasegathersdataonlightingproducts soldintheEU,includinggenerallighting service(GLS)lamps [9]

Table 1 showsthatthedistributionof thelampsintheregistryatfourdates since2022.Moststillhaveefficacybelow110lm/Wandthattheproportionin thetopthreegroupshasrisenonlyslowly since2022.

Theproductsremainintheregistryuntil theyaretakenoffthemarketandsome legacyproductsareincluded.TheIEA4E SSLCPlatform [8,9] hasseparatedthe lampsintheEPRELdatabasebyyearof introduction.

Figure 1 showshowthedistributionin claimedefficacyofnewGLSLEDlamps hasevolvedoverthepastsixyears.

Table1: Evolutionoftheefficacydistributionof thelightingproductsintheEPRELregistry.

Theboxplotin Figure 2 showstheevolutionofthepercentiledistributionofluminousefficacyforGLSLEDlampsinthe EPRELdatabaseovereachmarketintroductionyear.Althoughthemedianefficacy hasrisenbyabout4lm/Wperyearsince 2021,theannualimprovementatthe20th percentilehasbeencloseto1lm/W.

TheupcomingreportbytheIEA4ESSLC Platformwillgivemoreinformationonthis dataandsetitinabroadercontext [10]

Thedistinctionbetweentheratesofefficiencyimprovementsinthelowerperformanceclassesisofspecialconcern becauseofthesubstantialdifferencein price.ThedataintheEPRELdatabase takesnoaccountoftherelativesalesof eachmodel.AninformalstudyofthebestsellingomnidirectionalLEDlampsavailable atthemajorhardwarestoresinCalifornia atthebeginningof2026showsamedium efficacyof91lm/Wwithnolampsoffering morethan100lm/W.In2024DOEfinalized amendedstandardsthatwoulddramaticallyraiseefficacyformostomni-directional lampstoover120lm/WforthosemanufacturedorimportedonorafterJuly25,2028. However,itseemsdoubtfulwhetherthis regulationwillbeenforcedbythecurrent administration.

Theefficacyoflightingproductsinthe commercialandmunicipalmarketshas improvedmorerapidly.IntheUS,the DesignLightsConsortiummaintainsrecommendedperformancestandardsfor awiderangeofproducts.Forexample, since2020theminimumstandardefficacy formostoutdoorlightingproductshas been105lm/Wandthatforindoortroffers (ceilingluminaires)was110lm/W.From January2026theselevelsarebeingraised to125lm/Wforstreetlightsand120lm/W fortroffers.

ThepublishedDLCdata [11] makesiteasiertotracktheefficacyimprovementinthe productsthatqualifyeachyear. Figure 3 showsthetrendsintheefficiencyofpolemountedstreetlightsatthe75th,50th and

Figure1: EnergylabeldistributionofGLSlampsintheEPRELdatabasebyyearofmarketintroduction(IEA 4ESSLCPlatform).

Figure2: PercentiledistributionofluminousefficacyofGLSLEDlampsintheEPRELregistryasafunction ofthemarketintroductionyear.

Figure3: Changeofluminousefficacyatthe25th,50th

theDLCdatabase.

25th percentileswhenrankedbyefficacy. Thesedatashowthatalthoughtheefficacy ofthemostefficientlampshasimprovedat about2lm/Wperyear,thatofthepoorest hashardlychanged.

Thecorrespondingdatafor2x4troffersis shownin Figure 4.Inthiscase,theannual increaseinefficacyhasbeen ∼2%atall threelevels.

Thedatapresentedabovesuggestsstrongly thatfurthereffortisrequiredtoimprove manufacturingprocessesaswellasthe underlyingtechnology.Attheepitaxial level,tightercontrolisneededinprocess windowstoreducethewiderangeinperformanceseenfromLEDsemergingfrom eachmanufacturingline.Overthewhole supplychainwaysshouldbefoundtoreducethepricedifferentialthatishindering theadoptionofefficientlightingproducts.

TheGlobalLightingMarket in2025

ThedemandforLEDsgrewrapidlyinthe decadeupto2020buthasslowedas nearlyalltraditionallightshavebeenreplacedandtheextendedlifeofLEDdevicesreducestheneedfortheirreplacement.TherevenuesandprofitsoftheleadingmanufacturersofLEDchipsorpackagesaresummarizedin Table 2.

AllmanufacturersoutsideChinahave struggledtomaintainrevenuesormake anynetprofits.Nichiadoesnotrelease dataonitsLEDsales.Little,ifany,informationhasbeenreleasedabouttherevenues ofLumiledsin2025,butsalesin2024 wereestimatedtobe ∼USD600million, wellunderhalfofthoseinthePhilipsera. CreeLEDsarenowproducedbyasubsidiaryofPenguinSolutions.Revenuesin FY2025wereessentiallyflatatUSD256 million,whileoperatingprofitincreased fromUSD2.5milliontoUSD9million.

WithinChina,HCSemitekhasbenefited frommajorcapitalinvestmentsfromBOE andthesubsequentfocusontheproductionofmini-andmicro-LEDsfordisplays. San’an’scontinuedgrowthhasbeenaccompaniedbyanincreasedproportionof salesonotherapplicationsofcompound semiconductors.

Movingdownstream, Table 3 summarizesthefinancialresultsofsomeofthe majorsuppliersoflightingproducts.The resultsforAcuityandZumtobelareforthe 12monthsendinginAugust2025andOctober2025,respectively,whiletheothers arefor2025calendaryears.Theresultsfor

Changeofluminousefficacyinthe25th,50thand75thpercentilefor2x4troffersintheDLC database.

Table2: RevenuesandprofitsofLEDmanufacturersinfirst9monthsof2025and2024.

Table3: Revenuesandprofitsofmajorlightingcompaniesin2025.

AMS-OsramarefortheLampsandSystemsDivision.

ThegrowthinthesalesofAcuityBrands hascomemainlyfromtheirIntelligent Spacessegment.Mostofthegainsat EndoLightingwerealsoduetocontrol systems.Alltheothercompaniesshowdeteriorationinbothsalesandprofits.

IndiaisstillexperiencinggrowthinthedemandforLEDlighting. Table 4 compares companyresultsforthefirsthalfofthefiscalyear,2025(April-September)withthe correspondingperiodin2024.Mostofthe

companiesareshowingimprovedprofitability.

Table4: RevenuesandprofitsofIndianlighting companiesincrores.

ThetransferofLEDmanufacturingcapacitytoChinahashadmajorimplicationsfor equipmentmanufacturers.Inthefirst9 monthsof2025,only14%ofthe290M euroequipmentrevenuesofAixtroncame fromtheLEDsegment,while66%were generatedwithequipmentforpowerelectronicsbasedonGaNandsiliconcarbide SiC.Inthesameperiod,Veeco’stotalrevenuesfromcompoundsemiconductors wasonlyUSD39million,downfromUSD 55millionin2024andUSD96millionin 2022.Meanwhile,theoperationsofAdvancedMicro-FabricationEquipmentof China(AMEC)havegrownrapidly.Revenuesinthe12monthsendinginJune 2025were11.6Byuan,upfrom9.1Byuan incalendaryear2024and6.3Byuanin 2023.In2024AMECreceived4.9Byuan ingovernmentsubsidies,enablingittoreportnetincomeof1.9Byuan.

SSLinChina

TheChinaSolidStateLightingAlliance (CSA)estimatesthatChina’sshareofthe globallightingmarketisnowover75%. Therearethousandsofmanufacturersof LEDsorLEDproducts,andthetop100 companiesproducelessthanonethird oftotalrevenues.Thus,itisimportantto followthewholeindustryinChina.The CSA‘bluebook’providesagoodwayto dothis [12].

CSAestimatesthatthetotaloutputvalue oftheLEDindustryin2025fellby1%to 609Byuan.Chipproductionwasdown by11%to27Byuan,whilethepackaging segmentfellby2%to77Bandsalesof LEDproductswasstableat506Byuan. Figure 5 showsthetrendinthesethree segmentssince2014.

Revenuesinthegenerallightingmarketfell by11%to213Byuan.Thisreductionwas balancedbyincreasedsalesinspecialty markets,suchasdisplays,automotive, horticulture,UVLEDsandsmartsystems.

Inthefirstthreequartersof2025,LED companieslistedonthemajorstockexchangesachievedacumulativeoperating incomeof141Byuan,ayear-on-yearincreaseof6.2%;however,thetotalprofit

fellby3.6%to10.1Byuan.56%ofthe companiesreportedrevenuegrowth,but only47%ofthecompaniesachievedprofit growthandnearly30%sufferedlosses.

AccordingtodatafromtheGuangyaLightingResearchInstitute,fromJanuaryto November2025,thevalueofChina’sLED lightingproductexportsfellby7.2%toUS $35.1B.Thereductionwasmainlydueto fallingprices.Forexample,althoughthe totalexportvolumeofLEDlightsource products(bulbs,tubesandmodules)rose by37%to14.8B,thevaluedecreasedby 11%.LEDproductsaccountedfor78%of alllightingexportsfromChina.Partofthe remainderwasduetoasurgeinthesaleof halogenlampsinVietnamandCambodia.

ExportstotheUSfellby22%whilethose toEuroperemainedstable.Eachregion nowconstitutesabout20%oftheglobal total.ExportstoASEANregionsincreased, partlydrivenbyan82%riseinLEDmodulessuppliedtofactoriesestablishedby ChinesecompaniesinotherAsiancountries.

OpportunitiesforFurther ResearchonEfficiency

Furtherresearchwillbenecessaryifthe lightingindustryistomakeasubstantial contributiontothereductionincarbon emissionsandremovetheconflictbetween maximumefficiencyandlightquality.The achievementsthathavebeenmadeinblue andredemittersshouldbereplicatedover thefullrangeofwavelengthsandinmicroLEDs.Inaddition,newmanufacturing techniqueswillberequiredtoreducethe differentialincostbetweenthemostand leastefficientlightsonthecurrentmarket.

Perhapsthemostcriticalchallengefor generallightingistofillthegreengap.Althoughhighefficacyhasbeenachievedat lowcurrents,itdropsrapidlyascurrentis increased. Figure 6 showstheanalysisof thisdroopmadebyresearchersfromthe UniversityofIllinois [13]

CausesofdroopingreenLEDs.

Manygroupshavetriedtoreducethe droopusingvariousformsofGaNorGaP devices,whileothershavesuggestedradicallydifferentapproachesusingquantum dotsorperovskites,butnosolutionhasyet beendemonstrated.

MostcurrentUVlampsfordisinfectionstill useplasmadischargeswithmercury.LED sourceshavemadesomemarketpenetrationatwavelengthsaround280nm,but theirefficiencyisstilllow.Emissionnear 222nmhasadvantagesforaircleaning, whileVUVsourcesbelow200nmhasspecialvalueforwaterdisinfection.Further R&DisneededifLEDsourcesarealsoto dominatethesemarketsandreachingbelow200nmisaformidablechallenge.

Thereareveryfewdisplayswithefficiency above5%.Thebasicproblemininorganic LEDdisplaysisthatinordertocreatevivid images,mostofthelightcreatedinthe backlightisabsorbedwithinthedisplay.

OLEDdisplayshavedemonstratedthatthe desiredlightcanbecreatedwithineach sub-pixel,butextractingthelightisdifficultandnewblueemittersareneeded. SomeprogresshasbeenmadeinLED displaysthroughtheuseofmini-LEDsin segmentedbacklights.Deployingindividual sourcesatthesub-pixellevelformedium andlargesizedisplaysrequiresLEDsof around0.1mm.Gainsinefficacyarerequiredatthosesizesandefficientmeansof defect-freetransferfromthemanufacturing substrateneedtobedeveloped.

Thedatapresentedaboveshowthatthe industrycannotaffordmajorincreasesin spendingonR&D.Despitethereductionin supportfromgovernmentsoutsideChina, thereisstillahealthyacademiccommunity involvedinlighting,asevidencedbythe recentLS2025conferenceinTunisia [14] However,theacademiccommunitydoes nothavetheresourcestotacklethecore issuesdescribedherewithoutrenewed coordinationwithindustrysupportedby governmentprograms.

Conclusion

Thegoodnewsisthatlighting’sshareof globalelectricityusehasfallenfromapproximately19%in2000toabout12% in2025.Thebadnewsisthatitsconsumptionhasgrownfromapproximately 2,650TWhtoabout3,600TWhoverthis period.Iflightingistomakeamajorcontributiontotheameliorationofglobalwarming,furtherR&Donefficiencywillbeneeded. Thiswouldrequirecontinuedsupport fromgovernmentsandNGOsacrossthe globe. ■

Acknowledgements

TheauthorisgratefultoGillianIsoardiPhD, CarstenDam-HansenPhDandMichael ScholandLCregardingthedataandother inputforthisarticleontheworkoftheIEA 4ESSLCPlatform.

TheInternationalSolidStateLightingAlliance(ISA) isaglobal,non-profit organizationdedicatedtopromotingthe developmentandadoptionofsolid-state lighting(SSL)technologiesworldwide.ISA bringstogetherkeystakeholdersfromindustry,research,standardizationbodies, andpublicinstitutionstofosterinternational cooperationandknowledgeexchange.

ISAfocusesonadvancingenergy-efficient, high-quality,andsustainablelightingsolutionsthroughpolicydialogue,technicalcollaboration,andthedisseminationofbest practices.Theallianceactivelysupports harmonizationofstandards,markettransformationinitiatives,andcapacitybuilding acrossregions,contributingtoglobalenergyefficiencyandclimategoals.

Byservingasaneutralinternationalplatform,ISAfacilitatescollaborationbetween governments,industryleaders,andexperts toaccelerateinnovation,improvelighting quality,andsupportthetransitiontoward sustainablelightinginfrastructuresona globalscale.

isa-world.org

AbouttheIEA4ESSLCPlatform

TheIEA4ESolidStateLighting(SSL)Annexwasestablishedin2010underthe frameworkoftheInternationalEnergy Agency’sEnergyEfficientEnd-useEquipment(4E)ImplementingAgreement.Its purposehasbeentoprovideadviceto itsmembercountriesseekingtopromote energy-efficientlightingandtoimplement qualityassuranceprogrammesforSSL lighting.InMarch2024,theSSLAnnex renameditselftheSmartSustainabilityin LightingandControls(SSLC)Platformin recognitionofthesignificantopportunity foradditionalenergysavingsthroughsmart lightingsystemsandcontrols.

MembercountriesandeconomiesparticipatingdirectlyintheworkoftheSSLC PlatformincludeAustralia,Denmark,the EuropeanCommission,France,theRepublicofKorea,SwedenandtheUnited Kingdom.

www.iea-4e.org/ssl/

Dr.J.NormanBARDSLEY,Founder andSSLAnalyst,BardsleyConsulting Dr.J.NormanBardsley,adistinguished ProfessorofPhysics,hasearnedinternationalacclaimasanexpertinsolidstatelighting(SSL)throughhisadvisory roleswiththeDepartmentofEnergy(DoE) andtheInternationalSSLAlliance(ISA). Renownedforhisextensiveandnuanced understandingofOLEDtechnology,Dr. Bardsleypossessesacomprehensive graspofitsmanufacturingprocesses,cost structures,andongoingresearchendeavors.

jnbard@pacbell.net

References

[1] http://www.isa-world.org./Index/show/catid/56/id/4 46.html

[2] https://www.oecd.org/content/dam/oecd/en/publi cations/reports/2006/06/light-s-labour-s-lost_g1gh 5b98/9789264109520-en.pdf

[3] https://www.nature.com/articles/s41597-024-042 28-6

[4] https://www.clasp.ngo/updates/concluding-clic/ [5] https://gogla.org/

[6] https://www.iea.org/energy-system/buildings/lighti ng

[7] https://www.iea-4e.org/wp-content/uploads/2025/ 02/SSLC-Platform-Presentation-EEDAL-2024-Kitak yushu-Japan.pdf

[8] https://hal.science/hal-04661494v1/file/SCHOLAN D%20-%20SSLC%20Platform%20Overview%20for %20BRICS-ISA%20Conference%20in%20Shenzhe n%2C%20China%20v2.pdf

[9] https://eprel.ec.europa.eu/ [10] DraftreportbytheIEA4ESSLCPlatform,tobe publishedon https://www.iea-4e.org/ssl/news/ [11] https://designlights.org/qpl/

[12] https://www.china-led.net/news/202601/08/5514 6.html

[13] https://www.semiconductor-today.com/news_item s/2025/jun/uiuc-120625.shtml

[14] https://ls2025monastir.com/program-schedule/

ReportontheIEEESustainable SmartLightingWorldConference, LS2025

StuartMucklejohn,Secretary–LS2025InternationalScientific Committee

TheIEEESustainableSmartLightingWorldConference(LS2025),see: https://ls2025monastir.com/1,washeld 08to10December2025inMonastir, TunisiahostedbytheUniversitéde MonastirincollaborationwithIEEE andtheSmartCitiesTechnicalCommunity.

Thismeetingmarkedthe50thanniversary ofthefirsteventintheLSserieswhich beganastheSymposiumonIncoherent LightSourcesheldatLoughboroughin April1975.

FollowingtheopeningceremonyandwelcomefromGeorgesZissis,ChairoftheInternationalScientificCommittee,Boutheina Abassigaveherpresentation‘Illuminating themind:Lightandmentalhealthfrom circadianrhythmstotherapeuticapplications’.Thishighlightedtheimportanceof lightandlightingbothforthephysicaland mentalhealthofhumans,particularlythose whospendmuchoftheirtimeindoors.

KamelCharrada,Vice-President-UniversitédeMonastir,introducedthepanel discussionon‘Humanitarianactionsfor lighting’.Thecontributorswere:Georges Zissis(France);TobyCumberbatch(USA); HichemAmri(Tunisia);LambrosDoulos (Greece);LaurentCanale(France).This highlightedtheplightoftheapproximately 1.3billionpeoplewhodonothaveaccess toamainselectricitysupply.Thislackof infrastructurehasamajorimpactontheir abilitytobenefitfromelectriclighting.Eithereducationalstudiesandproductive industrystopsatsunsetorartificiallightingfromfuelssuchaskerosenehaveto beused.ThesedifficultiescanbealleviatedbyLEDlightsourcesbuttheseare stilldependentonareliableelectricitysupply.Lead-acidbatteriesarenotsuitable forsuchapplications,solarpoweredbatterypacksareidealbutwidespreaduseof thiscombinationneedsmuchmorefunding.Locally-basedmicrogridsforelectricity suppliesareprobablythebestsolution.

1https://ls2025monastir.com

Thepanelstressedtheimportanceoftwo otherfactors:systemsmustbehighlyreliableotherwisetheywillnotbeused;there isapressingneedtoeducategovernments andthepublicabouthowbesttouseartificiallighting.

NozomuYoshizawaposedthequestion ‘Whydoweusetotallydifferentmetrics andmethodsforevaluatingvisualeffects?’. Forexample,themetricsforevaluating glarefordaylightthroughwindowsarenot thesameasthoseforsmalllightsources. Hewentontooutlinemethodstocharacterizescenesbasedonneurophysiological modelswithedgedetectionalgorithms. Thesizeofthevisualtargetandchromaticitydifferencesaswellasluminanceare importantinputstosuchmodels.

Thesymposiumthenhadtwoparallelsessions–‘Visualandnon-visualeffectsof light’and’Lightapplications&societal impacts’.IntheformersessionStefanKällbergsummarizedastudyofSwedishdata fornighttimetrafficaccidentsandtherole ofheadlampglare.Thishasrecentlybecomeawidelyrecognizedproblemand thetopicofmuchconcern.Probablereasonsforthisinclude:higherluminance fromLEDheadlamps;ashifttolampswith morebluelightcontent;highermounting heights,especiallyonSUVs,crossovers &pickups;anageingpopulation;reduced roadlightingforenergysavingreasons;optimizedLED-lampsaremoresensitiveto misalignment;adaptivedrivingbeamsystemsnotfunctioningproperly.Fromtheir analysestheauthorsdrewtentativeconclusions:increasedglareannoyancedoesnot necessarilyleadtomoreaccidents;only ∼0.1%ofallaccidentsarecausedbyglare fromothervehicles;glarefromthesunisa morecommonfactor.However,themost importantfindingwasprobablythat‘Modernheadlampslikelymakeyourvisibility betterbutmakeotherdrivers’visualcomfortworse’.

DuringthelattersessionZouaghi etal. detailedsupplychainstrategiesforsus-

tainableandresilientlifecyclemanagement ofsmartlightingsystems.Keyfactorsto asuccessfulsystemincludebeingableto reliablypredicttheneedforreplacement itemsandtoensurewarehousesholdthe necessarycomponents.Predictingfailure ratesforLEDdriversbyPrestonandMucklejohncomplementedthepreviousstudy.

Twopapers,byNovak etal. andMokni et al.,addressedthecausesoflightpollution inurbansurroundings.Inbothexamples, streetlightingprovednottobethedominantsourceoflightpollution,themain contributorsbeingbillboardsandunshaded windows.Raniaandhercolleaguespresentedasmartlightingstudyofanurban greenspace.Tobesuccessfullightingfor theseareasmustbediscretelypositioned toavoidglare,haveawarm etal. temperatureand,ideally,solarpowered.

VéroniquePerruchonoutlinedherthoughts onhowtogetthebestfromLEDsforstage lighting,itisnotsomuchthecolorofthe sourcethatisimportantforthetheatre audiencebuttheappearanceoffabrics andcostumes.

ErkkiIkonenopenedtheafternoonsession withhiskeynoteaddressonphotometric measurementsbasedonconefundamentalswhichrelatetotheresponsesoftheS, MandLconesintheretina.Thischange wouldhaveimplicationsforreportingthe parametersofcommerciallyavailablelight sources.Changingfromasystembased ontheCIE V (λ) function,i.e.valuesof spectralluminousefficiencyforphotopic vision,toonebasedonanewfunction, Vf (λ) wouldcauseconfusionunlessthe transitionwascarefullymanagedovera periodofmanyyears.Thesepotentialdifficultiesgeneratedconsiderabledebate withintheaudience.

Followinganinteractivepostersession participantsheadedforaguidedtourof thecityofMonastirwiththesettingsun providingabeautifulbackdroptotheribat anditssurroundings.

TheseconddayopenedwithAnneBerends givinganoverviewoftheimportanceof near-IRtomaintainhumanhealthand topromotehealing.Near-IRisacomponentofsunlightbutislargelyabsent fromindoorenvironments,thishasbeen morenoticeableintheeraofLEDlight sources.Researchsincethe1960shas shownnear-IRradiation:reducesinflammationandaccelerateswoundhealing; hasbeenapprovedbytheFDAforpain reliefincasesofhead&neckpain,arthritisandcarpaltunnelsyndrome;become therecommendedstandardcarefororal mucositis.Near-IRisnowbeingusedto promotebonehealingindentistry,healingdiabetes-inducedwoundsandtotreat retinaldiseases.Indoorlightingcanbe supplementedbynear-IRLEDsources (www.sunbooster.health)toredressthe balanceofthemissingcomponentsinnaturallight.

MariaNilsson-TengelinsummarizedtheinitialfindingsfromtheSwedishcohortevaluatingtheuseofwearablelightloggers, thisislinkedtoawiderstudy(theMeLiDosproject)onthenon-visualeffectsof light.Thesephenomenaincludecircadian rhythmdisruption,impactonmoodand alertnessandlinkstootherhealthissues. Recruitingsubjectstoweartheloggers proveddifficultbutthosewhodidagree tobepartoftheearlystudydidcomply withthedisciplineneededtocollectreliable data.Improvementstothedesignofthe loggershavebeenidentifiedtohelpmake themmoreconvenientfortheparticipants.

GraemeListerillustratedthatbotholdand newlightsourcetechnologiesareplaying importantrolesinairandwatersterilization processes.VacuumUVradiation(VUV), i.e.wavelength<200nm,isusedforwatertreatment.Thiscanbegeneratedby fluorescentlamptechnologytoproduce 185nmradiationfromMercuryatoms, whilenewerthenewertechnologyemploysmicro-plasmadevicesfor172nm and197nmradiationfromexcitedXenon dimers.AlthoughMercury-Raregasdischargeshavebeenstudiedformanyyears, mostoftheefforthasbeenconcentrated on254nmradiationforfluorescentlamps andthereismoreresearchneededtounderstandthebestwaytogenerate185nm radiation.

Micro-plasmadevicesarealsousedto generate222nmradiation(far-UVC)forair sterilizationfromKrClexcimers.

OctavioPérezgaveamasterlyreviewof sportslightingconcentratingonthemost recentrequirementstomeettheneeds ofmulti-nationalbroadcasters.Televising

sportseventsisahugeeconomicdriver whichgenerated>160billionUSDin2024. However,sportslightingisalsoimportant atthecommunityleveltohelppromote exerciseandsocialengagement.

Formajorfootballmatches,goallinetechnologyandrelatedsystemshaveplaced additionaldemandsonlighting.Theappropriateilluminance,colortemperature, uniformityandtheavoidanceofglareare vitalnotonlyforthecamerasandtelevision audiencesbutalsofortheplayers.

Theyear2025markedthepassingofJohn Waymouth,oneofthefoundersoftheLS series.Johnwasagiantoflightingand lampresearch,hewasagreatadvocate forallaspectsoflightingeducationand hadatirelessenthusiasmforsharinghis knowledgeandenthusiasmwiththose newtothelightingcommunity.Graeme ListergaveatributetoJohnduringthe symposiumdinner.

Thefinaldayofthesymposiumstartedwith RichardCaratti-Zarytkiewiczaddressing lightingdesignforart,architectureandtheatreinitsvisualandnon-visualdimensions. Hepaidparticularattentiontothevisual fieldoftheobserverdividingthisintothe central,near-,mid-andfar-peripheralregions.Hehighlightedastunninglighting displayofLeonardoDaVinci’s‘Ladywith anermine’wheretheattentionisdrawnto thepicturebyablackbackgroundcovering allbutthecentralpartoftheobserver’svisualfield.

TobyCumberbatchintroducedtheIEEE ‘Let’sMakeLightCompetition’(letsmakelight@ieee.org)byhighlightingagainthe plightofthosemanymillionsofpeoplewho donothaveaccesstoareliableelectricitysupplybysimplyasking‘Whoarewe talkingabout?’Thesepeoplearepredominantlysubsistencefarmerslivinginpartsof Africa,IndiaandSouthAmerica.Tomove outofthecircleofpovertyeducationiskey, especiallyforwomen.Readyaccessto electriclightingenablesstudytocontinue beyondsunsetinsafeconditions.

Thechallengeforthoseenteringthecompetitionistoshowtheyunderstandthe importanceofbothengineering,business andthesynergyneededbetweenthese twodisciplinestoensuresuccessfuland sustainableenterprises.The2026competitionopensinJanuary.

Tobyclosedhispresentationbyreminding theaudience-‘Peopledonotunderstand poverty’.

Inhiswide-rangingsurveyLambrosDoulos reviewedhisthoughtsonaholisticapproachtolightingdesign,engineeringand intelligence.Hestressedtheimportanceof payingattentiontoallaspectsofaproject –oneexamplecomparedtheenergyrequiredtomaintain100lxat4,000Kgiving 67m-EDI(melanopicequivalentdaylight illuminance)butwitha3,000Ksourcethe 100lxgaveonly41m-EDI.Toraisethelatterto67m-EDI,theilluminancemustbe increasedto167lxrequiring ∼65%more energy.

Lambroscitedtwoexamplestoillustrate thepotentialdangersofrelyingonAIgeneratedlightingdesignratherthanusing alightingdesigner,thecomparisonswere striking.Hismostimportantconclusion was‘avoidstupidity’!

CongratulationsgotheLocalOrganizingCommitteeundertheleadershipof ZouhourAraoudandKamelCharradafor arrangingsuchastimulatingandinformativesymposiumwithawarmandwelcomingatmosphere.Thismeetingfullykeptthe traditionofthelightingindustryasafriendly andsupportivecommunity.

Thisreportcoversonlyaselectionofthe papersandposterspresentedduringthe symposium,thefullprogramcanbedownloadedfromtheconferencewebsite: https: //ls2025monastir.com/program-schedule/ Abstractsandpapersfromtheconference willbeavailableviaIEEEXplore.

GeorgesZissisclosedthemeetingand confirmedthenextconferenceinthisseries willbeheldinAthensinearlyDecember, 2026,andhostedbyProfessorLambros Doulos.

SupplementalAmbientLighting InterventiontoImproveSleepin

Parkinson’sDisease:APilotTrial

AndreaS.YooMD1,AdinaWiseMD1,RobertoA.OrtegaMS1,2 , DeborahRaymondMS1,BarbaraPlitnickRN3,JenniferBrons MS3,JudyLiangBS1,SusanB.BressmanMD1,MengxiYang, MPH1,DavidPedler,BA3 , ∗MarianaG.FigueiroPhD3 , ∗Rachel Saunders-PullmanMD,MPH,MS1

Affiliations

1. DepartmentofNeurology,IcahnSchool ofMedicineatMountSinaiandMount SinaiBethIsrael,10UnionSquareEast, NewYork,NY

2. MedicalScientistTrainingProgram, AlbertEinsteinCollegeofMedicine, Bronx,NY,USA

3. LightandHealthResearchCenter,DepartmentofPopulationHealthScience andPolicy,IcahnSchoolofMedicineat MountSinai,1GustaveL.LevyPlace, NewYork,NY

∗JointSeniorAuthors

CorrespondingAuthor

RachelSaunders-PullmanMD,MPH,MS rachel.saunders-pullman@mountsinai.org IcahnSchoolofMedicineatMountSinai, MountSinaiBethIsrael,10UnionSquare East,Suite5JNewYork,NY10003,USA

Keywords: Actigraphy,circadiansystem, circadian-effectivelightexposures,light therapy,mood,Parkinson’sdisease,sleep quality

Importance: SleepdisturbancesinParkinson’sdisease(PD)arecommonandoften adverselyaffectqualityoflife.Lighttherapyhasbenefitedsleepqualityandmood outcomesinvariouspopulationsbutresultstodatewithconventionallighttherapy boxesinPDpatientshavebeenmixed. Wehypothesizedthatapassivelighting intervention,appliedinthemorningand designedtomaximallyaffectthecircadian system,wouldimprovemeasuresofsleep andmoodinPDpatients.

Methods: Inthissingle-arm,within-subjects interventionstudy,baselineobjectivesleep (actigraphy),subjectivesleepquality(questionnaires),andsubjectivemood(questionnaires)datawerecollectedfor1week. Lightingwasthenadministeredtoparticipantsviatable/floorlampsinstalled inthehomeorviapersonallighttherapy glassesfor2hoursinthemorning,7days perweek,overthefollowing4-weekperiod.Post-interventiondataforthesame outcomeswerecollectedduringthefinal weekoftheinterventionperiod.

Results: Among20participants(12women, 8men;mean[SD]age72.1[9.5]years, diseaseduration9.0[5.2]years),duration increasedsignificantlyby28.5min(p = 0 029)andobjectivesleeptimeincreased significantlyby19.9min(p =0 026).

Conclusion: Passiveandeasilyadministeredlightinginterventionsforimproving sleepinPDpatientsholdpromiseasa treatmentformitigatingsymptomsandimprovingqualityoflifeinPD.

Introduction

Parkinson’sdisease(PD)isclassicallydefinedbythepresenceofhallmarkmotor symptoms,butsleepdisturbanceshave alsoemergedasmajornon-motorfactors inthecourseofthedisease [1].REMsleep behaviordisorder,insomnia,fragmented sleep,anddaytimesleepiness [2] occurin up60%ofpeoplewithPD [1],adversely impactingtheirqualityoflifeandlikelyaffectingmotorsymptoms,mood,fatigue, andcognition [3].Researchsuggeststhat circadianrhythmsdisruptionisassociated withsleepdisturbancesandprimarysymptomexpressioninPD [4] andmayalsobe closelyrelatedtotheetiologyofthedisease.

Apreliminaryclinicalinterventionstudyby Videnovicetal.employingtherapeuticlight boxesconcludedthatbrightlightimproved sleepqualityinPD [5].Thisisconsistent withstudiesshowingimprovementsto sleep—aswellasmoodandbehavior— fromasupplementallightingintervention (SALI)developedbyauthorFigueiroand employedinAlzheimer’sdisease(AD)patients [6].However,lightboxescanpose compliance-relatedproblemsduetotheir highlightoutput(usually10,000lx);participantdiscomfort(e.g.,glare,eyestrain, headaches,photophobia,troublemaintainingastaticviewingpositionduringinterventionsessions);andtheneedforprecise placementtoachieveconsistentviewing distancesandangles.TheSALI,onthe otherhand,canbeeffectivelydeliveredat afarmoreflexiblerangeofdistancesand viewingangleswhileparticipantsgoabout theireverydayactivities.

https://icahn.mssm.edu

Thepresentstudysoughttodetermine whethertheSALIwouldimproveobjective (actigraphy)andsubjective(questionnaires) measuresofsleepandsleepiness(primary outcomes)aswellassubjective(questionnaires)measuresoffatigueandmood (secondaryoutcomes)inPD.Participant compliancewiththeSALIandverification oftheSALI’stechnicalspecificationswere monitoredusingpersonallightmetersworn bytheparticipants.Itwashypothesized thatsleepoutcomemeasureswouldimprovewithinterventioncomparedtobaseline.

Methods

ParticipantSelection

Twenty-fourpatientsmeetingtheU.K. Parkinson’sDiseaseSocietyBrainBank DiagnosticCriteriaclinicaldiagnosisofPD wererecruited(November2021through February2023)fromtheBonnieandTom StraussMovementDisordersCenterat MountSinaiBethIsraelMedicalCenterin NewYork,NY,amongpatientswhowere cross-enrolledintheNIHNINDS/NIAU01NS107016study(registeredas NCT05757414withClinicalTrials.gov),and wasnotlimitedtothosewithsleepproblems.Twenty-fourpatientsconsented toparticipateinthepilotlightingstudy, whichwasapprovedbytheIcahnSchool ofMedicineatMountSinaiInstitutional ReviewBoardandconsentforexperimentationwasobtainedfromtheparticipants.

Intervention

Thelightinginterventioncombinedlight spectrumandleveltodeliverarobust light–darkpatternspecifiedformaximally stimulatingthehumancircadiansystem basedoncalculationsdevelopedforthe mathematicalmodelofcircadianphototransductionproposedbyReaandcolleagues [7,8] andusedinpreviousstudies byFigueiro [6,9].Briefly,circadianstimulus(CS)magnitudesaredeterminedfrom circadian-effectivelight,orsimplycircadianlight(CLA),baseduponthespectral sensitivityofthehumancircadiansystem. Abovethemodeledthreshold(CS =0 1), CLA valuesaretransformedinto CS valuesuntiltheyreachapointofdiminishing return(CS =0 7)wherehigher CLA valueshavenogreatereffect.Theinterventiontargeteda CS valueof 0 3 (the effectivevalueforcircadiansystemactivation),whichhasbeenshowntoimprove sleep,mood,andbehaviorinvariouspopulationssuchasADpatients [10].

Thelightinginterventionwasdeliveredfor 2hourseverymorningovera4-weekperiodviacustom-configuredtableandfloor

lamps(chosenby17participants)athome orportablelighttherapyglasses(chosen by3participants)(Figure 1).Deviceselectionwasbasedonparticipants’preferences.

Thetableandfloorlampswerepositioned toensurealightlevelof400lxreached participants’eyes,whichwasequivalent toa CS> 0.3 atthestudy’scriterion distanceof46cm.Lampswerefittedwith asingleA23LEDbulbemitting3,200lmof 3,000Kwarmwhitelight(GreenCreative, SanBruno,CA,US)andprogrammedto automaticallyturnonattimespreferred bytheparticipant,butnolaterthan9:00 AM.Thelighttherapyglasses(Re-timer, LondsdaleSA,AU)providedgreenlight thatwasverifiedtoprovidea CS> 0 3 at theparticipants’eyes.

StudyDesign

The5-weekstudyincludeda1-weekbaselinedatacollectionperiodfollowedbya 4-weeklightinginterventionperiodthat

concludedwithaseconddatacollection periodonthefourthweek.Objectivemeasuresofsleep(wrist-wornactigraphy)and subjectivemeasuresofsleep,fatigue,and mood(questionnaires)werecollectedat baselineandonthestudy’sfinalweekto permitpre-andpost-interventioncomparisons.Thequestionnaireswerefiledbythe participantsthemselvesand/oradministeredbycaregivers.

Actigraphs(PhilipsRespironicsActiwatchL,Murraysville,PA,US; Figure 2A)were wornontheparticipants’non-dominant wristwhileawakeandasleepduringeach datacollectionperiod.Theactigraphy measuresincludedsleepduration,onset latency,wakeaftersleeponset,sleeptime, sleepefficiency,naptimeduringtheday(a measureofdaytimesleepiness),sleepstart time,andsleependtime.

Subjectivesleepwasassessedviathe Parkinson’sDiseaseSleepScale2(PDSS2)andEpworthSleepinessScale(ESS)

Thelightinginterventiondevicesemployedinthestudy: A,tableandfloorlampsusedinthe lightingintervention; B,lighttherapyglassesusedinthelightingintervention.

Datacollectiondevicesemployedinthestudy: A,wrist-wornactigraph; B,Daysimeterwornasa pendant.TheDaysimetermeasures4.5cm(l)×3.7cm(w)×1.6cm(h).Actigraphicmonitoringhighly correlateswithpolysomnographyandsleeplogs.Datacollectedfromthependant-worndeviceclosely correspondtoDaysimetermodelswornateyelevel.

questionnaires,andfatiguewasassessed viatheFunctionalAssessmentofChronic IllnessTherapy–FatigueScale(FACITF)questionnaire.Themoodoutcomes ofdepression,anxiety,andapathywere assessedusingtheHamiltonDepression RatingScale(HDRS),HamiltonAnxiety RatingScale(HAM-A),andApathyScale (AS)questionnaires,respectively(Table 1).

Personallightmeters(Daysimeters)were wornaspendantsbytheparticipantsto continuouslyrecordpersonallightexposuredata(Figure 2B),therebyverifying compliance.Calibratedtothespectralsensitivityofthehumancircadiansystem,the recordedDaysimetervalueswereconvertedintoilluminance(lux), CLA,andCS levels(seeIntervention).

Table1: Thequestionnairesemployedinthisstudy.

Table2: Demographicsandcharacteristicsofstudyparticipantsandactigraphyoutcomes. Demographicsandcharacteristicsof20participantswhoperformedlightingandcompletedactigraphy. RBD,REMsleepbehaviordisorderwaspresentin13individuals.TheseindividualsendorsedRBD behaviorsonquestion1ontheMayoSleepQuestionnaire,althoughpolysomnographywasnotdone. Abbreviations:GBA,GBAgeneencodingforglucocerebrosidase;H&Y,HoehnandYahrScale;LRRK2, Leucine-richrepeatkinase2gene;MOCA,MontrealCognitiveAssessment;RBD,REMsleepbehavior disorder.

StatisticalAnalysis

Theactigraphicsleepmeasuresandtwo ofthesleepquestionnaires(i.e.,PDSS-2, ESS)servedasprimaryoutcomes.The fatigueandmoodassessments(FACIT–F, HDRS,HAM-A,AS)servedassecondary outcomes.Pre-andpost-interventionoutcomemeasureswerecomparedusing one-tailedpairedt-testsfornormallydistributeddataorpairedsampleWilcoxon signedranktestfornon-parametricdata. Wehypothesizedanincreaseinmeanfor actigraphicmeasures,ashasbeenseen inotherstudies [5,6,9,11].StatisticalanalyseswereconductedusingStata17statisticalsoftware(StataCorp,CollegeStation,TX,US)andopen-sourcestatistical programminglanguageRandintegrated developmentenvironmentRStudio(The RFoundationforStatisticalComputing, Vienna,Austria).Comparisonquestionnairescoresweredeterminedforparticipantswhocompletedboththepre-and post-interventionquestionnaires.Data from4participantswereexcludeddueto non-compliance(i.e.,incorrectuseofthe lightingdevicesoractigraphs).Thefinal actigraphyanalysisincludeddatafrom20 participants.Thequestionnaireanalyses includeddatafrom18to20participants, withfullquestionnairesexcludedfora participantiftherewasmissingdataina particularquestionnaire.Thethresholdfor statisticalsignificancewas p< 0 05

Results

Thestudyparticipants’demographicdata andhealthcharacteristicsarelistedin Table 2.Post-interventionmeansleep starttimeoccurred20minearlierand meansleepdurationincreasedsignificantly (Wilcoxonrank p =0 029)by28.5min comparedtobaseline(Figure 3A).Postinterventionmeansleeptimeincreased significantly(p =0 026)by19.9min (Figure 3B).Theseremainedsignificant insensitivityanalysesexcludingthoseusinglightgoggles.Thedifferencesinthe remainingactigraphysleepoutcomeswere notstatisticallysignificant(Table 2).

Despiteoverallgoodobjectivesleepefficiencythroughoutthestudy(Table 2), thequestionnairedatarevealedsubstantiallyimpairedsubjectivesleepquality atbaseline(PDSS-2)thatmarginallyimprovedpost-intervention,althoughthedifferencedidnotreachstatisticalsignificance (Table 3).Post-interventionimprovements werealsonotedfordepression(HDRS) andanxiety(HAM-A),butagainaswith theremainingquestionnaireoutcomes,the differencescomparedtobaselinedidnot reachstatisticalsignificance.Themean

scoresthroughoutthestudyforsubjective sleepiness(ESS)andfatigue(FACIT-F)were withinnormalrange.Overall,meandepressionscores(HDRS)wereintherangefor milddepression.

Discussion

ThispilotstudydemonstratedthattheSALI ledtosignificantlyincreasedsleepduration (p =0.029)andsleeptime(p =0.026) asmeasuredbyactigraphy.Improvements ofsubjectivemeasuresofsleepquality, fatigue,depressionandanxietywerealso observed,butnotstatisticallysignificant. Thislackofsignificancemaybeduetothe smallsamplesizeofthepresentstudyor theshortdurationoftheintervention(e.g., 4weeks).Figueiroetal.showedthatthe SALI’sbenefitsofareobservedandincreasedwithalongerexposuretime [6,9] TheseresultsaugmentthosefromarandomizedclinicaltrialperformedbyVidenovicetal. [5] among31PDparticipants withexcessivedaytimesleepiness(ESS scores≥12)whowererandomizedtoeither brightlightoradimredlightfor14days. Theirpilotstudyshowedthata14-day courseofbrightlighttherapy(compared toadimredlightplacebointervention)sig-

nificantlyreduceddaytimesleepinessand improvedseveralotherself-reportedsleep metrics(ie.,sleepfragmentation,sleep quality,andeaseoffallingasleep).

Lighttherapyhasthebenefitofbeinga minimallyinvasive,non-pharmacologicinterventionthatcanimprovesleepinthose withneurologicaldisorders,butlackof carefuldeliveryandcontrolofthelighting interventionmayresultinhighlyvariable outcomes.Infact,whileonemeta-analysis concludedthatbrightlightsignificantly improveddepressionandinsomniasymptoms [17] inPD,anothermeta-analysis concludedthatbrightlightdidnothave asignificantimpactondepressionand sleepdisordersinPD [18].Theauthorsattributedthelackofsignificancetoprotocol variability,includingtiminganddosesof thelightingintervention [18].Whilestudies inADhavedemonstratedincreasedsleep efficiencyandreduceddepressionandagitationafter4weeksoftheSALI [9],few studieshavelookedattheeffectsoflightinginterventiontoimprovesleepandmood inPD.Currentapproachestolighttherapy forreducingsleepdisturbances,including thoseusedinstudieswithPDpatients,do notintegratelightingtherapyintoaprac-

Figure3: Changeinsleepparametersasmeasuredviaactigraphyfor20participants. A) Meansleeptime wassignificantlygreaterpost-interventioncomparedtobaseline.TheerrorbarsrepresentSEM.

B) Participants’meansleeptimewassignificantlygreaterpost-interventioncomparedtobaseline.

Table3: Resultsforbaseline(i.e.,pre-intervention)andpost-interventionquestionnaires.Abbreviations:AS, ApathyScale;ESS,EpworthSleepinessScale;FACIT-F,FunctionalAssessmentofChronicIllnessTherapyFatigueScale;HAM-A,HamiltonAnxietyRatingScale;HDRS;HamiltonDepressionRatingScale;PDSS-2; Parkinson’sDiseaseSleepScale2.

ticaldeliverysystem,thuscompromising therapeuticvalue.

Thispilotstudyisthefirststudytodemonstratethefeasibilityofadministeringan in-homeSALItoparticipantswithPDusing apassiveinterventionthatfacilitatescompliance.Unlikepreviouspublishedstudies, lightexposuresinthisstudywereassessed andconfirmedusingapersonallightmeasurementdevicethatwascalibratedtothe spectralsensitivityofthecircadiansystem. Ourchoiceofbrightmorninglightdeliveredfromstandinglampsorlighttherapy glassesdiffersfromapproachesemployed inotherstudies,suchastherecentENLITEPDstudy(ClinicalTrials.govIdentifier NCT04291014),whichrequiredparticipantstositclosetoalightboxandlookat thedeviceatdifferenttimesthroughoutthe day.

HereweshowedthattheSALIindeedincreasedparticipants’dailylightexposures, asevidencedbytheincreaseincircadianeffectivelightwiththeintervention.Wealso showedthattheSALIwaswelltolerated withtheaccessibilityofanin-homeinstallationoroptionforportablelighttherapy glasses.Inthissmallgroupof20participants,objectivesleepmeasuresimproved, despitestartingwithacohortwithoverall goodsleepefficiency(85%).

Further,insensitivityanalysesevaluating whetheraneffectwaspresentinearly andlatePD,meanchangeinsleeptimein early-stagePD(definedasHoehnandYahr 1or2, n =16)improvedwithSALI(mean 24.4min, p =0 036);howeverthegroup withadvancedPD,(definedasHoehnand Yahr3or4, n =4),didnot(p =0 178).

AnotherlimitationwastheSALI’s4-week duration,whichmayhavebeeninsufficient forimprovingbehavioroutcomes.Further, alloftheparticipantswereofAshkenazi Jewishheritageowingtotheparentgrant’s focusongenotypesthatareenrichedin thiscohort.Asthegainsobservedthrough applicationoftheSALIandADpatients couldpossiblybenotasreadilygeneralizabletootherpopulations,follow-upstudies currentlyinplacewillincludealargersampleofparticipantsnotlimitedtoAshkenazi Jewishbackgroundandwillbeconducted over8weeks.Thispilotstudydidnotincludeaplacebocontrolarm,althougheverysubjectservedastheirowncontrol, andthusallparticipantsreceivedinterventionaltherapy.Wecannotexcludethat participantsdidnothaveaplaceboeffect.

Futurestudieswillassesseffectsofthe SALIvs.placebocontrolinacross-over studydesign.Thestudy’snotablestrength,

ontheotherhand,liesinitsdemonstration thatdeliveringacircadian-effectiveSALIto PDpatientscanimprovesleepmeasures andmoodsymptomswhilebeingbothwell acceptedandfeasible. ■

Funding

ThisworkwassupportedbyNationalInstituteofNeurologicalDisordersandStroke /NationalInstituteonAging(grantU01NS107016;RSP,MGF),theEmpireClinicalResearchInvestigatorProgram(AW, RSP),theEdmondJ.SafraFellowshipin MovementDisordersbytheEdmondJ. SafraFoundationandMichaelJ.FoxFoundation(AY,RSP),andtheNationalInstituteonAging(grantsR01AG034157and R01AG062288;MGF).

Disclosurestatement

Allauthorsreportnodisclosuresrelevantto themanuscript.

Acknowledgements

Wearegratefultothestudyparticipants whograciouslygavetheirtimeandenergy toparticipateinthisstudy.

References

[1] BaroneP.,AntoniniA.,ColosimoC.,etal.ThePRIAMOstudy:Amulticenterassessmentofnonmotor symptomsandtheirimpactonqualityoflifeinParkinson’sdisease.Mov.Disord.24(2009)1641-1649, https://doi.org/10.1002/mds.22643

[2] ChahineL.M.,AmaraA.W.,VidenovicA.Asystematicreviewoftheliteratureondisordersof sleepandwakefulnessinParkinson’sdiseasefrom 2005to2015.SleepMed.Rev.35(2017)33-50, https://doi.org/10.1016/j.smrv.2016.08.001

[3] SchützL.,Sixel-DöringF.,HermannW.ManagementofsleepdisturbancesinParkinson’sdisease.J.ParkinsonsDis.12(2022)2029-2058, https://doi.org/10.3233/JPD-212749

[4] BreenD.P.,VuonoR.,NawarathnaU.,etal.Sleep andcircadianrhythmregulationinearlyParkinson disease.JAMANeurol.71(2014)589-595, https: //doi.org/10.1001/jamaneurol.2014.65

[5] VidenovicA.,KlermanE.B.,WangW.,etal.Timed lighttherapyforsleepanddaytimesleepinessassociatedwithParkinsondisease:Arandomized clinicaltrial.JAMANeurol.74(2017)411-418, https://doi.org/10.1001/jamaneurol.2016.5192

[6] FigueiroM.G.,PlitnickB.,RoohanC.,etal.Effects ofatailoredlightinginterventiononsleepquality, rest–activity,mood,andbehaviorinolderadults withAlzheimer’sdiseaseandrelateddementias: Arandomizedclinicaltrial.J.Clin.SleepMed.15 (2019)1757-1767, https://doi.org/10.5664/jcsm.807 8

[7] ReaM.S.,NagareR.,FigueiroM.G.Modelingcircadianphototransduction:Retinalneurophysiology andneuroanatomy.Front.Neurosci.14(2021) 10.3389/fnins.2020.615305, https://doi.org/10.3389/ fnins.2020.615305

[8] ReaM.S.,NagareR.,FigueiroM.G.Modeling circadianphototransduction:Quantitativepredictionsofpsychophysicaldata.Front.Neurosci. 15(2021)10.3389/fnins.2021.615322, https: //doi.org/10.3389/fnins.2021.615322

[9] FigueiroM.G.,PlitnickB.A.,LokA.,etal.Tailored lightinginterventionimprovesmeasuresofsleep, depression,andagitationinpersonswithAlzheimer’s diseaseandrelateddementialivinginlong-term carefacilities.ClinIntervAging9(2014)1527-1537, https://doi.org/10.2147/CIA.S68557

[10] FigueiroM.G.Light,sleepandcircadianrhythms inolderadultswithAlzheimer’sdiseaseandrelated dementias.Neurodegener.Dis.Manag.7(2017) 119-145, https://doi.org/10.2217/nmt-2016-0060

[11] StarksteinS.E.,MaybergH.S.,PreziosiT.J.,etal. Reliability,validity,andclinicalcorrelatesofapathy inParkinson’sdisease.J.NeuropsychiatryClin. Neurosci.4(1992)134-139, https://doi.org/10.1176/ jnp.4.2.134

[12] JohnsM.W.Anewmethodformeasuringdaytime sleepiness:theEpworthsleepinessscale.Sleep14 (1991)540-545, https://doi.org/10.1093/sleep/14.6.5 40 [13] MallinsonT.,CellaD.,CashyJ.,HolznerB.Giving meaningtomeasure:Linkingself-reportedfatigue andfunctiontoperformanceofeverydayactivities. J.PainSymptomManage.31(2006)229-241, https://doi.org/10.1016/j.jpainsymman.2005.07.012 [14] MatzaL.S.,MorlockR.,SextonC.,MalleyK., FeltnerD.IdentifyingHAM-Acutoffsformild,moderate,andseveregeneralizedanxietydisorder.Int. J.MethodsPsychiatr.Res.19(2010)223-232, https://doi.org/10.1002/mpr.323

[15] ZimmermanM.,MartinezJ.H.,YoungD.,ChelminskiI.,DalrympleK.Severityclassificationonthe HamiltonDepressionRatingScale.J.Affect.Disord. 150(2013)384-388, https://doi.org/10.1016/j.jad.20 13.04.028

[16] SuzukiK.,MiyamotoT.,MiyamotoM.,etal.EvaluationofcutoffscoresfortheParkinson’sdisease sleepscale-2.ActaNeurol.Scand.131(2015)426430, https://doi.org/10.1111/ane.12347

[17] LinF.,SuY.,WengY.,etal.Theeffectsofbright lighttherapyondepressionandsleepdisturbances inpatientswithParkinson’sdisease:Asystematic reviewandmeta-analysisofrandomizedcontrolled trials.SleepMed.83(2021)280-289, https://doi.org/ 10.1016/j.sleep.2021.03.035

[18] HuangH.-T.,HuangT.-W.,HongC.-T.Brightlight therapyforParkinsondisease:Aliteraturereviewand meta-analysisofrandomizedcontrolledtrials.Biology 10(2021)1205, https://doi.org/10.3390/biology101 11205

DepartmentofNeurology–Mount Sinai

TheDepartmentofNeurologyattheIcahnSchoolofMedicineatMountSinai, includingMountSinaiBethIsrael,providescomprehensivecareforpatientswith neurologicalconditionswhileadvancing researchandeducationinbrainhealth.Its multidisciplinaryteamsaddressabroad spectrumofdisorders,frommovementand neurodegenerativediseasestostrokeand cognitivedisorders.Bycloselylinkingclinicalpracticewithresearch,thedepartment aimstotranslatescientificadvancesinto meaningfulimprovementsinpatientcare.

icahn.mssm.edu/about/departmentsoffices/neurology

MedicalScientistTrainingProgram–AlbertEinsteinCollegeofMedicine TheMedicalScientistTrainingProgram (MSTP)attheAlbertEinsteinCollegeof MedicineoffersanintegratedMD-PhD educationdesignedtotrainthenextgenerationofphysician-scientists.Theprogramemphasizestheconnectionbetween biomedicalresearchandclinicalmedicine, encouragingstudentstoaddresscomplex healthchallengesthroughscientificinquiry. Graduatespursueimpactfulcareersinacademicmedicine,researchinstitutions,and healthcareinnovation.

einsteinmed.edu

LightandHealthResearchCenter–MountSinai

TheLightandHealthResearchCenterat theIcahnSchoolofMedicineatMount Sinaiexploreshowlightinfluenceshuman health,circadianrhythms,andoverallwellbeing.Itsinterdisciplinaryworkbridges populationhealthscience,clinicalresearch, andappliedlightingstrategies.TheCenter’sfindingshelpinformhealthierindoor environmentsinhealthcare,workplaces, andeverydaysettings.

icahn.mssm.edu/research/light-health

InfieldLuminaireCommissioning andReconfiguration

JohannesRüdisser1,JanStark1,ProfessorStefanZudrell-Koch1,2; HigherTechnicalCollegeforEngineeringandAppliedSciences Rankweil,Austria

Today,allormostindustriallighting installationsarecontrolledbybuilding managementsystems,orareatleast connectedtosomekindofdigitalcontrol.Theincreasingdemandforenergy efficiency,costsavingsandoptimized workingenvironmentswilldrivetheindustrytowardsintelligentlycontrolled systems.Thiscanbeconsideredthe state-of-the-art.

Plentyoftechnologieshavebeendevelopedtosupportthisprogress.The mainfocus,formanyyears,hasbeen tomakedigitalinterfacesavailableat noorlowcost.Muchlessfocushas beenonmaintenanceandcommissioningofcomplexsystemsandon technologiestosimplifytheinvolved tasks.Theproject“LumaNet”showcasedasimpleandyethighlyefficient methodtochangetheconfigurationof individualluminaireswithinextended networkswithoutanypriorinformation abouttheinstalledsystem.

Maintenanceorreconfigurationofluminairesin industrialenvironmentsisacostlytask.©HTLR

1 HTLRankweil,Negrellistraße50,6830 Rankweil,Austria

2 stefan.zudrell-koch@htl-rankweil.at

MotivationandBackground

Onceadigitallightingsystemwithanydegreeofcomplexityisinstalledinanewor renovatedbuilding,bothcommissioning andmaintenanceoverthefullservice-life begins,whichconstitutesasubstantial partofthetotalcostofownership.Inmany casestheinvolvedservicepersonnelhave littleknowledgeofthesystemconfigurationandtheaccesstoindividualdevices viatheinstalledcommunicationchannels istedious.Thisprocessofassigningindividualconfigurationdatatoluminairesis timeconsuminganderrorprone.Thelight generatedbyalightsourceisanobvious butnotoftenusedchannelforcommunicatingrelevantdeviceinformationsuch asuniquenetworkIDs,manufacturerdata andcapabilities.Intheproject,LumaNet, aninnovativesolutionhasbeendeveloped andprototypedwhichenablescompatible luminairestobereconfiguredinstantlyin anyfullymountedbuildingsituation.

Theconfigurationorreconfigurationprocessinvolvesfourbasicsteps(Figure 1):

1. Tellallluminairesinsideanarea(room orworkshopsection)toenterconfig mode.Thisisdoneviaabroadcast commandoverthenetworkfromany mobiledeviceorequipment.

2. Useasmartphoneortabletequipped withadedicatedsensorclippedintothe USBconnectorandpointthemobile devicesensortothelightsourcetobe reconfigured.Thelamptowhichthe sensorispointingindicatesitspresence byanykindofvisualeffect(e.g.short flashing).

3. Confirmthattheselectedlampisthe onetobeserviced.

4. Makeanyconfigurationchangesinstantlywithoutanyfurtherinformationof addressesorfixtureIDsorlocations.

Afterreconfigurationiscompleted,thesystemswitchesbackintoitsnormaloperationmodeeithermanuallyorautomatically. Usingthisprocesscommissioningofluminairesisanissueofseconds,saving workloadandcost.Nomanualaccessibility ofthelampdriverisrequired.

Fundamentals

Thestartingpointisasystemcomprisinga setofluminairesequippedwithacompatibledriver.Eachluminaireisconnectedto anykindofbuildingmanagementnetwork andisaddressableviaauniqueID.TheID canbeanIPaddress,MACaddressorany otheraddressuniquelyidentifyingoneluminaire.Thesetofluminairesshallbeone roomordepartmentwithinalargerhall; howeverthenumberofinvolvedluminaires canrangefromonetomanywithnoupper limit.

Upontherequest,theluminairesareset intoa“communicationmode”bymeans ofabroadcastcommand.Inthismode, eachluminairesendsitsownIDviaPWM modulatedlightoutput.Themodulation issuchthatthereisabsolutelynovisible effecttotheuser.TheIDsaredetectedby asmartdigitalsensorwhichispluggedinto amobiledevice.UponreceptionofanID thelampmayindicateitwithavisualeffect, helpingtoestablishacorrectselection. Theindicationisinitiatedbythesensor deviceovertheBMSassoonasavalid addressisreceived.

Thetaskoftheservicepersonistoread, changeorresetanyconfigurationparameterwithinoneparticularluminaireordriver.

Figure1: TheconfigurationprocesswithinLumaNetiseasyandfast.©HTLR/SZK

Figure3: BitdetectionhaserrorwindowsinFSKwithtwomodultationfrequenciesrequiringhighercycle periodesperbit.©HTLR/SZK

Theuser(serviceperson)usesasmartphoneequippedwithadedicatedSWapp aswellasanHWsensor-donglethatsticks intheUSB-Cportofthesmartphone.By pointingthesmartphoneinthedirection oftheluminairetobeserviced,thesensor andappareabletodetecttheparticular IDofthatluminairebyproperlyfilteringthe modulatedsignaloutoftheambientlightin thearea.

ThereceivedIDis,ofcourse,encrypted, anddataintegrityischeckedbymeansof CRCchecksums.OncetheapphasreceivedavalidIDthecorrespondinglamp indicatesitbyvisualeffectsasconfirmation totheuser.Theusercannowconfirmthis lamptobeusedforanysubsequentconfigurationcommand.Whentheconfigurationiscompleted,thesystemautomatically fallsbackintoanewaddressingsequence.

IfareceivedlampIDhasbeenconfirmed, communicationisestablishedandany configurationispossible.Intheprototype system,brightnessandcolortemperature canbechangedineachlightsource.

Thissystemandprocessallowcommunicationwithanylampinacompound withoutanypriorknowledgeofpositions oraddresses,hencegreatlysimplifying maintenanceorcommissioningofbuilding management.

SystemConcept:Defining theModulation

Thefirststepinthedesignprocessisto defineaPWMlightmodulationschemeto meetthefollowingrequirements:

• Fasttransmissionofsmallinformation packages

• Novisibleeffectsinlightoutput

• Highreliabilityindatareception

• Lowprocessingeffort

• EasyimplementationinLEDDriver

Inordertoallowforfasttransmissionof framesthemodulationfrequencyshallbe ashighaspossible.LEDsaslightsources reactalmostinstantlytoanychangein flowofpower,sothePWMfrequenciesare limitedupwardsby:

• CapabilityoftheLEDDriver

• Impactofsecondordereffectslikelimitedcurrentslewratesandsignaldistortioninthelightreceiver

Inpractice,frequenciesinthelowerkHz rangehaveprovedtobeuseful.However, thisimpliessomedegreeofacousticeffects,soitmightbebeneficialtomove intothe20kHz+rangeinfuturedesigns. Inthecurrentprototype,frequenciesbetween3kHzand4kHzhavebeenused, whichareacompromisebetweenspeedof communicationandhardwarelimitations. FrequencyShiftKeyingisusedasamod-

ulationschemetomaintainconstantlight outputatanytime.

Thehumaneyeisextremelysensitiveto smallfluctuationsinlight.Inordertomaintainconstantluminousfluxatanytimeit ismandatorytokeeptheaveragevalue acrossPWM-cyclesexactlyconstanteven whentheunderlyingfrequencychanges. Thismaysoundtrivialbutinpracticethe PMWgenerationhastobemaintainedaccuratelycycle-by-cycleinordertoavoid anyoccurrenceofflicker. Figure 2 shows theconditionsfordifferentmodulation techniques.

Figure2: Withchangesindutycycledueto modulation,averagevaluesmayexperience changesyieldingvisualeffects(top).Withpure andaccurateFSKlightmodulationtheaveragevaluesareconstantatanytime(bottom). ©HTLR/SZK

PWMfrequenciesinthekHzdomaincan easilybeachievedwithstate-of-the-art LEDdriversasMOSFETsareusedpredominantlyforswitchingandthenonlinear effectsarenegligible.

SystemConcept:Defining theModulationScheme

Inordertotransmitandreceiveabinary bitstream,eachdigitalstategetsassigned adifferentfrequency(Figure 3).ThisisobviouslythecaseforFSK.Thereceivercan thendecodethebitstreambyconstantly measuringtheinflowoffrequenciesand thenreconstructthestreamofbits.

Identifyingonesandzerosinthereceived luminousfluxthereforerequiresatiming measurementofeachreceivedPWMcycle.Duetotherequiredfiltersinthelight receiverssomePWMcyclesarenotexactly correlatedtooneofthehigh/lowfrequenciesbecauseofsettlingtimesintherequiredanalogfilters.ThenumberofPWM cyclesusedtotransmitathighorlowfrequencyforonebitmustthereforebelong enoughtoallowforsettlingandforaccuratebitdetection.ThemorePWMcycles areneeded,thelongerittakestotransfer theentiredataframe.

Inadditiontoerrorsintroducedbythe communicationchannel,foreignlampsalso introducenoiseinthedetectedsignalas theyemitmodulatedlightatthesametime. Itisthereforedesirabletohaveamorero-

bustscheme.Thishasbeenachievedby introducinga3-levelmodulationinstead of2levels.Inadditiontoafirstfrequency indicatinglogiclevelhighandasecond frequencyindicatinglogiclevellow,athird “idle”frequencyisusedtoindicatetheterminationofbits.Anybitisusingaminor numberofPWMcyclesandisterminated byanyreceptionoftheterminationfrequency. Figure 4 describesthismethodin moredetail.

SystemConcept:Securing DataIntegrity

Tosecurethatanydecodedreceiveddata streamisholdingvalidinformation,the followingmeasuresareapplied:

A)Thetransmissionprotocolmustbe receivedconsistently.

B)CRCChecksumsaresentwitheach dataframeandarecheckedinthereceiver.

Theprotocolinuseisverysimpleinorder tominimizedataredundancy: Everypackagehasafixedlengthof 32Bits+CRCBits,startingwithastartbit andterminatingwithastopbit.Duetothe limitednumberofbits,aCRCchecksumof length6hasbeenused.However,thiscan beadaptedinfuturedesignsaftermore extensivetestsequences.

Byapplyingtheseconcepts,arobustand securedatatransmissionandreception isachieved.Finally,averysimpleframe encodingconceptisused(Figure 5).A startbitfollowedbya32Bitpayloadisfollowedbya6BitCRCvalue.Theendofone frameismarkedbyidlefrequencyformore thanonebit-length.Thisschemeiseasy todecodeandduetotheerrorchecking providesafastandreliabledetectionofID codese.g.IPaddress.

SystemConcept:Sensing OnlyOneSelected LuminaireWithinaCluster

Asallluminaireswithinacompound–a roomorahall–aretransmitting,simultaneousmeasurementsmustbetakento securethatonlythedatafromtheselected luminaireisreceivedandprocessed.Again, twomeasureshavebeenimplementedto optimizetheselectivitytooneparticularluminaire(Figure 6):

1. Theopticalchannelforthelightsensor hasalargelength/widthratio(a“tunnel”)

Figure4: Bymeansofthreemodulationfrequencies,eachdatabitisterminated,whichenablesshortbit timesandmorerobustdetection.©HTLR/SZK

Frameencodingandframetiming.©HTLR/SZK

Figure6: Tosecurethereceptionofonlyonelightemitteranopticaltunnelinthesensorisprovidedfora narrowfieldofview.©HTLR/SZK

Figure7: BlockschematicofLumaNetLEDDriverbasedonUSB-Cpower.©HTLR/SZK

2. Thetunnelalsoreducesthesignalmagnitudessohighgainsareappliedfor robustsignalreconstruction.

SystemImplementation

Toprovidethefunctionalitydescribedin thepreviousparagraphsasuitabledemonstratorluminairehasbeendeveloped.The requirementsfortheluminairedesignhave beendefinedas:

• Capabilitytomodulatelightoutputfor datatransmissioninadditiontoaccurate linearcurrentdimming

• Luminousefficiency ≥150lm/W

• Tunablewhitebetween2,700Kand 6,500K

• Dimmingcapability10%to100%

• MaxSystemPower40W

• Designasmobileequipmentforeasy transportationanddemonstration

• LinearModeDimmingandPWMMode Dimming

• PowersuppliedoverUSB-CPD

SystemBlockSchematic LEDDriver(Fig.7)

TheUSB-Cblockimplementsthepower deliveryprotocolsuchthata20V/2AinputvoltageisprovidedbytheUSBpower source.TheblockisbasedontheHUSB238 USB-Cmanagementchip [1,2]

ThecentralprocessingunitisanEspressiv ESP32ARMbasedcontrolleralsopro-

vidingWLANconnectivity [3].The20V inputvoltageisboostedupwardsto40V tosupplytheLEDstringsthatareindividuallymanagedbyacurrentcontrollerwhich alsoactsasaswitchifthedatamodulation isactive.Abuckconverterfollowedbya linearregulatorprovidestherequiredinternalpowersupplylevels.The40Vboost converterusesstateoftheartGaNtransistors,andthecurrentandvoltagecontrol loopsareimplementedinsoftwareonthe

Figure8: LEDdriversample(topleft).LEDdriverwithUSB-CconnectormountedunderLEDpanel(top right).LEDdriverandLEDpanel(bottomleft).Luminaireprototype(bottomright).©HTLR/SZK

Figure9: 3Ddesignoftheplug-insensor(topleft).ExplosionviewofsensorwithprocessingPCB(top right).Crosssectionofplug-insensorshowstheopticaltunnelneededfordetection.©HTLR/SZK

Figure10: Blockschematicofsensorelectronics.©HTLR/SZK

ESP32 [4].Inordertomodulatethelight outputfordatatransmissionapreciseand clockaccuratetimingisnecessary.Asthe processorhastomaintaindatatrafficas wellascontrolloopupdatestherealtime capabilityisverylimited.Therefore,the generationofthebitstreammodulationis implementedusinghardwareperipherals withinthecontroller(Figure 8).

Inthisproof-of-conceptprojecteachluminaireimplementsitsownwebserverfor datacommunication.However,itisobviousthatthedatacommunicationand networkprotocolsdonotimpacttheoverall conceptatall.Tousehttpasaprotocol wastheeasiestchoiceintheLumaNet project.

Implementationofthe ReceiverModule

Toreceiveanddecodethemodulatedluminousfluxfromaselectedluminaireatiny USB-Donglelikedesignwaschosen.The requirementshavebeendefinedas:

• PowersuppliedbyUSBinterfacefrom mobiledevice

• Dataexchangewithmobileappvia UARToverUSB

• Smallformfactor

• Plugandplaycapability

• Visualindicationwheneveradecoded deviceIDfromaluminaireisreceived

• Selectivetoasingleluminaireuptodistancesof4–6m

• Discriminationofdaylightandforeign lightsources

Realtimecapabilitycannotbeprovided fromtheappovertheUSBinterface;thereforethesignalreceptionanddecodingare implementedinsidethesensormodule. Onlyapproveddataisthenforwardedto themobiledeviceforanyfurthercommunicationtasks.

Asmentionedbefore,anopticalchannel (Figure 9)isimplementedtoprovidethe requiredselectivityofthesensor.Withappropriatetuningoftheanaloganddigital processingaparticularlightsourcecanbe selectedwithinarangeofupto4m.

AnalogProcessingof DetectorSignal(Fig.10)

Thelightbeamarrivesonthephotodetectorthroughthe“tunnel”.Anarrowview angleensuresthatonlyonelightsourceis seenbythedetector [5].Thephotocurrentofthereceiveristhenmultipliedathigh bandwidthtomakesurethatanyreceived

modulatedradiationispassedthroughasa voltagesignal.Inanextstage,bandlimitingisappliedwhichfiltersoutanydaylight component(DC)aswellasanypotentialhighfrequencynoise.Asecondorder bandwidthfilterwithapassbandgainof 20dBallowingforproperreceptionofinformationalsoatverylowdimminglevelshas beendesigned.Theinitialtargetwastobe abletooperatetheinformationtransferat dimlevelsaslowas10%(Filterdesignwith [6]).

Thefinalstageoftheanalogpartisacomparatorwhichoutputsadigitalsignalthat perfectlyreflectsthebitstreamthatwas modulatedasPWMlightoutputintheLED Driver.

Figure11: Measuredsignalsduringongoing detectionprocess.

Theredcurve(Figure 11)isthedigital signalthatisfedintotheprocessor(RaspberryRp2040, [7]).Thebluecurveisthe modulatedsignalfromthesensor.TheimageshowsthatthePWMlightpulsesare perfectlyreconstructedevenatverylow magnitudesatthesensor.Themeasure-

mentwastakenwith3Luminaireswitha 2mspacingatadistanceofapproximately 4mfromthesensor.

DigitalSignalProcessingof DetectorSignal

Thenextstepintheprocessingchainisto extractanyvaliddatafromthebitstream. Thedigitalinputissampledatafixeddata rateandeachPWMperiodisevaluated accordingtothecriteria:

a)AhighbitisreceivedifPWMperiodis withinafirstwindow.

b)AlowbitisreceivedifPWMperiodis withinasecondwindow.

c)AbitterminationisreceivedifPWM periodiswithinathirdwindow.

d)Cycleisignoredifperioddoesnotfit inanywindow.

Thissamplingandprocessingschemerequiresstrictrealtimeexecutionthatshall beimplementedinaverysmallspaceand lowpowerconsumption.TheRaspberry Rp2040wasselectedastheprocessing platformasitofferscrucialbenefitsfor theserequirements:

• Lowpower<20mA

• Sufficientdatathroughputwith125MHz baseclockfrequencyand32Bitarchitecture

• IntegralUSBinterface

• Dualcoreforparallelprocessingofsignalsanduserinteraction(App)

Figure12: SWarchitectureinsensorwith3-levelprocessingarchitecture.©HTLR/SZK

SmartphonewithLumaNetappandmountedsensor(bottom).Sensorinenclosure(righttop). SensorcontrollerHW(rightmiddle).OpticalTunnelonrearside(rightbottom).©HTLR/SZK

• HardwarePIOperipheralsfor“quasi FPGA”clockaccuratefunctionality

TheSWArchitecture(Figure 12)isstructuredinto3distinctlayersofprocessing:

Thefirstlayerissamplingtheincoming digitalbitstreamwithaclockaccuratetimingbasedonPIOHW.ThePIOsaretiny processingcoresthatbehavesimilarlyto FPGAlogic.Onthisleveleachincoming signalperiodisevaluatedandanydetectionofavalidPWMfrequencyisindicated tothesecondprocessinglayer.Thesecondlayerisusingoneofthe2processor corestoevaluatetheframeprotocolas wellastheCRCchecking.Onceavalid frameisdetected,thecorrespondingIPor MACaddressispropagatedtotheapplicationlevel.Thethirdlayeristheapplication layerwhichmanagesthecommunication withtheservice-apponthemobiledevice whereanyconfigurationorcontrolinformationisforwardedtothecloudandthe BMS.The3rd SWlayerisimplemented inMicropython [8] forveryfastdevelopmentandefficientimplementationofthe interfacetothemobileapp.Onthemobiledeviceaserviceappisinstalledwhich managesthedatatrafficoverUSBtothe sensordongleaswellasthedataflowover WLANtotheBMS.Inthecurrentprototype,onlysomebasicfeaturesareimplementedlikesettingthelightlevelandcolor temperature.

SummaryandConclusions

Inthisprojectanovelmethodforcommissioningorreconfigurationofinstalled luminairesisproposedandaprototype systemhasbeendevelopedandtested. Theconceptfoundationisthatluminaires sendtheirdeviceaddress(MACorunique ID)asPWMmodulatedlightoutput.Usingatinydongle-likesensorwhichplugs intoanysmartphoneandallowstheuser tocommunicatewithaparticularinstalled luminaireforconfigurationorreprogramming.Adedicatedsetoflightfixturesand suitabledrivershavebeendevelopedas wellasthedonglesensor.Theconcept hasbeenproofed,andtheinitialproject requirementscouldbefullymet.Thesystemoffersarangeoffurtherimprovements onceacomprehensivefieldtesthasbeen executed(Figure 13).

Theprojectwasawardedas3rd best youngscientificstudentprojectby“SpecialAwardVorarlberg”.

Manythankstoourprojectsponsor TRIDONICandtoMr.DietmarKlienfor theirexcellentsupport. ■

References

[1] https://www.usb.org/usb-charger-pd

[2] https://www.hynetek.com/uploadfiles/site/219/new s/24322c00-2276-4d74-98db-c74432318210.pdf

[3] https://www.espressif.com/en/products/socs/esp32

[4] https://www.ti.com/lit/ds/symlink/lmg5200.pdf?ts=1 768919955737

[5] https://www.vishay.com/docs/81521/bpw34.pdf

[6] https://tools.analog.com/en/filterwizard/

[7] https://pip-assets.raspberrypi.com/categories/610-r aspberry-pi-pico/documents/RP-008307-DS-1-pic o-datasheet.pdf?disposition=inline

[8] https://micropython.org/

AboutHTLRankweil

HTLRankweilisanAustrianhigher-level technicalinstitutionprovidingadvanced secondaryandpost-secondaryeducation inengineeringandappliedsciences.SituatedintheregionofVorarlberg,theinstitutionfollowsarigorous,practice-oriented educationalmodelthatintegratessolidtheoreticalinstructionwithappliedtechnical training.

TheacademicprofileofHTLRankweilencompassesdisciplinessuchasmechanicalengineering,electricalengineering, automation,andindustrialsystemsengineering.Thecurriculumiscontinuously alignedwithtechnologicalprogressthrough closecooperationwithindustrialpartners, appliedresearchinitiatives,andprojectbasedlearningformats.Thisapproach enablesstudentstodevelopstronganalytical,methodological,andengineering competencies.

HTLRankweilemphasizesinnovation,interdisciplinarythinking,andsustainable technologicaldevelopment.Itsgraduates arewellpreparedforfurtheracademic studiesatuniversitiesanduniversitiesof appliedsciences,aswellasforprofessionalrolesinengineering,research,and industrialdevelopmentinaninternational context.

HTLRankweil

HigherTechnicalCollegeforEngineering andAppliedSciences

Negrellistraße50

6830Rankweil

Austria +43552244260

mailto:office@htl-rankweil.at www.htl-rankweil.at

Authors:JohannesRüdisser,JanStarkandStefanZudrell-Koch(lefttoright).©Authors

ThespecialawardwaspresentedbyDr.BarbaraSchöbi-Fink,RegionalMinisterofEducation,andMichael Tagger,aBoardMemberofthe“SpecialAwardVorarlberg”.©LandVorarlberg/7PRO.TV

Author:JohannesRüdisser isagraduateofHTLRankweil,wherehespecialized inElectronicsandTechnicalComputerScience.Heservedastheteamleaderforthe LumaNetproject,wherehewasresponsibleforhardware,embeddedsoftwareand mechanicaldesign.Johanneshasreceived severalawardsinmusicandmathematics. Lookingahead,JohannesintendstopursueadegreeinElectricalEngineeringinthe comingyears,furtherenhancinghisskills andknowledgeinthisdynamicfield.

Author:JanStark graduatedfromHTL Rankweilspecializinginthefieldofsoftwaredevelopment.IntheLumaNetproject hewasresponsibleformobileappdevelopment.

Author:ProfessorStefanZudrell-Koch servedasthesupervisoroftheLumaNet Project.Hehasextensiveexperiencein lightingresearchanddevelopment,witha focusonthedesignofdriversandcontrol ICs.Aftermanyyearsinseniormanagementroleswithinthepowerelectronics industry,hejoinedHTLRankweilin2018 asaProfessorofControlDesignandHardwareEngineering.Hiscurrentresearch activitiesfocusoninnovationinpowerelectronics,particularlytheapplicationofGaN technology.

HTLRankweil,Negrellistraße50,6830 Rankweil,Austria

stefan.zudrell-koch@htl-rankweil.at

Note:Imagerights©HTLR/SZK–HTL Rankweil,StefanZudrell-Koch;©HTLR–HTLRankweil.

LightingMetricsDemystified: HowPhotometricDataDrives QualityandEfficiency

XavierDenis,HeadofTechnicalSupportandTechnicalMarketing atNichiaEuropeGmbH

WhyLightingMetricsMatter

Highqualitylightingisessentialforourwellbeing,andourabilitytofunctioneffectively. Weneedcomfortable,glare-freeilluminationthatenablesustowork,orthathelps ustorelax.

Howdowedefinequalityinlighting?Traditionalapproacheshavefocusedonmeasurablecriteria,suchasilluminancelevel, colorrendered,andthelimitationofglare, whilemorerecentlytheindustryisshiftingtohuman-centriclighting(HCL)approaches,thatassessthepersonalimpact oflights2.Inpractice,acombinationof HCLthinkingandtraditionalmetricsoften worksbest.

Forlightingdesigners,thesheernumber ofmetricsthatexistcanbeoverwhelming, andthereisnosingledefinitionoflighting qualitythatisacceptedbyall3.Industry bodiesandmanufacturersprovidecomplex combinationsofdata,whichcanbeinconsistentanddifficulttounderstand.

Althoughmoderndesignsoftwarecan handlemuchofthiscomplexity,alighting designermuststillunderstandthekeymetrics,andhowtheycanbeusedtoevaluate lightingquality.Designersneedaccurate datafromlightingmanufacturers,supportedbyLEDchipsuppliers,toenable themtocreateaccuratelightingcalculationsandsimulations.

Inthisarticle,we’llexplainsomeofthe mostimportantcriteriaforlightingdesign andquality,andthechallengesinvolvedin obtainingandusingthisphotometricdata.

TheKeyStandards

Whiletherearemanyalternativesthat couldbeused,thebestapproachisusually toworkfromacombinationofup-to-date metrics,thatmeasuredifferentaspectsof thequalityoflighting.

Wecangroupthesemetricsintothree mainareas:

• Colorquality

• Visualcomfort(includingglare)

• Overalldesign(includingefficiency)

Forcolorquality,thelongstandingmetric ofchoicehasbeenColorRenderingIndex (CRI),whichprovidesameasure,comparedtonaturallight,ofhowaccurately colorsappearwhenilluminatedbythelight sourcebeingassessed.

WhileCRI15,theextendedversionofCRI, iscurrentlythemostcommonlyusedstandard,another,similarmetricisTM-304 , whichwasdevelopedbytheIlluminating EngineeringSociety(IES).AswithCRI15, theTM-30methodevaluatesthedifferencebetweencolorsamples,whichcover awiderangeofhue,illuminatedbythetest lightsourceandareferencesource.

Next,whenweconsidervisualcomfort, themostimportantsinglefactorisglare. UnifiedGlareRating(UGR)isthestandardmetrictoassessit.Asspecifiedinthe standardEN12464-1“Lightingofindoor workplaces”,UGRassessesthevisualimpactofglareuponaperson,consideringall thelightsourcesthatmightcontribute,and anyreflections.Forspaceswithsignificant daylight,anotherusefulmetricisDaylight GlareProbability(DGP).Usingpublished data,theUGRstandardenablesasingle figureofglareleveltobecalculated.Lower numbersarebetter,andEN12464-1spec-

ifiesthatofficesshouldhaveaglarelevelof 19orbelow5

Movingontooveralldesignandefficiency, designersneedtolookatthebrightness ofalight,orluminousflux,whichismeasuredinlumens.Thisenablesadesignerto ensurethatthespacebeingilluminatedis brightenough.Then,theenergyefficiency ofalightsource,orefficacy,inlumenper watt,isanessentialdatapointinenabling sustainabledesignsthatmeetenvironmentalstandards.

Beyondthiscoremetric,therearemultiple othercriteriathatdesignersshouldconsider,dependingontheirspecificproject. Thismightincludemeetingrelevantbuildingregulationsandlegislationrelatedto workingwithcomputerscreens,aswellas rulesaroundprovidingemergencylighting.

ChallengesFacedby LuminaireManufacturers

Luminairemanufacturersneedtoprovide alltheinformationrequiredbylightingdesigners,theircustomers,tocreateefficient andeffectivesystems.Buttheirbiggest challengecanbeingettingenoughdata fromLEDmanufacturersandothercomponentsuppliers.Nichiaisproudtohave agoodtrackrecordinprovidingdetailed specificationdocuments.

Additionally,thereisoftenalackofconsistentmetricsfromdifferentluminairemanufacturers,solike-for-likecomparisonsof lightingproductsaredifficult.Manufacturersalsosometimeslackdatatoshowhow theperformanceofalightingproductwill changeoveritslifetime,althoughthisisaddressedbystandardssuchasTM-216

2TheLightingHandbook,Zumtobel, https://www.zu mtobel.com/PDB/teaser/EN/lichthandbuch.pdf

3BuildingandEnvironment, https://www.sciencedirec t.com/science/article/pii/S0360132318302397

4IES, https://ies.org/fires/using-tm-30-to-improve-y our-lighting-design/

5https://www.performanceinlighting.com/gb/en/en-1 2464-1

6LEDLightExpert, https://www.ledlightexpert.com/t m-21-light-standard_ep1

LEDchipmanufacturerssuchasNichia providerawdataforindividualcomponents,suchastheluminousflux(lumens), luminousintensitydistributionandLED efficacy,underspecificandcontrolledconditions.

However,integratingachipintoaluminaire generatesperformancelosses.Thoseincludeefficiencylosses,mainlyduetoheat, fromelectronicparts,andlosses,dueto coupling,fromopticalcomponents.Anotherfactorisvariationinthedistribution ofluminousintensitybecauseoftheluminaire’sopticaldesign.Theselossesand variationsmeanthattheoverallefficacyof aluminaireislowerthantheefficacyofthe LEDchipalone.

PossibleSolutionsfor BetterData

Toovercometheseissues,andtoprovide thephotometricperformancedataneeded bylightingdesigners,luminairemanufacturersneedtotakeseveralkeysteps.Firstly, theymustprovideend-to-endperformance datafortheentireluminaire,notjustthe LEDchip.Thisshouldincludeefficacyand informationonphotometricmetrics,aswell asdataonhowlumenvalueswilldecrease duetoaging.

Secondly,luminairemanufacturersshould useindependent,standardizedtesting suchastheLM-79measurementstandard publishedbyIES7

Thisenablesthemtomeasuretheimpact ofoptics,drivers,andothercomponents onphotometricperformance,andtoprovidedatathatcanbeusedincomparisons withothervendors’products.

Finally,theyneedtoprovideallthesedata inaconvenientformforuseinlightinganalysissoftware.Typically,thismeanscreating IESorEULUMDATfilesthataccuratelyrepresentthefinalperformancemetrics.All thisinformationshouldbeputtogetherwith referencetothestandardsandguidelines providedbyindustrybodies,suchasthe SLLCodeforLighting,publishedbyCIBSE intheUK8

Conclusion:DrivenbyData

Qualityinlightingmaybeseenasasubjectiveissue,butwehaveshownhow quantified,objectiveinformationcanenablelightingdesignerstocomparedifferent luminaires,andtooptimizetheirlighting systems.

LEDmanufacturersandluminairemanufacturershavearesponsibilitytowork togethertoprovideconsistent,accurate data,sowecanallbenefitfromefficient, high-qualitylighting. ■

LEARNMORE...

NichiaApplicationNoteonColorRendering EvaluationofLEDsforGeneralLighting

led-ld.nichia.co.jp/en

XavierDenis,NichiaEuropeGmbH HeadofTechnicalSupportandTechnical Marketing

7TUVSUD, https://www.tuvsud.com/en-us/industri es/consumer-products-and-retail/lighting/testing/lm79

8CIBSE(theCharteredInstitutionofBuildingServices Engineers), https://www.cibse.org/knowledge-research/ knowledge-portal/sll-code-for-lighting-2022/

Nichia’sH6LEDisanexamplethatdeliversbothhigherefficacyandhighercolorrenderingthantraditionalLEDswhilemaintaininganefficacybetterthanRa≥80 LEDs.

FromLightingControltoThermal Intelligence

SaaraGuastella,Casambi;KevinJohnstone,DanlersLimited;and BartdeJong,Calumino

Theevolutionoflightingcontrolsystemsoverthepastdecadehasfundamentallyreshapedhowbuildings aredesigned,operated,andexperienced.Whatbeganaswirelessdimmingandscene-settinghasexpanded intoabroaderplatformfordata-driven buildingintelligence.ThelatestintegrationbetweenDanlersLtd.,Casambi Technologies,andCaluminomarksa significantmilestoneinthistransformation:Thedeliveryofacommercially available,privacy-safethermalsensingsolutionembeddeddirectlyintothe Casambiwirelesslightingecosystem.

Realoccupancydata,zerocameras,seamless Casambiintegration.

Privacy-safehumandetectionandcounting,built intoDanlerscontrollers.

FollowingtheinitialpartnershipannouncementbetweenCasambiandCaluminoin 2024,thevisionofbringingthermalsensing tomass-marketsmartbuildingapplications hasnowbeenrealizedinaready-to-deploy solution.ThroughDanlers’plug&play Casambi-compatiblesensorswith“CaluminoInside,”lightingprofessionalscan nowaccessadvancedthermalintelligence, occupancydetection,andpeoplecounting withinaunifiedlightingcontrolplatform.

Thisarticleexploreshowthecollaboration movedfromconcepttodeployment,the technicalcapabilitiesoftheintegratedsolution,andwhatitmeansforthefutureof smartlightingandbuildingautomation.

TheGrowingRoleof SensinginLightingSystems

Lightinginfrastructurehasbecomeoneof themostattractiveplatformsforsensing technologies.Luminairesarealreadydistributedthroughoutbuildings,connected topower,andpositionedoptimallyforobservingspaceusage.Asaresult,lighting controlnetworksareincreasinglyusedas thebackboneforoccupancydetection,energyoptimization,anddatacollection.

Traditionalsensingmethods,suchasPIR motionsensorsorcamera-basedsystems, haveclearlimitations.PIRsensorsstrugglewithaccuracyincomplexspacesand oftenfailtodetectstationaryoccupants. Camera-basedsolutionsraiseprivacyconcerns,regulatorychallenges,andacceptanceissues,particularlyinworkplaces, healthcareenvironments,andhospitality settings.

tion,andgreatersignal-processingcomplexity.Indenseorreflectiveenvironments, radarmayalsosufferfrominterference, calibrationchallenges,orover-detection, whichcanimpactreliabilityandeaseofdeployment.

Thermalsensingoffersanalternativeapproach.Bydetectingheatsignaturesrather thanvisualimages,low-resolutionthermal sensorscanidentifyhumanpresenceand movementwithoutcapturingpersonally identifiableinformation.Thismakesthermal sensingparticularlyattractiveforapplicationswhereprivacy,compliance,andtrust arecritical.Andasthermalsensingworks basedonlineofsight,itiseasytocommission.

Calumino’smissionhasbeentodemocratizethisformofsensingbymakingit affordable,scalable,andeasytointegrate intoexistingbuildingsystems.ThepartnershipwithCasambiandDanlershasbeen instrumentalinturningthatambitionintoa deployablesolution.

FromConceptto Market-ReadyIntegration

InMay2024,Casambipublishedanarticle titled“Caluminobringsthermalsensingto massmarketapplications”,outlininghow Calumino’stechnologycouldbeintegrated intoCasambi’swirelesslightingmeshto unlocknewlevelsofspatialintelligence.At thetime,theannouncementrepresented aforward-lookingvisionratherthanan immediatelyavailableproduct.

Danlers,CasambiandCalumino

DeliveraPrivacy-Safe,Plug&Play SensingSolutionforSmartBuildings

Radar-basedsensinghasemergedasa neweralternative,usingradiowavesto detectmotion,presence,andevenmicromovementssuchasbreathing.Radarcan performwellinlow-lightorobscuredconditionsandoffershighersensitivitythanPIR. However,radarsystemsoftencomewith highercosts,increasedpowerconsump-

Overthepastyear,thatvisionhasbeen transformedintoafullytestedandcommerciallyvalidatedsolutionthroughclose collaborationbetweenthethreecompanies.

Thekeydevelopmentwastheembedding ofCalumino’sintelligentthermalsensor andedgeanalyticsintoDanlers’plug& playCasambi-compatiblesensors.Danlers

broughtitsexpertiseinrobust,installerfriendlyhardwaredesign;Caluminocontributeditssensingtechnologyandanalytics;andCasambiprovidedthewireless meshecosystem,commissioningtools, andintegrationframework.

Theresultisnotaprototypeorbespoke integration,butastandardizedsolution thatcanbeinstalled,commissioned,and operatedusingthesameworkflowsfamiliar toCasambisystemintegrators.

Privacy-FirstThermal SensingwithEdgeAnalytics

AtthecoreofthesolutionisCalumino’s low-resolutionthermalsensor,designed specificallyforprivacy-safeapplications. Unlikecamerasorhigh-resolutionimagingsystems,thesensordoesnotcapture recognizablevisualinformation.Instead, itdetectsthermalpatternsandprocesses themlocallyusingembeddededgeanalytics.

Thisapproachenablesreliablehumandetection,presencemonitoring,andpeople countingwithouttransmittingrawimage dataorcompromisingoccupantprivacy. Allanalyticsareperformedonthedevice, reducingdatatrafficandminimizingcybersecurityrisks.Forbuildingoperators,this translatesintoactionableinsightswithout theethical,legal,andoperationalchallengesoftenassociatedwithvision-based sensingsystems.Foroccupants,itprovidesreassurancethattheirprivacyisrespected,anincreasinglyimportantfactorin smartbuildingadoption.

NativePeopleCounting WithintheCasambi Ecosystem

Oneofthemostsignificantoutcomesof theintegrationistheintroductionofanativeCasambi-supportedpeoplecounter poweredbyCalumino’ssensingtechnology.Occupancyandcountdatacan nowbeuseddirectlywithintheCasambi ecosystemorsharedwithconnectedsystems.

Thisopensthedoortomultipleusecases:

• Lightingcontrolthatrespondsdynamicallytorealoccupancyratherthansimplemotionevents

• HVACoptimizationbasedonactualpeoplecountsratherthanschedulesorassumptions

• Spaceutilizationanalyticsforfacility managementandoperationalplanning

• Integrationwithbuildingmanagement systemsusingCasambi’sAPI

Bymakingpeoplecountinganative,supportedfeatureratherthanathird-party add-on,Casambistrengthensitsposition asaplatformnotonlyforlightingcontrol, butforbroaderbuildingintelligence.

Multi-ZoneMonitoringwith theNew1+8Functionality

AkeytechnicalinnovationenabledbyCalumino’sthermalsensingisthenew1+8 presenceandabsencefunctionality.With thiscapability,asinglesensorcanmonitor andindependentlyconfigureuptoeight distinctzoneswhilestilltreatingtheoverall areaasoneunifiedspace.

Thisisparticularlyvaluableinenvironments suchasopen-planoffices,hotellobbies, meetingrooms,corridors,orhealthcare facilities,wheremultiplefunctionalzones existwithinasinglephysicalarea.

Fromapracticalstandpoint,the1+8functionalitydeliversseveralbenefits:

• Reducedhardwarerequirementsby coveringmultiplezoneswithonesensor

• Fasterinstallationandcommissioning

• Lowersystemcost

• Simplifiedconfigurationandadjustment throughtheCasambiapp

AllzonesettingsandbehaviorsaremanagedwithinthefamiliarCasambicommissioningenvironment,ensuringconsistency withexistinglightingcontrolworkflows.

Plug&PlayDeployment ThroughDanlersControllers

Easeofinstallationhasbeenadefining principleofCasambi’ssuccess,andthe Danlersintegrationmaintainsthisphilosophy.ThenewDanlerscontrollerswith CaluminoInsidearedesignedastrueplug &playdevices.

Systemintegratorscaninstallasinglecontroller,commissionitusingtheCasambi app,andimmediatelygainaccessto:

• Wirelesslightingcontrol

• Thermalpresencedetection

• Peoplecounting

• Occupancy-basedlogicandautomation

Thereisnoneedforseparatesensingnet-

works,additionalgateways,orcomplex systemintegrationsteps.EverythingoperateswithintheCasambimesh,benefiting fromitsscalability,reliability,anddevice interoperability.

Thisapproachsignificantlylowersthebarriertoadoptingadvancedsensingcapabilities,makingthemaccessiblenotonly tolarge-scaleprojectsbutalsotosmaller installationswherecomplexityandcost wouldotherwisebeprohibitive.

UnlockingNewApplications AcrossBuildingTypes

Thecombinedcapabilitiesoflightingcontrolandthermalsensingenableawide rangeofapplicationsacrossdifferentsectors.

In officeenvironments,accurateoccupancydatasupportsenergy-efficientlightingandHVACoperation,improvesspace utilizationanalysis,andenhancesemployee comfort.

In hospitality,thermalsensingenables adaptivelightingscenes,optimizedclimate control,andbetterunderstandingofguest movementpatterns,allwithoutcompromisingprivacy.

In healthcare,theprivacy-safenatureof thermalsensingisparticularlyimportant, allowingmonitoringofspaceusageand presencewithoutintroducingcamerasinto sensitiveareas.

In educationandpublicbuildings,the solutionsupportsflexiblespacemanagement,energysavings,andcompliancewith dataprotectionrequirements.

Acrossalltheseenvironments,theintegrationdemonstrateshowlightinginfrastructurecanserveasafoundationforsmarter, moreresponsivebuildings.

EcosystemCollaborationas aCatalystforInnovation

Thesuccessofthisintegrationhighlights theimportanceofecosystemcollaboration inthesmartlightingindustry.Casambi’s open,partner-drivenecosystemallows specializedtechnologieslikeCalumino’s thermalsensingtobeembeddedinto productsfromhardwareexpertssuchas Danlers,creatingsolutionsthataregreater thanthesumoftheirparts.

KevinJohnstone,COOatDanlersLtd., emphasizesthepracticalimpactofthis approach:

“OurcollaborationwithCaluminoandCasambirepresents amajorleapforwardforintelligentbuildingcontrol.With Calumino’sthermalintelligence integratedintoourplug&play Casambicontrollers,wecan deliversmarter,moreefficient, andprivacy-safesolutionsthat arereadytoinstalloutofthe box.”

KEVINJOHNSTONE

FromCalumino’sperspective,theintegrationfulfillsitsoriginalmission.Bartde Jong,CommercialDirectornotes:

“AtCaluminowesetoutto bringthermalsensinginto themassmarket—andthe partnershipwithCasambiand Danlerswasacatalystforthat mission.Today,withouranalyticsembeddedinaproven lighting-controlecosystem,we aredeliveringtheactionable datathatbuildings,facilities andpeopleneed.”

BARTDEJONG

Casambiseestheintegrationasanatural extensionofitsecosystemstrategy.ViktorOlsson,DirectorofEcosystemSales EMEA,adds:

“Casambi’secosystemthrives onpartnerswhoinnovateat theintersectionofsensingand control.Wearedelightedto seeDanlersandCalumino deliverthepromiseweannouncedin2024—enabling smarter,moreresponsive lightingandbuildingsystems.”

VIKTOROLSSON

AvailabilityandOutlook

TheDanlerssensorswithCaluminoInside areavailablenowthroughDanlers’distributionnetworkandcanbeseamlessly integratedintoanyCasambinetworkusing theCasambiapp.

Lookingahead,theintegrationsignalsa broadershiftinthelightingindustry.As sensing,analytics,andcontrolconverge, lightingsystemsareevolvingintoplatforms foroperationalintelligence,sustainability, anduser-centricdesign.Privacy-safetechnologiessuchasthermalsensingarelikely toplayacentralroleinensuringthatthis evolutionalignswithsocietalexpectations andregulatoryframeworks.

Forlightingprofessionals,systemintegrators,andbuildingowners,thecollaboration betweenDanlers,Casambi,andCalumino demonstrateshowinnovationwithinan openecosystemcantranslatequicklyfrom visiontomarket-readyreality. ■

Casambi isaBluetoothLowEnergy–basedwirelesslightingcontrolplatform enablingflexible,interoperable,andscalablesmartlightingnetworks.

DanlersLimited developsandmanufactureslightingcontrolsensorsandsolutions forprofessionalandcommerciallighting applications.

Calumino developsthermalsensortechnologyenablinganonymouspeopledetectionandoccupancysensingforsmart buildingsandlightingsystems.

SaaraGuastella

GlobalProductMarketingManager saara.guastella@casambi.com

PREVIEW∗

Mar/Apr2026|LpR114

Light+BuildingShowReport

ThenextissueofLEDprofessionalReview (LpR),March/April2026,willprimarilyfocus onthehighlightsofLight+Building2026in Frankfurt.Thisissuewillspotlightthelatest trends,technologies,andmarketdevelopmentsshapingthelightingindustry.In addition,wewillpresentacuratedselection ofthemostimportantandmostinteresting newproductinnovations.

∗ Subjecttochangewithoutnotice.

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CoverPage: HyparschaleisoneofMagdeburg’smost distinctivearchitecturallandmarksandakeyexampleof postwarmodernisminGermany.LightingDesignby LichtvisionDesignGmbH,Berlin|HongKong|London| Shanghai.ImageCredits:UlrichSchwarz, info@ulrichschwarz.eu.