Delft University of Technology
Behavioral patterns and profiles of electricity consumption in dutch dwellings
Bedir, Merve; Kara, Emre C.
DOI
10.1016/j.enbuild.2017.06.015
Publication date
2017
Document Version
Final published version
Published in
Energy and Buildings
Citation (APA)
Bedir, M., & Kara, E. C. (2017). Behavioral patterns and profiles of electricity consumption in dutch
dwellings. Energy and Buildings, 150, 339-352. https://doi.org/10.1016/j.enbuild.2017.06.015
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ContentslistsavailableatScienceDirect
Energy
and
Buildings
jo u r n al h om ep a g e :w w w . e l s e v i e r . c o m / l o c a t e / e n b u i l d
Behavioral
patterns
and
profiles
of
electricity
consumption
in
dutch
dwellings
Merve
Bedir
a,∗,
Emre
C.
Kara
baDelftUniversityofTechnology,FacultyofArchitecture,DepartmentofArchitecturalEngineering+Technology,DesignInformatics,Julianalaan134,2628
BLDelft,TheNetherlands
bDepartmentofCivilandEnvironmentalEngineering,CarnegieMellonUniversity,5000ForbesAve,Pittsburgh,PA15213,USA
a
r
t
i
c
l
e
i
n
f
o
Articlehistory:
Received20February2017
Receivedinrevisedform12May2017 Accepted10June2017
Availableonline12June2017 Keywords:
Energyefficiency Occupantbehavior
Behavioralpatternsandprofiles Electricityconsumption Dutchhouseholds
a
b
s
t
r
a
c
t
InEUmemberstates,theconsumptionofelectricityperdwellinghasremainedmoreorlessconstant, althoughtheconsumptionoflargeapplianceshasdecreasedconsiderablyinthelast2decades.This stabilizationiscausedbytheincreasedownership,usageandconsumptionlevelsofInformation, Com-municationandEntertainment(ICE)appliances.Thispaperaimstoanalyzeelectricalapplianceuseinthe Dutchhousingstock,andidentifybehavioralpatternsandprofilesofelectricityconsumption.The anal-ysisisconductedbyapplyingdescriptive,correlation,andexploratoryfactoranalysesondatacollected from323dwellingsintwoneighborhoodsintheNetherlands.Ourresultsshowthatbehavioralpatterns couldbefoundbasedonactualoccupantbehavioroflightingandapplianceuse,especiallydepending onhouseholdactivitieslikecooking,(personal)cleaning,etc.Behavioralprofilescouldbedetermined basedonhouseholdanddwellingcharacteristics,i.e.householdsize,income,education,dwellingtype, age,hoursofworkingoutside.The4profilessetupinthisresearchareexplainedas‘family,’‘techie,’ ‘comforty,’and‘conscious.’Theseprofilesshowedstatisticallysignificantlydifferencesintermsoftheir electricityconsumptionlevels.
©2017ElsevierB.V.Allrightsreserved.
1. Introduction
Residential buildings consume 23% of the electricity in the Netherlands[1].ODYSSEE-MUREprojectreportsthat,inEuropean Union(EU)countries,althoughtheconsumptionoflargeappliances hasdecreasedconsiderablybetween2000and2012(Fig.1(left)), increasingownershipanduseofappliancesandlargerhomespush theelectricityconsumptionupbyabout0.4%peryear,per house-hold[2].Household electricityconsumption in theNetherlands hasfolloweda similarpattern totheoneofEU (Fig.1 (center) and(right)).Whiletheefficienciesofwashingmachine,dryer,dish washer,refrigerator,and freezerhaveimmenselyimprovedand theiruseremainedsimilar,thusreducingtheiroverallelectricity consumption;theownership,usagetimeandpowerofcomputer, printer,TV,DVD,and otherpersonal electronicdevices, electric oven, microwave oven, kettle, and similar have gone up, thus increasingtheiroverallelectricityconsumption[3].
These statistics point to the importance of the influence of occupants’ownershipanduseoflightingandappliances,and
sys-∗ Correspondingauthor.
E-mailaddresses:mb@landandcc.com(M.Bedir),ekara@stanford.edu (E.C.Kara).
temsontheelectricityconsumptionindwellings.Severalstudies haveclaimed thathouseholds canachievemore energysavings bychangingoccupantbehavior[4–8].Therefore,itisimportantto analyzetheshareofoccupantbehaviorinenergyconsumptionin detail.Moreresearchontheissueisneeded;however,thereare severalreasonstowhythisisdifficult,someofwhicharethe retro-spectivemethodsofdatacollectionbytheenergycompanies,the assumedusagepatternsofsystemsandappliancesinmost calcu-lationtools,theuncertaintiesincollectingandanalyzingdata,the issuesofenergyperformancegap[9].
Inexistingresearch,behavioralfactorsrelatedtoheatingenergy consumptionhavebeenidentified,aswellasthehouseholdand dwellingcharacteristicsthatarerelatedtothesebehavioralfactors [10–12].Thestudiespointtothepotentialofenergyconsumption reduction,ifenergyefficiencypoliciesarearticulatedaccordingto differenthouseholdprofiles[10,13].Theabilitytomakeaccurate predictionsoftheelectricityusageofhouseholdsisanimportant issuenotonlyforpolicybutalsoforenergycompanies,andwill becomeevenmoreimportantwiththeemergenceofsmart elec-tricitygrids[9].
IntheNetherlands,variousstudieshavebeenconductedwith theaimofidentifyingbehavioralpatternsrelatedtohigherlevels ofheatingenergyconsumptionand/ortoenergy-savingattitudes, howeverthereisnosuchstudyforelectricityconsumption behav-http://dx.doi.org/10.1016/j.enbuild.2017.06.015
Fig1.AverageelectricityconsumptionperdwellinginEU(left),ElectricityconsumptionoflargeelectricappliancesandTV(middle),Ownershipofappliancesinthe Netherlands(right).
ior.Ourworkcontributestotheliteraturebyproviding detailed informationaboutelectricityconsumptionbehavior,andby deter-miningthepatternsandprofilesofusers.Existingresearchsuggests that occupant behavior is more visible in newer than in older dwellings[12].Accordingly,oursamplemightbeappropriateto studyenergyconsumptionbehavior,becauseourdataiscollected ondwellingsbuiltafter1995.Inaddition,itseemsthatelectricity consumptionbehaviorrelatesfarless tothephysical character-isticsofahousecomparedtothatofheatingenergyconsumption, thereforeroutinesofelectricalapplianceusemightprovideuswith morearticulated insights intooccupant behavior. Thisresearch couldcontributetotheefforts,suchasWright’s[14],thatfocus onencouragingindividualsandhouseholdstowardsmoreenergy efficientbehavior.
Inourpreviouspaper[9],wereportedonthevarianceinthetotal electricityconsumptionandresearchedthedeterminantsofitin dwellingsintheNetherlands.Wefoundthatusingtheparameters of duration of useof general, hobby,food, and cleaning appli-ances,householdsize,gasconsumption,yearsofresidence,number ofbedrooms,dwellingtype,numberofshowers,dryers,washing machineloads,andoutsideworkinghours,wecouldexplain58% ofthevarianceinelectricityconsumption.Inthispaper,weusethe samesampleanddataweusedinourformerwork.Ourfirstaim istofurtheranalyzethebehavioralaspectsofhousehold electric-ityconsumptionintheNetherlands.Forthis,westatisticallydefine behavioralpatternsandprofilesoflightingandelectricalappliance usageinrelationtoelectricityconsumption.Further,weidentify thehouseholdandbuildingcharacteristics,alongwithcluesabout lifestylesandattitudes,whichprovidetheevidencetobuild behav-ioralprofiles.
Ourdata iscollectedbya survey from323dwellingsinthe Netherlandson[1]applianceownership,[2]presence inrooms, [3]activitiesofcooking,showerandbath,cleaning,[4]household compositionanddwellingcharacteristics.Existingresearchfocuses eitheronbehavioralpatternsusingthefirstthreegroupsofdata, oronbehavioralprofilesusingthelastgroupofdata.Oursecond aimistolinkthepatternsandprofilesusingthebehavioral fac-torsasacommondenominator, foundbyfactoranalysis,which couldhelptobetterdefineoccupantbehaviorincalculationsand/or simulationprograms.
2. Literatureandresearchquestions
Behavioral patterns and profiles have been defined with household characteristics [15–17], variables related to lifestyle [10,16–19], variables related to values, motivations, attitudes [11,20–23],and variables related mainlytoroutinesand habits [24–26].
Abreuetal.[27]adoptedaprofilerecognitionmethodtoidentify userprofilesofelectricityconsumption.Theelectricity consump-tiondatawascollectedwith15minintervalsfrom15housesovera periodrangingfrom3monthsto1year.Clusterswerethencreated usingprofilerecognitionoverthisquantitativedata.Households completedquestionnairestoself-reporttheirdailyroutines,and theusageprofilesthatwereobtainedwiththis‘qualitative’data werecomparedwiththe‘quantitative’clustersforvalidation.The studyshowedthatapproximately80%ofhouseholdelectricityuse canbeexplainedthroughrepeateddailyroutines.
Widenetal.[28]producedloadprofilesover5existing time-usedatasetscollectedinSwedenin1996,2006,and 2007.The numberofpeopleincludedinthesurveysvariedfrom13to431in 5to139households.Theactivitiesofpeoplewerereportednext tomeasurementsofelectricityand hotwaterconsumption.The dataresolutionvariedfrom5minto60min.Theactivityprofiles createdwithreporteddatawerecomparedtotheoneswith mea-sureddata.Theresultsshowedthathouseholdbehaviorprofiles regardingcooking,washing,lighting,TV,PCandaudiousecouldbe modeledusingtime-usedataofelectricityconsumption.However, hotwaterconsumptionwasnotsuccessfullymodeled.Itwasclear thatelectricityconsumptionwascloselyrelatedtooccupancyand thegroupingofappliancesaccordingtospecificactivities,andthis couldbeagoodwaytomodellingelectricityconsumption.
Colemanetal.[29]monitored14householdsintheUKbetween March2008 and August 2009. Thedwellings wereselected by snowballsampling,andtheyhadover220individualappliances. This researchfound that usage profiles varied widely between households in both sizeand make-up, and the average(mean) householdelectricityconsumptionfromICE(information, commu-nicationandentertainment)appliancesequatedtoaround23%of averagewholehouseelectricityconsumption(median18%).Ofthis, standbypowermodesaccountedfor11.5kWh,whichwasaround 30%ofICEapplianceconsumptionandaround7%ofaveragewhole houseelectricityconsumption.Colemanetal.foundthatdesktop computersandtelevisionsweretheappliancesthatconsumedthe mostelectricity,withmostoftheirconsumption occurring dur-ingtheactivepowermode.Audioappliances,printers,andother playandrecordequipmentweresignificantend-uses,largelydue tostandbyconsumption.Inoneofthehouseholds,computersthat werecontinuouslyactiveandconnectedtotheinternetwerealso foundtoberesponsibleforalargeportionofthesample’selectricity consumption.
O’Doherty etal. [30]analyzed thedeterminantsof domestic electricalapplianceownershipintheIrishhousingstock.Asurvey conductedin2001and2002on40,000housesrevealedthatnewer andmoreexpensivehouseshadmoreappliances,butalsomore EnergySavingAppliances(ESA).Yearsspentatthesameaddress
Table1
Applianceuse:Ownershipandduration(minutesperday).
CONTINUOUSLYUSEDAPPLIANCES CLEANINGAPPLIANCES
App M Max Min SD App M Max Min SD
Internet(wirelessrouter) 1 3 0 .56 Dryer N 1 1 0 .47
D 19 130 0 28.18
Telephone 1 8 0 1.13 Iron N 1 3 0 .27
D 17 150 0 23.78
Fridge 1 2 0 .35 Vacuumcleaner N 1 3 0 .39
D 16 90 0 23.85
Freezer 1 2 0 .56 Wash.machine N 1 1 0 .18
D 50 90 0 D
FOODPREPARATIONAPPLIANCES ICEAPPLIANCES
App M Max Min SD App M Max Min SD
Coffeemachine N 1 3 0 .47 TV N 2 6 0 .89
D 32 840 0 76.10 D 238 900 0 161.87
Toaster N 1 2 0 .53 PC N 1 5 0 .82
D 3 85 0 7.11 D 153 2880 0 309.12
Electricgrill N 1 2 0 .46 Laptop N 1 6 0 1.08
D 14 255 0 23.77 D 190 3060 0 369.92
Microwaveoven N 1 2 0 .36 Stereo N 1 4 0 1.07
D 10 85 0 13.51 D 104 720 0 147.9
Waterheater N 1 2 0 .35 DVDplayer N 1 3 0 .68
D 13 85 0 14.54 D 21 360 0 40.92
Cookerhood N 1 2 0 .42
D 30 180 0 32.84
Dishwasher N 1 2 0 .43
D 42 240 0 45.33
(N:numberofappliance;D:durationofuse;M:mean;SD:StandardDeviation).
decreasedtheownershipofESA.Likewise,householdersunderthe
ageof40hadthemostappliancesbutalsothemostESA.Dwellings
locatedindenseurbanareashadmoreESA.Lastly,more
subur-ban,terracedhouseshadtheleastESA.O’Dohertyetal.’sgroups
weredeterminedbasedonhouseholdanddwellingcharacteristics
together,howevernorelationshipwasresearchedbetweenthese
groupsandelectricityuse.
Genjoetal.[31] usedclusteranalysistogroup505Japanese
householdsin1996.Thisresearchdidnotnecessarilytrytoidentify thespecificcharacteristicsofthegroupsaccordingtotheir electric-ityconsumption,butsomedistinctfindingsoftheirresearchwere thatthepossessionofelectricalapplianceswasareflectionof resi-dents’lifestyle,largerandmulti-functionapplianceswerepopular amongJapanesehouseholds,andeconomicaffluencehadastrong influenceingroupingthehouseholdsaccordingtoapplianceuse andelectricityconsumption.
IntheNetherlands,researchonbehavioralprofilesregarding energyconsumptionfocusonheatingenergy.Evenifthisresearch is only on electricity consumption, it is insightful to see and compareours’tothestudiesthatanalyzedheatingenergy con-sumption in terms of the household characteristics, behavioral factors, patterns and profiles. Raaij and Verhallen [10] identi-fied5profilesofenergybehavior among145householdsinthe Netherlands: Conservers (higher education, smaller household size),Spenders,Cool,Warm(oldestgroup)andAverage.Theyfound nodifferencesregardingincomeandemploymentparameters.The researchofGrootet al.[16] andPaauw etal. [17]developed 4 profilesofenergyconsumption:convenience/ease(comfort impor-tant,nointerestineconomicsavings,energy,ortheenvironment (EEE));conscious(comfortimportant,interestinsavingsforEEE), cost(awarenessofeconomyandhenceenergyandthe environ-ment); and climate/environment (concern for EEE). Raaij [10], Groot[16]and Paauw’s[17] workfoundstatisticallysignificant differencesin energyconsumption amongtheirgroups.Vringer etal.’swork[23]groupedhouseholdsintheNetherlands accord-ingtoincome,age,educationandhouseholdsize.GuerraSantin’s research[12]revealed5groups(spenders,comfort,affluent-cold,
Table2
Specificappliancesownedbyapercentageofhouseholds.
Appliancename Numberofhouseholds Percentageofhouseholds
inthesample
Electricalcooker 107houses 36%
Gasfurnace 92houses 31%
Inductioncooker 87houses 30%
Solarium 24houses 8% Jacuzzi 8houses 3% Sauna 5houses 2% Waterbed 13houses 4% Aquarium 10houses 3% Terrarium 13houses 4% Close-in-Boiler 28houses 9%
Extraheating 14houses 5%
Ventilator 45houses 15%
AirConditioning 13houses 4%
Videocamera 64houses 21%
Videogames 60houses 21%
Homecinema 80houses 27%
Harddiscrecorder 69houses 23%
Videorecorder 98houses 33%
Otherappliances 33houses 20%
conscious-warm, conscious-cold) according tothe use of
heat-ingandventilationsystems,householdappliances,householdand
dwellingcharacteristics.Shedidnotfindstatisticallysignificant
dif-ferencesbetweenthebehavioralprofilesandpatternsintermsof
energyconsumption.
Existing research on behavioral patterns of electricity
con-sumptionfocusonparameters relatedto‘attitude,’ ‘motivation,’
‘lifestyle,’‘householdcomposition,’‘appliancepossession,’
‘house-hold and buildingcharacteristics.’ Methodologically, behavioral
patternsandprofilesareproducedeitherusingcontinuousdataon
actualbehavior(forexample[32–34])orbyclusteringbehavioral
profiles based oncross-sectional data abouthousehold charac-teristics (for example [12]), and some by combining both (for example [27–29]). In existing research, relationships between behavioral patterns,and household and buildingcharacteristics
haverarelybeeninvestigated.Ourworkcontributestothe liter-atureby[1]using(partially)continuousdataonactualbehavior as well as household and dwelling characteristics, [2] driving behavioralfactors,patterns,andprofiles,andlinkingthemtoeach other as well as looking for their relationship with electricity consumption.
Thereareseveralstudiesthatfocusonidentifyingthebehavioral patternsandprofilesforheatingenergyconsumption,butnoneon electricityconsumptionbehaviorinDutchhousingstock. Deter-miningbehavioralprofilescouldleadtomoreaccurateprediction ofelectricityconsumptionindwellings,betterplanningforthe tar-getedenergysavingmeasures,andhelpingenergycompaniesfor moreprecisecalculations.
3. Methodology
3.1. Researchframeworkandmethods
Inthispaper,wedefinedoccupantbehaviorasthepresenceina space,theuseoflightingandappliances,andtheactivitiesathome thatdirectlycauseelectricityconsumption.Figs.2and3displaythe researchframeworkandmethodology.Westartedwithananalysis oftheapplianceuseinthedatabase.Throughadescriptiveanalysis, wereportedthemaximum,minimumandmeanlevelsof owner-shipanduseofappliancesinthedatabase(Section4.1,Table1). Secondly,weresearchedtheeffectofoccupantbehavioron elec-tricityconsumptioninthedatabase,throughcorrelationanalysis betweenthebehavioral,householdanddwellingcharacteristics, occupantpresence,electricityconsumption(Section4.2,Table3).
Instepthree,weconductedexploratoryfactoranalysisto deter-minethefactorsunderlyingbehaviorofelectricityconsumption (Section4.3,Table4,Fig.4).Behavioralfactorsareclustersof vari-ablesthatconstitutethedriversofbehavior.Followingthefactor analysis,thehouseholdvariablesweredichotomizedaccordingto theirscoresforeachbehavioralfactor(belowthemean=0,above themean=1),whichmeantthateachhouseholdhada‘0’or‘1’score foreachfactor,andeachhouseholdhadastringcomposedof‘0’sor ‘1’s.Categorizingthehouseholdsaccordingtothecommonstrings, thebehavioralpatternsweredefined(Section4.3,Table5,Fig.5).
Instepfour,thebehavioralfactorswereusedincorrelation anal-ysis,inordertofindouttherelationshipbetweenbehavioralfactors andhouseholdanddwellingcharacteristics.Thehouseholdswere distributed intogroups based onthecorrelationoutputs, these groupsweretheuserprofiles(Section4.4,Tables6and7,Fig.6). Lastly, we looked for the relationship between the behavioral factors,patternsandthebehavioral profiles(Section4.5,Fig.7). Following,therelationshipbetweenbehavioralpatterns,profiles andenergyconsumptionwasdetermined(Section4.6,Fig.8). 3.2. Data:explanationofdata,outliers,transformedvariables
Thestudydatawascollectedviaasurveyintwodistricts (Water-ingseVeldandLeidscheRijn)intheNetherlandsonlyintheWinter of2008.Thedatabaseof323casescovered arangeoftopics in theformofaquestionnaire,withregardtohousehold characteris-tics(size,composition,yearsofresidenceinthedwelling,changes inhouseholdcompositioninthepreviousyear),individual char-acteristics(age, education, occupation, hoursspent outside the home),economic characteristics (income,ownership, electricity tariff),presence (numberof people and duration of occupation ineachroom), dwellingcharacteristics(type,number ofrooms, functionofrooms),applianceuse(numberofdomesticappliances, numberofappliancesinthelivingroom,standbyappliances, charg-ers,durationofuse,appliancelabels,sizes),andlightingdevices (number,type).
3.2.1. Outliers
Outlierswereanalyzedandvariablefrequencieswerechecked toseehowmanyofthevariablescouldbeusedforstatistical analy-sis.Outofthe323casesinthedatabase,theelectricityconsumption dataforsevenwereexceptionallyhigh,probablybecausethe occu-pantsdidnotactuallyrecordtheelectricityconsumptioninthe pastyearbutwrotethemeterreading.Twelvequestionnaireswere returnedblank.These19caseswerethereforeexcludedfromthe database,leavingafinalsamplesizeof304.
3.2.2. Missingdata
Someofthedatainthedatabasewereinsufficienttobeincluded inthestatisticalanalysis,hencewerenotincluded,namely: • Thenumberofweekswhennobodyisathome;
• Whethertheelectricityandgasmeterswerecheckedregularly • Appliancelabels
3.2.3. Transformedvariables
The‘electricitytariff’cantaketwovaluesintheNetherlands: [1]singletariffconsumption−onedaytimeandeveningrateon weekdaysandweekends[2],doubletariffconsumption−two dif-ferentrates,oneforduringthedayandanotherforevenings,nights andweekends.Theelectricityconsumptiondataobtainedfromthe surveywerebasedonkWhvalues. Somecaseshadsingletariff consumption records(9%),and somehaddouble records(91%). Toobtainafinalvariableforelectricityconsumption,acheckwas performedtodeterminewhetherasingleordoubleelectricity tar-iffmadeadifference.Nosignificantcorrelationwasfound,sothe singleandthedoubletariffrecordingswerecomputedtoone elec-tricityconsumptioncategory.
Therespondentsretrospectivelyreportedtheirhourlypresence athomeandindifferentrooms,duringtheweek.Thisdatawas transformedintototalhourlypresenceinroomsduringthe morn-ing,theday,theevening,thenightandallday.
Intermsofthenumberofappliancesowned,andtheduration ofuseoftheappliances,weconductedtwotransformations.First, inordertoobtainatotalfigureofdurationofuse,wemultiplied thenumberofappliancesinthehousewiththedurationofuse ofeach.Secondly,weaddedupthetotaldurationofuseof appli-ancesperfunctionofgroup.Wecreated4groupswithfunctions of ‘InformationCommunicationEntertainment (ICE)’, ‘Cleaning’, ‘Foodpreparation’and‘Continuouslyused’appliances(Table1).
Following,theresultsofthestudyarereportedin4Sections: 1.Descriptiveanalysisonappliance ownershipanduse;(2)the impactofoccupantbehavioronelectricityconsumption;(3) behav-ioralfactors,patterns,andprofilesofelectricityconsumption;as wellas(4)therelationshipamongthem.
4. Results
4.1. Applianceusebehavior
Themean,maximumandminimumnumberofeachappliance inthesample,andtheirdurationofuse(minutesperday)were reportedandcategorized in4 groups,i.e.‘Information Commu-nicationEntertainment (ICE)’, ‘Cleaning’, ‘Foodpreparation’ and ‘Continuouslyused’appliances(Table1).Onaverage,therewere 21appliancesinahouseand5oftheseapplianceswereinthe liv-ingroom.Theaverageelectricityconsumptioninoursamplewas 3058.57kWh/year.
Onaverage, therewasafridge,afreezer,a wirelessinternet router,andatelephonethatworkedcontinuouslyineachhouse.As forcleaningappliances,adishwasherandadryer,avacuumcleaner andanironwereusedineachhouseinthesample.ICEappliances
Dwelling characteristics Household characteristics Lifestyles Attitudes Lighting behavior Electricity consumption Determinants of behavior Presence Aplliance use behavior Electricity consumption related behavior Electricity consumption related behavior
Fig.2. Researchframework.
Behavioral variables
Energy consumption Household characteristics
Dwelling characteristics
Correlation St. signific
a nt behavioral variables Factor Analysis Behavioral factors Behavioral patterns Correlation Energy consumption
Correlation Anova Correlation Anova Section 4.2 Section 4.4 Section 4.3 Section 4.6 Section 4.5 Section 4.1 Behavioral profiles
Fig.3. Researchmethodology.
were2TVs,aPC,alaptop,aDVDplayer,andamusicplayer.Lastly, adishwasher,amicrowaveoven,atoaster,agrill,awaterheater, acoffeemaker,andanexhausthoodcreatedthesetoffood prepa-rationappliancespresentineachhouseonaverage,inoursample. Exceptforcontinuouslyused,alltheappliancegroupswesetup refertoaspecificfunction/activityinthehouse.Besides,only‘food preparation’appliancesisacategorythatrelatetoaspecificroom (kitchen)inthehouse.
Someofthehousesalsoownedspecificappliances.The own-ershipand/ortheuseoftheseapplianceswerenothighenough, sowedidnotincludetheminthefactoranalysis.Thenumberof appliancestheypossessedwerereportedinTable2.
4.2. Effectsofoccupantbehavior,householdandbuilding characteristicsonelectricityconsumption
Correlationanalyseswerecarried outtodeterminethe rela-tionshipbetweenoccupantbehaviorandelectricityconsumption (Table3).Thefirstsetofvariablesconsideredweretheuseof house-holdappliances.ICE(Information-Communication-Entertainment) appliancesappearedtohavethemostsignificantinfluenceon
elec-tricityconsumption(r=0.98***),whichwasfollowedbythetotal durationof useofhouseholdcleaning(r=0.13**),food prepara-tion(r=0.09*)andcontinuouslyused(r=0.02*)appliances.Inthe survey,respondentswerealsoaskedtoreporttheirbehavioron theweeklyuseofappliances,andthetotaluseparticularlyinthe livingroom,howeverthesevariables didnot seemtobe corre-latedtoelectricity consumption,hencetheywereomittedfrom theanalysis.
Secondly, the influence of the use of stand-by and battery charged appliances, and the ownership of energy saving, non-energy saving lamps, and PV/solar panels were analyzed. The mostsignificantimpactonelectricityconsumptionwasbyhalogen lamps(r=0.17**).Theuseofbatterycharged(r=0.22*),and stand-by (r=0.15*) appliances had a positive influence on electricity consumption,whileenergysavinglamps(r=−0.04*),andPV/solar panelshadanegativeone.TheownershipofPV/solarpanelsdidnot, infact,significantlycorrelatewithelectricityconsumption, how-everthisparameterwasincludedinthefactoranalysis,tosetup behavioralpatternsandprofiles.
Theuseofmechanicalventilationwasnotfoundtobecorrelated withelectricityconsumption, buttheuseofshower(r=0.23**),
Fig.4.Behavioralfactorsandthevariablesthatdeterminethesefactors.
Table3
Descriptiveandcorrelationanalysisofhouseholdanddwellingcharacteristics,occupantbehaviorandelectricityconsumption.
Variable Definition Numberof
cases Meanand Standard Deviation Correlation Electricity Consumption
Householdappliances Continuouslyused Totaldailydurationofuseofcontinuouslyusedappliances H:118 M:4895.58 0.02*
L:164 SD:2414.45 N:282 Foodpreparation Totaldailydurationofuseoffoodpreparationappliances H:107 M:238.77 0.09*
L:175 SD:176.26 N:282 Householdcleaning Totaldailydurationofuseofhouseholdcleaning
appliances
H:99 M:116.98 0.13** L:183 SD:105.88 N:282 ICE TotaldailydurationofuseofICEappliances H:89 M:1457.92 0.98*** L:193 SD:1376.59 N:282 Stand-by Totalnumberofstand-bymodeofappliances H:120 M:2.75 0.15*
L:174 SD:3.06 N:294 Batterycharged Totaldurationofbatterychargedappliances H:65 M:67.5 0.22*
L:239 SD:140.11 N:304 Energysavinglamps Numberofenergysavinglamps H:104 M:5.89 −0.04* L:190 SD:6.05 N:294 Halogenlamps Numberofhalogenlamps H:117 M:14.52 0.17**
L:177 SD:10.07 N:294 PV/Solarpanel PresenceofPVorsolarpanels Y:46 M:0.15 −0.79(r:0.23)
N:248 SD:0.36 N:294 Hotwashcycles Totalweeklynumberhotlaundrycycles H:62 M:0.94 0.19**
L:230 SD:1.50 N:292 Showers Totalweeklydurationofshowersinthehousehold H:122 M:139.21 0.23**
L:182 SD:135.28 N:304 Bath Totalweeklynumberofbathsinthehousehold H:90 M:1.33 0.14*
L:214 SD:2.59 N:304 Presence Room1 Totalhoursofpresenceinroom1(weekdays/allday) H:167 M:13.61 0.22*
L:109 SD:5.35 N:294 Room2 Totalhoursofpresenceinroom2(weekdays/allday) H:111 M:5.18 0.31*
L:165 SD:4.08 N:294 Room3 Totalhoursofpresenceinroom3(weekdays/duringthe
day)
H:20 M:0.97 0.12* L:259 SD:0.20 N:294 Livingroom-Kitchen Totalhoursofpresenceinlivingroom-kitchen
(weekdays/morning)
H:85 M:2.52 0.21** L:188 SD:2.11 N:294 Bathroom Totalhoursofpresenceinbathroom(weekdays/morning) H:91 M:1.28 0.18**
L:182 SD:1.17 N:294 Household
characteristics
Householdsize Householdsize H:115 M:2.53 0.38**
L:183 SD:1.17 N:301 Yearsofresidence Yearsofresidenceinthesamehouse H:151 M:5.38 −0.16* L:136 SD:3.13 N:287 Age Presenceofagegroup6–65inthehousehold Y:214 M:3.00 −0.72* N:84 SD:0.75 N:298
Income Monthlyhouseholdincome H:171 M:3.99 0.13*
L:113 SD:1.04 N:284 Education Amemberofthehouseholdhasuniversityorhigher
education
Y:32 M:5.46 −0.03(r:0.22) N:270 SD:2.03 N:302 Workingoutside Hoursspentoutsidethehouse H:178 M:23.60 0.97(r:0.13)
L:124 SD:14.03 N:302 Dwel.C. Dwellingtype Typeofdwelling(corner/self-standinghouse,topfloor
apartm.)
Y:46 M:2.95 −0.23* N:255 SD:1.05 N:301
Bedrooms Numberofbedrooms H:85 M:1.84 0.26**
L:218 SD:0.97 N:303 Notesoncasesandabbreviations:
H:Numberofcasesthathavehighervaluethanthemeanvalue. L:Numberofcasesthathavelowervaluethanthemeanvalue. Y:Numberofcasesthathavepositiveresponsetothequestion. N:Numberofcasesthathavenegativeresponsetothequestion. Householdincome:Hmeanshigher(LforLower)than56000Euros.
Age:Meanvalueofagegroupsinthesampleis“16–65yearsold.”However,forcategorizinghouseholdsintermsofelectricityconsumption,weexpandedthegroupto(1) ‘6–65yearsold;’and(2)‘childrenandelderly.’
Dwellingtype:Themeanvalueof2.95meansrowhouseisthecommontypology.Forcategorizinghouseholdsintermsofelectricityconsumptioninouranalysis,we re-categorizedthisvariableaccordingtohowmuchthedwellingmightbereceivingdaylight.Thus,wecreatedtwogroups(1)corner,orself-standinghouses,ortopfloor flats;and(2)rowhouse,orgroundormiddlelevelhouses.
*p<0.05. **p<0.01. ***p<0.001.
bath(r=0.14*)andthenumberofhotlaundrycycles(r=0.19**) were.Showerswerecalculatedintermsofthetotaldurationof showersperweekin thehousehold,andbathin termsof total numberofthemperweekinthehousehold.
Presenceinrooms(otherthanthelivingroom)werepositively correlatedwithelectricityconsumption.Thecorrelationanalysis showedthatthepresenceinroom1(r=0.22*)androom2(r=0.31*) allday,room3(r=0.12*)duringtheday,andlivingroom/kitchen
Table4
Factorscoresandcommunalities(principlecomponentsanalysis).
Variables Components’factorscores Communalities
Factor1 Factor2 Factor3 Factor4 Factor5
Continuouslyused 0.588 0.677 Foodpreparation 0.509 0.527 Cleaning 0.468 0.645 ICE 0.721 0.631 Stand-by 0.493 0.525 Batterychargers 0.624 0.676
Energysavinglamps 0.429 0.704
Halogenlamps 0.530 0.754
PV/Solarpanel 0.515 0.552
Hotwashcycles 0.448 0.755
Dryer 0.522 0.742 Dishwasher 0.562 0.677 Showers 0.577 0.325 0.695 Bath 0.432 0.589 Room1 0.487 0.491 Room2 0.660 0.573 Room3 0.406 0.602 Livingroom-Kitchen 0.617 0.605 Bathroom 0.657 0.617
Rotationmethod:VarimaxwithKaiserNormalization(formoreexplanationontherotationmethod,seereference35).
Factorscores<0.4aresuppressed.
Table5
Distributionsofcases(N)andstringsaccordingtofactors,andDerivationofbehavioralpatterns.
Nameofpattern Factor1Total
applianceuse Factor2 Articulationof technology Factor3Spatial Presence Factor4 (Personal) Cleaning Factor5Energy conservation Numberofcases thatconstitutea string 1.Applianceuse 111 101 010 101 100 212423 2.Presence/Technology 1111 1111 1100 1010 0100 25222621
3.Presence/(Personal)Cleaning 1111 1010 1111 1111 0100 19231822
4.Energyconservation 11 01 01 00 11 1820
Table6
Correlationsbetweenhouseholdanddwellingcharacteristicsandbehavioralfactors.
Householdanddwellingcharacteristics FactorScore1 FactorScore2 FactorScore3 FactorScore4 FactorScore5
Total applianceuse Articulationof technology Presence (Personal) Cleaning Energy Conservation
Dwellingtype(corner/free-stand/topfloor) PearsonCorrelation −0.18 −0.07 – −0.03 −0.04
Significance(2-tailed) 0.03 0.38 – 0.05 0.05
Numberofbedrooms(otherthanlivingroom) PearsonCorrelation −0.17 0.31 – 0.08 0.10
Significance(2-tailed) 0.06 0.00 – 0.03 0.24
Yearsofresidenceinthesamehouse PearsonCorrelation 0.01 −0.03 – 0.00 0.03
Significance(2-tailed) 0.93 0.68 – 0.92 0.70
Householdsize PearsonCorrelation −0.16 0.36 – 0.17 −0.11
Significance(2-tailed) 0.05 0.06 – 0.02 0.02
Presenceofchildrenorelderly PearsonCorrelation 0.13 −0.19 – 0.14 0.04
Significance(2-tailed) 0.15 0.09 – 0.01 0.60
Educationlevel(highestlevelinthehousehold) PearsonCorrelation −0.01 0.01 – −0.10 −0.03
Significance(2-tailed) 0.89 0.05 – 0.26 0.04
Hoursspentoutsidethehouseforwork PearsonCorrelation 0.09 0.10 – 0.08 −0.05
Significance(2-tailed) 0.31 0.03 – 0.02 0.05
Incomelevel PearsonCorrelation −0.50 0.11 – 0.09 −0.01
Significance(2-tailed) 0.05 0.02 – 0.04 0.90
Table7
Behavioralfactorsandbehavioralprofiles.
Factor NameofFactor CorrelatedHousehold/Dwellingvariable
Factor1 Totalapplianceuse -(Oldercouple)-Middle-groundfloordwelling-Lowerincome-Moreworkoutside-Householdsize(<2)
Factor2 Articulationoftechnology -Numberofbedrooms-Workathome-Higherincome-Householdsize(=>2)
Factor3 Spatialpresence –
Factor4 (Personal)Cleaning -Numberofbedrooms(>2)-Householdsize(>2)-Workathome-Higherincome-Younghousehold
Fig.6.Household/dwellingcharacteristics,behavioralfactors,andprofiles.
(r=0.21**)andbathroom(r=0.18**)inthemorningwerepositively
andsignificantlycorrelatedwithelectricityconsumption.
4.3. Behavioralfactorsandpatterns
Afactorcanbedescribedwithitsmeasuredvariablesandtheir
relativeimportancetothatfactor[35].Therelationshipamong
dif-ferentvariablesinadatabasecanbedescribedusingfactoranalysis, byexploringthefactorsthathelptoidentifytherelatedbehaviors. Weusedexploratoryfactoranalysistoidentifybehavioralfactors underlyingelectricity consumption. We used thevariables that weresignificantlycorrelatedtoelectricityconsumption(Table3). However,someofthevariablesthatwerenotsignificantly corre-latedtoelectricityconsumptionwerestillincludedintheanalysis, consideringthattheymight revealfurtheraboutthebehavioral patterns.
Accordingly, 19 variables were used for the factor analysis. Tostartwith,wecheckedifthefactor analysiswassuitablefor oursample:Thecorrelationsignificance andthecoefficient val-ueswerecheckedbetweenthedifferentvariables.Majorityofthe significancevaluesweresmallerthan0.05andcoefficientvalues werelowerthan0.9,whichmeantthattherewasreasonable fac-torability,hencenoneofthevariableswereeliminatedfromthe analysis.Thedeterminantvaluewas0.00239,whichwasgreater than0.00001,thereforemulticollinearitywasnotaproblemfor thedata.Next,theKaiser-Meyer-Olkin(KMO)measureofsampling adequacy,andBartlett’stestofsphericitywerecontrolled.TheKMO valuewas0.73,andBartlett’stestwashighlysignificant(p<0.000) showingthatfactoranalysiswasappropriatetoanalyzeour sam-ple.Oursamplesizewasgreaterthan250, wehadlessthan30
variables,andmostoftheircommunalitiesafterextractionwere around0.7,aswellastheiraveragecommunalitywas0.67(which wasgreaterthan0.6),thereforeweretainedallfactorsthathave Eigenvaluesabove1(See[35]foradefinition,andmore explana-tiononKMOmeasure,Bartlett’stestofsphericity,andEigenvalue infactoranalysis).
Basedoneachvariable’sprimaryscoreoneachfactor,thefactor scoreswerecreatedforthefactors.Table4displayedtheanalysis resultsintermsofthevariablesdefiningeachofthefivefactors, aswellasthefactorloadingmatrixandtheircommunalities.The initialEigenvalues,i.e.degreeofvariationinthetotalsample cre-atedbyeachfactor,displayedthatthefirstfactorexplained16.29% ofthevarianceinelectricityconsumption,thesecond15.23%,the third13.79%,thefourth9.00%,andthefifth7.84%,creatinga cumu-lativeof62.15%.Factors6–19wereabletoexplainaround3–4%of thevarianceeach.Accordingly,thefirst5factorswerechosento usefurtherinthestudy.Thesefactorswerenamedas:‘total appli-anceuse,’‘articulationoftechnology,’‘spatialpresence,’‘(personal) cleaningbehavior’and‘energyconservation’(Fig.4).
Accordingly,Factor1 wasmerelyaboutthetotaldurationof applianceuseinthedwellingandcomprisedofthecontinuously used,foodpreparation,andcleaningappliances.Factor2wasabout theuseofInformation, CommunicationandEntertainment(ICE) appliances,andtheuseofstandbyandbatterychargedappliances. Thisfactorimpliedamoretechnologyanddeviceorientedlifestyle, aswellashome-office workingpreferences.Factor3related to thepresenceoftheoccupantsintherooms,inthekitchen/living roomandthebathroom,andtheintensiveuseofhalogenlamps. Factor3pointedtotherelationshipbetweenspatialuseathome andelectricityconsumption.Halogenlampsemphasizedtheless
Fig.7.Relationshipsfoundbetweenhousehold/dwellingcharacteristics,behavioralfactors,patterns,andprofiles.
Notes:Outersquare/Edges=behavioralpatterns.Centerpentagon/Edges=behavioralfactors.Innersquare/Edges=behavioralprofiles.Lines=household/dwelling charac-teristics(tothebottomandleftcharacteristicsthatarerelatedwithlesselectricityconsumption;tothetopandrightcharacteristicsthatarerelatedwithmoreelectricity consumptionaredistributed.)
2000 2500 3000 3500 4000 4500
appliance presence/ presence/ energy use technology [personal] cleaning conservation kWh/year 2000 2500 3000 3500 4000 4500 kWh/year
family techie comforty conscious
energyconsciousattitudeagainsteverydaylife.Factor4relatedto theintensivelaundryandpersonalcleaninghabits.Thenumberof hotwashes,theuseofdryeranddishwasher,aswellasthe dura-tionofshowers,andthenumberofbathspointtothesignificanceof theinfluenceofcleaninghabitsonelectricityconsumption.Factor 3and4alsohintedattherelationshipbetweenoccupantcomfort andelectricityconsumption.Factor5relatedtolessuseof elec-tricity.Thevariablesthatdefinedthisfactorweretheownership ofPV/solarpanels,energysavinglamps,and thelaundryhabits, wheretheownershipofPV/solarpanels,energysavinglamps,as wellasthedecreasingnumberofdryerandhotwashingcycleshad anegativeinfluenceonelectricityconsumption.
Todeterminethebehavioralpatterns,firstwedichotomizedthe factorscoresofthecasesinoursample.Wedidthisbycomparing eachcase’sfactorscoretothesample’smeanfactorscoreobtained fromthefactoranalysis(ifabove=1,ifbelow=0).Thenwerepeated itforthefivefactors.Throughthis,thefivedichotomousscoresfor eachcaseinthesample,i.e.eachhousehold,createdastring.The clusteringofallstringsrevealedthirteencategories(Table5).
Afterwards,thesecategorieswereclusteredoncemore, accord-ing to the correlation between the behavioral variables that composethefactorsandelectricityconsumption(seeTable3for thecorrelationanalysis). Eventually,thirteenstringswere orga-nizedinto4patterns(Fig.5):Pattern1:(Applianceuse),Pattern 2:(Presence/Technologyoriented),Pattern3:(Presence/Comfort oriented),Pattern4:(Energyconservation).Table5 showedthe behavioralpatterns,thefactors,andthedistributionsofthestrings foreachbehavioralpatternandfactor.
4.4. Behavioralfactorsandprofiles:Householdandbuilding characteristicsrelatedtobehavioralfactors
In ordertodeterminethe behavioral profilesin thesample, weanalyzedthebehavioralfactorsintermsoftheircorrelationto thehouseholdandbuildingcharacteristics.(Table6).Wesawthat spatialpresencewasnotattachedtoacertainhouseholdand/or dwellingcharacteristic,howeveritcomplementedprofile2and3. AnalyzingTable6,wefoundthehouseholdprofilesof‘family,’ ‘techie,’‘comforty,’and‘conscious,’whichwereexplainedfurther withinthedescriptionsoftheprofilesinthenextparagraphs,and inTable7,Fig.6.
Theresultsshowedthatthehouseholdsthathadhigh correla-tionvaluesforfactor1:‘applianceuse’weremostlyyoungcouples, except thefew cases of the elderly.These households had the averagebehavior,bothintermsofownershipandusageof contin-uouslyused,foodpreparationandcleaningappliances.Theylived ongroundormiddlefloorapartmentorrowhouse,whichinfluence thenaturallightlevelinthehouse(hencetheelectricity consump-tion).The householdshad slightlylower incomeinsomecases, comparedtotheotherprofiles.Wecalledthisprofileas‘family.’
Thehouseholdvariablesthatrelatedtofactor2:‘articulationof technology’hadhighereducationlevel,higherincomelevel,and insomecases,lowerhoursofworkingoutside.Variablesrelatedto householdcompositiondidnotappearcorrelatedwiththisfactor, butthisprofilehadyoungsingleorcouplehousehold.Oneorboth membersofthehouseholdprobablyhadaflexibleworking sched-ule,andpossiblyfreelancingand/orworkingathome.Thehigher educationandlesshoursofworkingoutsidewaspotentiallyrelated tothehigheruseofICEappliances,stand-byandbatterycharged appliances.Thishouseholdtypewasalsorelatedtofactor3‘spatial presence,’i.e.bedroom3(label3referstotheextrabedroom,or extrafunctionofthebedroomotherthansleeping)andbathroom. Theuseofbedroom3duringthedayconfirmedworkingathome orhome-officeconfiguration.Theuseofbathroominthemorning mightberelatedtoshowerandotherpersonalcleaningbehavior, howeverthefactorof‘personalcleaning’wasnotfoundcorrelated
withthisprofile.Wenamedthisprofileas‘techie.’Thisgroupalso hadthelargestnumberofharddiscrecorders,videocamerasand videorecorders,whichwerenotincludedintheanalysisbecause oftheirsmallamountinthesample.
ThevariableswhichwererelatedtoFactor4((personal)cleaning behavior),weredwellingtypology(cornerorfreestanding), num-berofbedrooms,andahouseholdprofileofhigherincomelevel, biggerhouseholdsize,andlesshoursofworkingoutside.Thisgroup livedinlargerhouseswithmorethanonebedroom,oneormore children,andpossiblyoneoftheparentsorbothparents-parttime stayedathome.Thisgroupcameforwardwithitsintensiveuseof appliancesthatrelatedtodwellingand/orhouseholdcleaning,i.e. durationofshowers,numberofbaths,dishwasheruse,numberof hotlaundrycyclesanddryerloads.InadditiontoFactor4,thisgroup wasalsorelatedtoFactor3,presenceinbedroom1and2,which complementedthecorrelationwiththevariablesofthenumber ofbedroomsandworkinglesshoursoutside,andpresencein liv-ingroomandkitchen.Thisgroupalsousedmorehalogenlamps, whichpointstolessinterestinenergysaving.Wenamedthisgroup ‘comforty.’Thisgrouphadthelargestownershipofinductionand electricitycooker,waterbedandairconditioning,videogamesand homecinema,whichwerenotnormallyincludedintheanalysis becauseoftheirrelativelysmallnumberintheentiresample.
ThishouseholdprofilerelatedtoFactor5‘energyconservers,’ whichmeantmoreuseofenergysavinglamps,andownershipofPV and/orsolarpanels,howevertheseparametersdidnotappear sig-nificantlycorrelatedwiththefactor.Thehouseholdprofilehadless useofshowercomparedtootherprofiles,anditusedlessofdryer andhotlaundrycycles,whichrelatedtoFactor4‘(personal) clean-ingbehavior.’Thishouseholdprofilehadhighereducationlevel, workedmorehoursoutsidethehouse,hadsmallerhouseholdsize, andlivedintopfloorapartmentorcornerhouseinsomecases.The profiledidnotincludeasignificantlycorrelatedincomeparameter, butithadmoreincomethanprofile‘family,’andlessincomethan profile‘techie’and‘comforty.’Wecalledthisgroupas‘conscious.’
4.5. Relationshipsbetweenbehavioralpatterns,profiles,and factors
Fig.7showedhowthebehavioralfactors,patterns,profiles,and characteristicswererelatedtoeachother.Thebehavioralpatterns formedtheouterlayer,thebehavioralfactorsformedthemiddle pentagon,andthebehavioralprofilestheinnersquare.Theouter squarerepresentedthebehavioralpatterns.Astopandrightmeant moreuseofelectricity,theleftandbottommeantlessuseof elec-tricity.Themiddle pentagonshowedthebehavioral factors,i.e. total applianceuse,articulation oftechnology, (personal) clean-ing,andenergyconservation.Thebehavioralpatternsandfactors seemedtobeconsistent,exceptforthefactor‘presence,’which appearedbothwithin(personal)cleaningandtechnologypatterns. Whenelectricityconsumptionandunderlyingbehavioralfactors areconsidered,thepatternsof‘presence/technology’and‘energy conservation’seemedtooppose,aswellas’(personal)cleaning’ and‘useofappliances.’
Householdprofilesof‘conscious’and‘techie’seemedtooppose, when thehouseholdand dwellingcharacteristicsrelated tothe behavioralfactorsweretakenintoaccount.Forinstance,conservers worked more hours outside compared to techies, and seemed tolive in dwellingsthat get moreday light. Techieshad more householdincome.Bothgroupshadhigheducation,althoughonly forconserversthisvariablewassignificantlycorrelatedwiththe behavioralfactors.Similarly,‘comforty’and‘family’opposedwith eachother.‘Comforty’wasofyoungerhouseholds,whohadhigher incomeandhighernumberofchildren,spentmoretimeathome
andhadbiggerhouses.‘Family’wasolder,smallerinhouseholdsize andincome,andspentlesshoursathomeingeneral.
4.6. Relationshipsbetweenbehavioralpatterns,behavioral profiles,andelectricityuse
Thecorrelationanalysisbetweenbehavioralfactorsand elec-tricityconsumption revealed that factor 1 (appliance use) was correlated with electricity consumption r=0.11, p<0.05; factor 2(articulationoftechnology)byr=0.35,p<0.00;factor3 (pres-ence)wasnotsignificantlycorrelatedwithelectricityconsumption (r=0.14,p<0.15);factor4(personal)cleaningbyr=0.37,p<0.00; andfactor5(energyconservation)wassignificantlycorrelatedwith electricityconsumption(r=0.13,p<0.05).Thesefactorswereused todefinebehavioralpatterns.
For determining the differences in electricity consumption for each behavioral pattern, we conducted a one-way Anova test,wherewefoundstatisticallysignificantdifferences(r=0.17, p=0.02).Boththestatisticallysignificantdifferencesamong behav-ioralpatterns,andthesimilaritiesbetweenourresultswiththose oftheliteratureshowedthatourresearchmightbeusedfurtherfor researchonelectricityconsumptionandoccupantbehavior.Fig.8 showedtheenergyconsumptionforeachbehavioralpattern(left). Following,welookedatthebehavioralprofilesinrelationto electricityconsumption(Fig.8(right)).‘Family’hadahighscore forapplianceuse,‘techie’(technologyorientedsingles/coupleswho alsoworkedathome)hadahighscoreforarticulationoftechnology andpresence,‘comforty’(largefamilieswithhighpreferencefor comfort,showers,baths,dryer,etc.)hadahighscoreforpresence and(personal)cleaning,and‘conscious’(singlesorcoupleswith higheducationandworkingoutside)forenergyconservation(PVs, energysavinglamps,etc.).Wefoundstatisticallysignificant differ-encesamongthefourprofilesintermsofelectricityconsumption (r=0.19,p=0.02).
5. Discussion
In this paper, we aimed to analyzein detail thebehavioral aspectsofhouseholdelectricityconsumptionintheNetherlands. Inthissection,wepresentadiscussion[1]ontheappliance own-ership,useanddailylife;[2]ontheresultsoffactoranalysis,i.e. thebehavioralfactors,patternsandprofiles,andtheirrelationship withelectricityconsumption;[3]onthecomparisonofourresults withtheexistingresearch;and[4]onmethodology.
5.1. Applianceownership,useanddailylife
Intermsofownershipofappliances,everyhouseholdowning adryer,aseparatefreezer,and6batterychargedappliancesisa remarkableresult.Presenceinrooms/athometellsusaboutthe timesofthedaythattheappliancesareused.Ingeneral,itcouldbe saidthatmostappliances,exceptforICEareusedinthemorning (07:00–09:00),andtheevening(18:00–20:00).
Inoursample,everyhouseholdhasonaverage2TVs,1desktop computer,1laptop,1stereosystemand1DVDplayer.Some house-holdshave1TVand1laptopperperson.Thetotaldailyhoursspent watchingTVis4honaverage,PCuseperdayisapproximately2and ahalfhours,andlaptopuse3h.ThissuggestshowcentralTVsand computersaretoourlives.TVsarethemostimportantelectricity consumersathome,theenergyefficiencyofwhichhaven’tbeen improvedaswellastheotherappliances.Whenwethinkofthis togetherwiththenumberofbatterychargedappliances,wecould saythepossessionanduseofICEapplianceswillbeveryimportant forpolicyeffortsinreducingelectricityconsumptioninfuture.
Asforcleaningappliances,adryerisused2timesperweekand awashingmachine5times.Thesenumbersshowthatalmostevery
itemofclothingiswornonlyoncebeforeitiswashed.Whenthis isconsideredtogetherwiththe17minuseoftheironperdayand theonceortwiceshowersperpersonperday,ittellsusaboutthe occupationsand/ortheintensecleaningandcomfortpreferences ofthehouseholds.
Intermsoffoodpreparationappliancesperhousehold(on aver-age), thefact that there is a freezer in continuous usetells us aboutfoodstoring/eatinghabits.Perhapslessfreshfoodisbeing consumedand/orhouseholdsmightalwaysbepreservingfoodfor winter/summer.Thegrillandmicrowaveovenbeingused24min in total per day suggeststhat themain meals consist of easy-to-preparefood.Lastly,adishwasherisused42minperdayon average,whichmeansthateitherthedishwasherisusedonthe quickcycleeveryday,orthelongcyclenearly4timesaweek. 5.2. BehavioralFactors/Patterns/Profiles
Using exploratory factor analysis, we found the behavioral factorsastotalappliance use,articulation oftechnology,spatial presence,(personal)cleaningbehavior,andenergyconservation.In consistencewiththebehavioralfactorswefoundthe4behavioral patternsas theuseof appliances,presence/(personalcleaning), presence/technology,energyconservation.Following,the house-holdanddwellingcharacteristicswereincludedintheanalysis,and thebehavioralprofileswererevealedas‘family’,‘techie’,‘comforty’, and‘consciouss’.
Here we saw that the behavioral factor of spatial presence appearedintwobehavioralpatterns,i.e.cleaningandtechnology. WhiletheuseofICEappliancescreatedenoughfactorscoretorelate toaseparatebehavioralfactorandpattern,thebehavioralfactor ofpresenceappearedintwodifferentbehavioralpatterns ((per-sonal)cleaningandtechnology).Thepositiveornegativebehaviors of(personal)cleaninganduseofhalogenorenergysavinglights alsoleadtotwodifferentpatterns((personal)cleaningandenergy conservation).
Bydefininghouseholdcharacteristicsinrelationtobehavioral factors,andtherelationshipbetweenbehavioralfactorsand pat-terns,onecoulddeterminetheassociatedbehavioralfactorsand behavioralpatternsofa household.Forinstance,ifahousehold is partof the‘techie’ profile,we couldexpect a highscore for ‘articulationoftechnology’and‘presenceathome,’whichmeans working/beingpresenthighhoursintherooms,and usinga lot oftechnologicaldevices,includingICEappliances,stand-by,and batterychargedappliances.
Thehigherorlowervaluesofhouseholdsize,income,education, workingoutside,number ofbedrooms, anddwelling typewere foundtoberelatedtodifferentbehavioralfactors.Forinstance, the‘comforty’profilehadbiggerhouseholdsize,higherincomeand numberofbedroomscomparedto‘family,’whileithadlower work-ingoutsidehours.The‘conscious’profilewasfoundtohavemore hoursofworkingoutside,smallerhouseholdsize,andhigher edu-cation,comparedto‘techie,’andwasfoundtoliveinahousethat getsmoredaylight.Theprofile‘conscious’didn’tnecessarily cor-relatetoincome,butithadmoreincomethanprofile‘family,’less incomethan‘comforty.’Inoursample,consideringtheelectricity consumption,thebehavioral profilesdidnotrelatetoparticular householdstereotypessuchassingle,couple,elderly,etc.,butto variablessuchasworkinghours,householdsize,education,and income.
5.3. Comparisonwithliterature
OurresultsweresimilartothoseofWidenetal.[28]: Electric-ityconsumptioniscloselyrelatedtooccupants’presence.Besides, applianceusebasedonspecificactivitieslikecooking,washing, lighting,TVandPCusecouldbeagoodwaytomodeloccupant
behaviorandelectricityconsumption,andtherelatedprofiles.In ourresearch,wefoundthattheuseofICEappliances(articulation oftechnology)determinedabehavioralpatternonitsown. Cole-manetal.’sresearch[29]alsopointedtothesignificanceofICE appliances:“computersandTVsduringtheactivepowermode, andaudioappliances,printers,andotherplayandrecord equip-mentduringstandbyconsumptionaresignificantend-users(23%of electricityconsumption). ¨AccordingtoO’Dohertyetal.[30] house-holdersundertheageof40hadthemostappliancesbutalsothe mostenergysavingappliances(ESA).Inoursample,thetwogroups hadthemostnumberofapplianceswereyoungsingles,couplesor families,whichcompliedwiththeresultsofO’Dohertyetal.Lastly, Genjoet al.’s[31]analysisfoundthateconomicaffluencehad a stronginfluenceingroupingthehouseholdsaccordingto electric-ityconsumption.Incomewasoneofthehouseholdcharacteristics thatweusedtodeterminethebehavioralprofiles,aswell.
IntheNetherlands,theresearchonbehavioralprofiles regard-ingenergy consumption focusonheating energy,but still they areinsightfultocomparetoourworkintermsoftheirfindings. RaaijandVerhallen[10]identified5profilesofenergybehavior asconservers,spenders,cool,warmandaverage,andtherelated householdcharacteristicsashouseholdsize,education,and age. Grootetal.andPaauwetal.[16,17]developed4behavioral pro-filesbasedoncomfort,interestinenergysavings,andawareness ofeconomy.Vringer[23]groupedhouseholdsintheNetherlands accordingtoincome, age,educationandhousehold size.Lastly, GuerraSantin’sresearch[12]revealed5groupsaccordingtotheuse ofheatingandventilationsystems,householdappliances, house-holdanddwellingcharacteristics.Thevariablesofhouseholdsize, education,age,comfort,andincomewerealsothosethatweused insettingupthebehavioralprofilesinoursample.Wedidn’tlook intobehavioralattitudeslikeinterestinenergysavingorawareness ofeconomy.Intermsoftheprofilesdefined,‘conservers,’‘family,’ and‘comforty’arethebehavioralprofilesfoundinliterature,and visibleinourresults,aswell.Itmightbeinterestingtolookdeeper intotheseprofiles,sincetheymightrevealmoreaboutthecommon underlyingaspectsofbehaviorthatrelatetosimilarelectricityand heatingenergyconsumptionbehaviors.
5.4. Methodology
Technologicaladvancesanddecreasinghardwarepricesenable newresearchtoutilizesmartmetersandothercontinuousdata collectionmethods (for instance [32–34]).Research that works withthiskindofdatausesanalysistoolslikeprofilerecognition (forinstance[27]), timeuseanalysisandloadmodeling[28,36], eigendecomposition(for instance[37])andMarkovchains(for instance[38]).Ourresearchemployeddatacollectedbya question-naire,thereforemostofthedataiscross-sectional,exceptforthe behavioraldata(presence,useofappliancesandsystems)thatwas collectedbasedonaweeklycalendar.Inthiskindofmethodology, collectedcross-sectionaldataonbehaviorismodelledbytoolslike cluster(basedoncases)andfactoranalysis(basedonvariables). Inthisresearch,weworkedwithfactoranalysis.Furtherresearch couldcombinethesetwomethodologies,confirmingeachother’s results,aswellasprovidingmoreinsightintooccupantbehavior andelectricityconsumptionrelationship.
Intermsofthelimitationsofthisresearch,becauseourdatais collectedwithaquestionnaire,evenifthequestionsonpresence andbehavioraredetailedonaweeklybasis,respondentsmight havefilledintheinformationbasedonrememberingtheirhabits, butnot actualbehavior. Thiscouldbediscussed asalimitation ontheonehand,andasasuccessfulapproachontheotherhand [24–26].Secondly,ourdataiscollectedfromtwoVenex neighbor-hoods(satellitetowns)intheNetherlands,whereeducationand economicallevelsofhouseholdsarequitehomogenous.Evenifthe
representationofthesecharacteristicsinoursampleisinlinewith theDutchaverages,thehomogenousdistributionofthevariables bethereasonforthemtocomeupasnot-significantdeterminants ofoccupantbehavior.Thirdly,theinfluenceofHawthorneeffect [39]mustbementioned,wherethesurveyrespondents’ aware-nessofthegoalofthesurveymighthavedirectedthemtofill-in thequestionnairedifferentthanthereality.
6. Conclusionsandfuturework
Thisresearchaimedtoanalyzeindetailtheapplianceuseinthe Dutchhousingstock,anddefinebehavioralpatternsandprofilesof electricityconsumption.Weanalyzedsurveydatacollectedfrom 323dwellingsintheNetherlandsonapplianceownershipanduse; presence;cleaning;householdanddwellingcharacteristics.
First, a descriptive analysis was conducted onthe variables relatedtoownershipofappliances,theiruse,presence,and house-holdanddwellingcharacteristics,andelectricityconsumption.We created4groupswith‘ICE’,‘Cleaning’,‘Foodpreparation’and ‘Con-tinuouslyused’appliances.Asasecondstep,correlationanalysis wasconductedtoseetherelationshipbetweenvariablesrelated tooccupantbehaviorandelectricityconsumption.Theoutputsof thisanalysiswereusedtorealizeafactoranalysisrevealingthe underlyingfactorsofbehavior.Accordingly,wefoundtotal appli-anceuse,articulationoftechnology,presence,(personal)cleaning, andenergyconservationasthebehavioralfactorsofelectricity con-sumption.Afterwards,basedonthebehavioralfactors,wedefined thebehavioralpatterns(applianceuse,technology/presence, (per-sonal)cleaning/presence,energyconservation).Lastly,welooked for correlations betweenbehavioral factorsand household,and dwellingcharacteristics,fromwhichwefoundthebehavioral pro-files (family,techie, comforty, conscious). In the nextstep, we consideredtherelationshipbetweenbehavioralfactors,patterns, profilesandelectricityconsumption.Wefoundstatistically signif-icantcorrelationsbetweendifferentbehavioralpatterns,aswell asbetweendifferentbehavioral profilesinrelationtoelectricity consumption.
IntheNetherlands,relationshipsbetweenbehavioralpatterns, householdandbuildingcharacteristicsinrelationtoelectricity con-sumptionhave hardly beeninvestigated.Our workadds tothe researchbyusingactualbehaviordataaswellashouseholdand dwelling characteristics,and by drivingbehavioral factors, pat-terns,andprofiles,andlinkingthemtoeachotheraswellaslooking fortheirrelationshipwithelectricityconsumption.
Determining behavioral profiles could lead to more accu-rateprediction of electricity consumption in dwellings,as well as planning the targeted energy saving measures, and helping energycompaniesforbettercalculations.Consideringthat occu-pantbehaviormightbemorevisibleinthenewerdwellings,and thatbehaviormightberevealedmorepreciselybyanalyzing ‘elec-tricity’consumption,this researchmightprovide moredetailed andarticulatedinputonoccupantbehaviortoresearchandpolicy, which focusonmotivating/encouraging individuals’and house-holds’towardsmoreenergyefficientbehavior.
Intermsoffuturework,wecouldthinkofthefollowing direc-tions:
-Everyhouseholdowning1wirelessinternetrouterincontinuous useand6batterychargedappliancesshouldberesearched fur-therintermsofamobile24/7lifestyleandtheaddictiontobeing ‘connected’.
-Existingstudiesshowedthatlargepartofhouseholdenergyuse canbeexplainedthroughrepeateddailyroutines.Asfollowup work,thecausesofdailyroutinesofbehaviorthatarerelatedto electricityconsumptionshouldberesearchedfurther.
-Inrelationtothepointabove,collectingandanalyzing longitu-dinaldataonbehaviorisnecessarytoconfirmthefindingsfrom cross-sectionaldatatoovercomemethodologicallimitations. -Personalcleaningbehaviorappearedtobeanimportantfactor
bothinthepatternsandprofilesinthisresearch,whichsuggestsa comfortrelatedaspectofenergyconsumption.Thisaspectneeds tobeinvestigatedintermsofthemotivations,frequencies,and consequencesoftheparticularbehavior.
-Furtherresearchisalsoneededontheactualhouseholdappliance inventory,theirpowersandenergyratingsinmuchlarger sam-ples.Thisresearchcouldbeextendedbyspecificallyinvestigating theuseofICEappliances,foodpreparation(especiallyfreezer, dishwasher)and (personal)cleaning (useofshower andbath, useofdryerandwashingmachine)basedonspecificactivities likecooking,cleaning,orhobbies.Inaddition,thestand-byand on/offfunctionsandbatterychargedappliancesmustbestudied moreindetail.
Understandingtheoccupantbehaviorwillbeevenmore impor-tantinfutureforefficiencyofelectricityuse. Findingsfromthis research could help improving design of objects, systems and architecturaldesign inorder toreduce energy consumption by occupantsathome.
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