Bierlaire, Michel

Glerum, Aurélie

Thémans, Michaël

Infoscience - École polytechnique fédérale de Lausanne

INTEGRATING LATENT CONCEPTS IN A DEMAND MODELFOR ELECTRIC VEHICLESAurélie Glerum, TRANSP-OR, EPFLMichaël Thémans, TRACE, EPFLMichel Bierlaire, TRANSP-OR EPFLIFORS 2011Melbourne, 14th July 2011Outline● Introduction & motivation● Data collection● Methodology● Estimation results● Conclusion ● Further workIntroduction & motivationCurrent situation:● Search for ecological alternatives to fossil fuels:− Alternative fuel vehicles (LPG, CNG, etc.)− Electric vehicles (EV) being releasedCollaborative project EPFL-Renault:● Renault launches Zero Emission (Z.E.) product line in 2011-2012Introduction & motivationThe electric vehicle● No CO2 emissions● No noise● 185 km range● 8h to charge battery completely● Restricted charging locationsVariables that can influence people’s purchase choices.Introduction & motivationObjective of research project:● Analysis and prediction of demand for electric vehicles for private useResearch steps:1. Design of stated preference survey: hypothetical choicesituations− Classical vehicles (petrol, diesel, etc.)− Electric vehicles (from Renault Z.E. product line)2. Application of discrete choice methodology3. Forecasting of market sharesZoé Fluence Z.E.Introduction & motivationObjective of research project:● Analysis and prediction of demand for electric vehicles for private useResearch steps:1. Design of stated preference survey: hypothetical choicesituations− Classical vehicles (petrol, diesel, etc.)− Electric vehicles (from Renault Z.E. product line)2. Application of discrete choice methodology3. Forecasting of market sharesZoé Fluence Z.E.Focus of this talkIntroduction & motivationResearch issues raised:● Design of survey: choice situations close to reality● Modeling: develop discrete choice models to evaluate demand for EV:− Identification of target customers− Identification of ideal pricing of EV: i.e. analyze impact on choice of:● Vehicle price● Costs of usage● Battery lease● Potential governmental incentive− Assessment of the impact of attitudes and perceptions on choice● Forecasting: predict in realistic way the market shares of EV and classical vehicles among the target population of new buyers in● SwitzerlandData collection: type of surveyType of survey: stated preference (SP) survey● Within same car segment: hypothetical choices between− Own car− Renault – gasoline − Renault – electricPeugeot 207 Renault Clio Renault Zoé Renault ZoéRenault ClioData collection: sample5 types of respondents sampled in Switzerland:● Recent buyers● Prospective buyers● Renault customers● Pre-orders● NewsletterSampling protocol representativity from:● 3 language regions of Switzerland (German, French, Italian)● Gender● Age category (18-35 years, 36-55 years, 56-74 years)Data collection: sample5 types of respondents sampled in Switzerland:● Recent buyers● Prospective buyers● Renault customers● Pre-orders● NewsletterSampling protocol representativity from:● 3 language regions of Switzerland (German, French, Italian)● Gender● Age category (18-35 years, 36-55 years, 56-74 years)Sampling protocolAll available2 phases:● Phase I:− Characteristics of respondent’s car(s)− Socio-economic information− Mobility habits● Phase II:− Opinions on topics related to EV− Perceptions of four categories of EV− Choice situationsData collection: structure of surveyCreation of choice situationsData collection: structure of survey2 phases:● Phase I:− Characteristics of respondent’s car(s)− Socio-economic information− Mobility habits● Phase II:− Opinions on topics related to EV− Perceptions of four categories of EV− Choice situationsSegmentation, identification of potential usersData collection: structure of survey2 phases:● Phase I:− Characteristics of respondent’s car(s)− Socio-economic information− Mobility habits● Phase II:− Opinions on topics related to EV− Perceptions of four categories of EV− Choice situationsCharacterization of mobility of potential users:• Total distance performed on each weekday• Total distance performed in the weekend• Average duration of weekdaytrips• Number of cars in the household, etc.Data collection: structure of survey2 phases:● Phase I:− Characteristics of respondent’s car(s)− Socio-economic information− Mobility habits● Phase II:− Opinions on topics related to EV− Perceptions of four categories of EV− Choice situationsEvaluation of effect of attitudes on choice:• Environmental concern• Attitude towards new technologies• Perception of reliability of EV• Importance of design• Perception of leasingData collection: structure of survey2 phases:● Phase I:− Characteristics of respondent’s car(s)− Socio-economic information− Mobility habits● Phase II:− Opinions on topics related to EV− Perceptions of four categories of EV− Choice situationsEvaluation of effect of perceptions on choice:• Vehicles with combustion engine• Hybrid vehicles• Electric vehicles• Renault vehiclesData collection: structure of survey2 phases:● Phase I:− Characteristics of respondent’s car(s)− Socio-economic information− Mobility habits● Phase II:− Opinions on topics related to EV− Perceptions of four categories of EV− Choice situations • Core of SP survey• 5 choice experiments per individualData collection: structure of surveyAn example of choice experimentReported by respondentData collection: structure of surveyAn example of choice experimentDeduced from segment of owned carData collection: structure of surveyAn example of choice experimentObtained from data base of cars currently sold on marketData collection: structure of surveyAn example of choice experimentFixed attributesData collection: structure of surveyAn example of choice experimentDesign variablesData collection: structure of surveyDesign variablesEV variable Level 1 Level 2 Level 3 Level 4Purchase price (Pown + 5’000) * 0.8 (Pown+ 5’000) * 1 (Pown + 5’000) * 1.2 -Governmentalincentive- 0 CHF - 500 CHF - 1’000 CHF - 5’000 CHFCost of fuel/electricityfor 100 km1.70 CHF 3.55 CHF 5.40 CHF -Battery lease 85 CHF 105 CHF 125 CHF -Methodology: experimental designExperimental design:● Fractional factorial design● Four-factor interactions confounded             resolution V● Blocking with respect to 4 target groups:1. Recent buyers2. Prospective buyers3. Renault customers4. Pre-ordersNewsletterMethodology: experimental designSampling procedure:1. Selection of sequences of levels relative to respondent’s sample group2. Sampling with replacementbetween individuals3. Sampling without replacement for choice situations of each individualSampling weights: ● Correct for oversampling of some levels● Weights computed with iterative proportional fitting (IPF)Incentive Price Fuel cost of 100 km Battery lease1 0 0.80 1.70 852 0 1.00 3.55 1253 0 1.00 5.40 1054 0 1.20 3.55 1055 -500 0.80 1.70 1256 -500 1.00 3.55 857 -500 1.00 5.40 1058 -500 1.20 3.55 1059 -1000 0.80 3.55 10510 -1000 1.00 5.40 10511 -1000 1.00 3.55 8512 -1000 1.20 1.70 12513 -5000 0.80 3.55 10514 -5000 1.00 5.40 10515 -5000 1.00 3.55 12516 -5000 1.20 1.70 85Methodology: discrete choice model● Achieve modeling and forecasting goals use of discrete choice methodology● Logit model with multiple alternativesUtilities Socio-economiccharacteristicsVehicle characteristics(e.g. price)EV characteristics(e.g. battery lease)Revealed car choiceSample group(e.g. recent buyers)Methodology: discrete choice model● Achieve modeling and forecasting goals use of discrete choice methodology● Logit model with multiple alternativesSignificantly different behaviors acrosssample groups 5 sample groups rearranged into 3 groups A, B, CUtilities Socio-economiccharacteristicsVehicle characteristics(e.g. price)EV characteristics(e.g. battery lease)Revealed car choiceSample group(e.g. recent buyers)Estimation results 1Gasoline – competitors(GC)Gasoline – Renault (GR)Electric – Renault (EV)Estimate t-test Estimate t-test Estimate t-testASC GASOLINE COMPETITORS -1.16 -2.94ASC GASOLINE RENAULT -1.39 -3.57PRICE GASOLINE COMPETITORS -0.0225 -1.31PRICE GASOLINE RENAULT A,C -0.225 -4.03PRICE GASOLINE RENAULT B -0.645 -4.57PRICE ELECTRIC RENAULT A -0.347 -5.63PRICE ELECTRIC RENAULT B -0.922 -6.24PRICE ELECTRIC RENAULT C -0.545 -7.66COST OF REFUELING (SMALL CONSUMPTION) -0.0384 -1.57 -0.0384 -1.57COST OF RECHARGING BATTERY (HIGH) -0.424 -3.69COST OF RECHARGING BATTERY (MEDIUM) -0.13 -1.18BATTERY LEASE (HIGH) -0.206 -1.79BATTERY LEASE (MEDIUM) -0.0626 -0.58INCENTIVE (HIGH) 0.721 5.73INCENTIVE (MEDIUM) 0.0803 0.61INCENTIVE (LOW) 0.0179 0.14Estimation results 1Gasoline – competitors(GC)Gasoline – Renault (GR)Electric – Renault (EV)Estimate t-test Estimate t-test Estimate t-testASC GASOLINE COMPETITORS -1.16 -2.94ASC GASOLINE RENAULT -1.39 -3.57PRICE GASOLINE COMPETITORS -0.0225 -1.31PRICE GASOLINE RENAULT A,C -0.225 -4.03PRICE GASOLINE RENAULT B -0.645 -4.57PRICE ELECTRIC RENAULT A -0.347 -5.63PRICE ELECTRIC RENAULT B -0.922 -6.24PRICE ELECTRIC RENAULT C -0.545 -7.66COST OF REFUELING (SMALL CONSUMPTION) -0.0384 -1.57 -0.0384 -1.57COST OF RECHARGING BATTERY (HIGH) -0.424 -3.69COST OF RECHARGING BATTERY (MEDIUM) -0.13 -1.18BATTERY LEASE (HIGH) -0.206 -1.79BATTERY LEASE (MEDIUM) -0.0626 -0.58INCENTIVE (HIGH) 0.721 5.73INCENTIVE (MEDIUM) 0.0803 0.61INCENTIVE (LOW) 0.0179 0.14Price affects negatively utility of 3 vehicles.Average impact 1) highest for EV2) second highest for GR 3) lowest for GCEstimation results 1Price affects negatively utility of 3 vehicles.Average impact 1) highest for EV2) second highest for GR 3) lowest for GCEffect of price of GR and EV more important for group B.Gasoline – competitors(GC)Gasoline – Renault (GR)Electric – Renault (EV)Estimate t-test Estimate t-test Estimate t-testASC GASOLINE COMPETITORS -1.16 -2.94ASC GASOLINE RENAULT -1.39 -3.57PRICE GASOLINE COMPETITORS -0.0225 -1.31PRICE GASOLINE RENAULT A,C -0.225 -4.03PRICE GASOLINE RENAULT B -0.645 -4.57PRICE ELECTRIC RENAULT A -0.347 -5.63PRICE ELECTRIC RENAULT B -0.922 -6.24PRICE ELECTRIC RENAULT C -0.545 -7.66COST OF REFUELING (SMALL CONSUMPTION) -0.0384 -1.57 -0.0384 -1.57COST OF RECHARGING BATTERY (HIGH) -0.424 -3.69COST OF RECHARGING BATTERY (MEDIUM) -0.13 -1.18BATTERY LEASE (HIGH) -0.206 -1.79BATTERY LEASE (MEDIUM) -0.0626 -0.58INCENTIVE (HIGH) 0.721 5.73INCENTIVE (MEDIUM) 0.0803 0.61INCENTIVE (LOW) 0.0179 0.14Estimation results 1Price affects negatively utility of 3 vehicles.Average impact 1) highest for EV2) second highest for GR 3) lowest for GCEffect of price of GR and EV more important for group B.Effect of price of EV least important for groups C.Gasoline – competitors(GC)Gasoline – Renault (GR)Electric – Renault (EV)Estimate t-test Estimate t-test Estimate t-testASC GASOLINE COMPETITORS -1.16 -2.94ASC GASOLINE RENAULT -1.39 -3.57PRICE GASOLINE COMPETITORS -0.0225 -1.31PRICE GASOLINE RENAULT A,C -0.225 -4.03PRICE GASOLINE RENAULT B -0.645 -4.57PRICE ELECTRIC RENAULT A -0.347 -5.63PRICE ELECTRIC RENAULT B -0.922 -6.24PRICE ELECTRIC RENAULT C -0.545 -7.66COST OF REFUELING (SMALL CONSUMPTION) -0.0384 -1.57 -0.0384 -1.57COST OF RECHARGING BATTERY (HIGH) -0.424 -3.69COST OF RECHARGING BATTERY (MEDIUM) -0.13 -1.18BATTERY LEASE (HIGH) -0.206 -1.79BATTERY LEASE (MEDIUM) -0.0626 -0.58INCENTIVE (HIGH) 0.721 5.73INCENTIVE (MEDIUM) 0.0803 0.61INCENTIVE (LOW) 0.0179 0.14Estimation results 1Cost of refueling: negative effect on choice of gasoline cars with use cost < 15 CHF / 100 kmGasoline – competitors(GC)Gasoline – Renault (GR)Electric – Renault (EV)Estimate t-test Estimate t-test Estimate t-testASC GASOLINE COMPETITORS -1.16 -2.94ASC GASOLINE RENAULT -1.39 -3.57PRICE GASOLINE COMPETITORS -0.0225 -1.31PRICE GASOLINE RENAULT A,C -0.225 -4.03PRICE GASOLINE RENAULT B -0.645 -4.57PRICE ELECTRIC RENAULT A -0.347 -5.63PRICE ELECTRIC RENAULT B -0.922 -6.24PRICE ELECTRIC RENAULT C -0.545 -7.66COST OF REFUELING (SMALL CONSUMPTION) -0.0384 -1.57 -0.0384 -1.57COST OF RECHARGING BATTERY (HIGH) -0.424 -3.69COST OF RECHARGING BATTERY (MEDIUM) -0.13 -1.18BATTERY LEASE (HIGH) -0.206 -1.79BATTERY LEASE (MEDIUM) -0.0626 -0.58INCENTIVE (HIGH) 0.721 5.73INCENTIVE (MEDIUM) 0.0803 0.61INCENTIVE (LOW) 0.0179 0.14Estimation results 1Design variables:1) Negative effect of  high charging costs (5.40 CHF)2) Negative effect of high battery lease (125 CHF)3) Positive effect of high incentive (5’000 CHF)Gasoline – competitors(GC)Gasoline – Renault (GR)Electric – Renault (EV)Estimate t-test Estimate t-test Estimate t-testASC GASOLINE COMPETITORS -1.16 -2.94ASC GASOLINE RENAULT -1.39 -3.57PRICE GASOLINE COMPETITORS -0.0225 -1.31PRICE GASOLINE RENAULT A,C -0.225 -4.03PRICE GASOLINE RENAULT B -0.645 -4.57PRICE ELECTRIC RENAULT A -0.347 -5.63PRICE ELECTRIC RENAULT B -0.922 -6.24PRICE ELECTRIC RENAULT C -0.545 -7.66COST OF REFUELING (SMALL CONSUMPTION) -0.0384 -1.57 -0.0384 -1.57COST OF RECHARGING BATTERY (HIGH) -0.424 -3.69COST OF RECHARGING BATTERY (MEDIUM) -0.13 -1.18BATTERY LEASE (HIGH) -0.206 -1.79BATTERY LEASE (MEDIUM) -0.0626 -0.58INCENTIVE (HIGH) 0.721 5.73INCENTIVE (MEDIUM) 0.0803 0.61INCENTIVE (LOW) 0.0179 0.14Estimation results 2Gasoline – competitors(GC)Gasoline – Renault (GR)Electric – Renault (EV)Estimate t-test Estimate t-test Estimate t-testSAMPLE GROUP A COMP. 1.89 5.18SAMPLE GROUP B COMP. -1.24 -1.67SAMPLE GROUP A REN. 0.922 2.57SAMPLE GROUP B REN. 2.31 4.59USE PT GAS. A,C COMP. -0.389 -3.03USE PT GAS. B COMP. -1.59 -2.28USE PT GAS. REN. -0.682 -5.44FAMILY STATUS GAS. COMP. -0.242 -2.15FAMILY STATUS GAS. REN. 0.0523 0.5INCOME GAS. COMP. -0.273 -2.41INCOME GAS. REN. -0.279 -2.66CARS HOUSEHOLD GAS. COMP. -0.166 -2.26CARS HOUSEHOLD GAS. A,C REN. -0.161 -2.21CARS HOUSEHOLD GAS. B REN. -0.668 -5.56Estimation results 2Socio-economic characteristics have meaningful interpretation.Related to:Sample group• Usage of public transport• Family status• Income• Cars in the household••Differences across sample groups capturedGasoline – competitors(GC)Gasoline – Renault (GR)Electric – Renault (EV)Estimate t-test Estimate t-test Estimate t-testSAMPLE GROUP A COMP. 1.89 5.18SAMPLE GROUP B COMP. -1.24 -1.67SAMPLE GROUP A REN. 0.922 2.57SAMPLE GROUP B REN. 2.31 4.59USE PT GAS. A,C COMP. -0.389 -3.03USE PT GAS. B COMP. -1.59 -2.28USE PT GAS. REN. -0.682 -5.44FAMILY STATUS GAS. COMP. -0.242 -2.15FAMILY STATUS GAS. REN. 0.0523 0.5INCOME GAS. COMP. -0.273 -2.41INCOME GAS. REN. -0.279 -2.66CARS HOUSEHOLD GAS. COMP. -0.166 -2.26CARS HOUSEHOLD GAS. A,C REN. -0.161 -2.21CARS HOUSEHOLD GAS. B REN. -0.668 -5.56ConclusionModel demand for electric vehicles:Survey:• Realistic choice context: adapted to respondentModel:• Estimation results with meaningful interpretation• Assess impact of price characteristics• Identify target customersFurther work: modelingImprove specification:Capture effect on choice of unobserved variables (attitudes, perceptions)Utilities Socio-economiccharacteristicsVehicle characteristics(e.g. price)EV characteristics(e.g. battery lease)Revealed car choiceSample group(e.g. recent buyers)Further work: modelingImprove specification:Capture effect on choice of unobserved variables (attitudes, perceptions)Utilities Socio-economiccharacteristicsVehicle characteristics(e.g. price)EV characteristics(e.g. battery lease)Revealed car choiceIndicators of opinionsIntegrated choice and latent variable model (Walker, 2001)Sample group(e.g. recent buyers)Attitudes/perceptions (e.g. EV as ecological)Further work: forecastingModel estimates obtain market sharesCorrection of market shares needed make themrealistic by correcting them with market data:● Correction of ASC relative to gasoline alternatives:− Socio-demographic characteristics (age, gender, language)− Sample group (recent & prospective buyers, Renault customers, pre-orders, newsletter)● Correction for missing alternative ‘gasoline-competitors’ for owners of a Renault car● Correction for missing alternative ‘None of the cars’Thanks!

Integrating latent concepts in a demand model for electric vehicles

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Integrating latent concepts in a demand model for electric vehicles

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