Electrification of Private Mobility: Driving Patterns, Multi-Car Households and Infrastructure
Doctoral thesis, 2019
Electrification of personal vehicles has the potential to significantly reduce carbon emissions. However, a large-scale transition to electric vehicles may be difficult as there are many individuals who collectively need to transition to this technology. Thus, it is important to understand car users needs, and to what extent a fully battery electric vehicle (BEV) fulfill these needs. In particular, batteries have been expensive and charging infrastructure scarce, thus creating a trade-off between the price of the car, and its driving range.
We use several GPS-measured driving data sets, interview data, and charging infrastructure data to analyse potential BEV adoption in multi-car households. Furthermore, we develop methods with regards to driving data modelling and analysis. We also estimate the size of a future charging infrastructure network.
We find that for short-range BEVs (120 km), a noteworthy adaptation is required for most users. However, within multi-car households, approximately 50% of the second cars need to adapt less than one day per month. We also assess how users in two-car households adapt to a BEV replacing one of their ordinary cars. We find large heterogeneity in how users adapt, where some increase the use of the BEV compared to the replaced car, and some decrease it. From interview data we find that most households have experienced no actual problems with the range limitation, but most would prefer a range of 200 km.
As a methodological contribution, we analyze the effect of modelling driving data with three probability distributions. Contrary to earlier literature we find that the Weibull and Log-Normal distributions overall fit driving data better than the Gamma distribution. But when estimating the frequency of long-distance driving we find that Weibull and Gamma perform better than Log-Normal. Finally, we have extended the traditional driving data analysis beyond distance analysis to destination analysis. One of the results is that BEVs drive a significantly larger share of their driving to their most common destinations compared to a conventional car.
We use several GPS-measured driving data sets, interview data, and charging infrastructure data to analyse potential BEV adoption in multi-car households. Furthermore, we develop methods with regards to driving data modelling and analysis. We also estimate the size of a future charging infrastructure network.
We find that for short-range BEVs (120 km), a noteworthy adaptation is required for most users. However, within multi-car households, approximately 50% of the second cars need to adapt less than one day per month. We also assess how users in two-car households adapt to a BEV replacing one of their ordinary cars. We find large heterogeneity in how users adapt, where some increase the use of the BEV compared to the replaced car, and some decrease it. From interview data we find that most households have experienced no actual problems with the range limitation, but most would prefer a range of 200 km.
As a methodological contribution, we analyze the effect of modelling driving data with three probability distributions. Contrary to earlier literature we find that the Weibull and Log-Normal distributions overall fit driving data better than the Gamma distribution. But when estimating the frequency of long-distance driving we find that Weibull and Gamma perform better than Log-Normal. Finally, we have extended the traditional driving data analysis beyond distance analysis to destination analysis. One of the results is that BEVs drive a significantly larger share of their driving to their most common destinations compared to a conventional car.
GPS-measured driving data
destination-based analysis
user-centered analysis
Battery electric vehicles
two-car households
KB-salen, Kemigården 4
Opponent: Assistant Professor Joakim Munkhammar, Department of Engineering Sciences, Uppsala University, Sweden
Author
Niklas Jakobsson
Chalmers, Space, Earth and Environment, Physical Resource Theory
Are multi-car households better suited for battery electric vehicles? - Driving patterns and economics in Sweden and Germany
Transportation Research, Part C: Emerging Technologies,;Vol. 65(2016)p. 1-15
Journal article
On the distribution of individual daily driving distances
Transportation Research Part B: Methodological,;Vol. 101(2017)p. 213-227
Journal article
Fast charging infrastructure for electric vehicles: Today's situation and future needs
Transportation Research Part D: Transport and Environment,;Vol. 62(2018)p. 314-329
Journal article
Jakobsson N., Karlsson S., Sprei F., How do users adapt to a battery electric vehicle in a two-car household?
Jakobsson N., Sprei F., Karlsson S., A destination-based analysis of electric, and conventional, cars in two-car households
Detta arbete har varit inriktat på att bedöma olika förutsättningar och potentialen för spridning av elbilar, speciellt sådana med ett relativt litet batteri och därmed med kortare räckvidd men också billigare. Analysen har baserats på flera dataset med kördata från olika länder, men framförallt har två dataset från Västsverige med både konventionella bilar och elbilar använts. Kördatan har varit uppmätt med GPS.
Analysen ger att under två månaders körning har ca 15% av de konventionella bilarna aldrig kört längre än den antagna räckvidden på 12 mil och ca 30% överskrider räckviddsbegränsningen högst en dag per månad. Vi visar också att elbilar med kort räckvidd passar särskilt bra som andrabil i flerbilshushåll. Bland sådana bilar kör ca 50% längre än räckvidden högst en dag per månad.
Vi har också låtit 25 st tvåbilshushåll pröva att ersätta en av sina vanliga konventionella bilar med en elbil (räckvidd ca 12 mil) under en tremånadersperiod. Av dessa hushåll har endast ett avstått från att göra en resa de annars skulle ha (eller eventuellt hade) gjort. Men intervjuer med hushållen visar att en majoritet av dessa ändå vill ha en längre räckvidd av trygghetsskäl. Det vanligaste önskemålet är ca 20 mils räckvidd för en elbil som andrabil, och mer än så för en förstabil eller för en ensam bil i ett hushåll. En möjlig tolkning av resultaten är att 12 mil är en lite för kort räckvidd för de vanligaste behoven, men att det också finns en stor grupp bilar som inte behöver ha särskilt mycket längre räckvidd än så.
Arbetet innefattar också en statistisk analys av hur kördata bör modelleras för att vara ett bra underlag för att bedöma möjligt utnyttjande av elbilar och laddhybrider, en estimering av laddinfrastrukturbehov och dessutom forskning kring hur en analys av olika slutdestinationer i GPS-uppmätt kördata kan öka förståelsen av elbilars användning.
Analysen ger att under två månaders körning har ca 15% av de konventionella bilarna aldrig kört längre än den antagna räckvidden på 12 mil och ca 30% överskrider räckviddsbegränsningen högst en dag per månad. Vi visar också att elbilar med kort räckvidd passar särskilt bra som andrabil i flerbilshushåll. Bland sådana bilar kör ca 50% längre än räckvidden högst en dag per månad.
Vi har också låtit 25 st tvåbilshushåll pröva att ersätta en av sina vanliga konventionella bilar med en elbil (räckvidd ca 12 mil) under en tremånadersperiod. Av dessa hushåll har endast ett avstått från att göra en resa de annars skulle ha (eller eventuellt hade) gjort. Men intervjuer med hushållen visar att en majoritet av dessa ändå vill ha en längre räckvidd av trygghetsskäl. Det vanligaste önskemålet är ca 20 mils räckvidd för en elbil som andrabil, och mer än så för en förstabil eller för en ensam bil i ett hushåll. En möjlig tolkning av resultaten är att 12 mil är en lite för kort räckvidd för de vanligaste behoven, men att det också finns en stor grupp bilar som inte behöver ha särskilt mycket längre räckvidd än så.
Arbetet innefattar också en statistisk analys av hur kördata bör modelleras för att vara ett bra underlag för att bedöma möjligt utnyttjande av elbilar och laddhybrider, en estimering av laddinfrastrukturbehov och dessutom forskning kring hur en analys av olika slutdestinationer i GPS-uppmätt kördata kan öka förståelsen av elbilars användning.
This work has focused on judging the potential for electric vehicle adoption, especially those with a relatively small battery, and thereby those that have a shorter driving range but also are cheaper. To do this, we have used GPS-measured driving data from several countries, but a special focus has been two sets of driving data from Western Sweden, containing both driving data for conventional cars, and for electric cars.
During two months of driving, we find that ca 15% of the conventional cars have never driven above the assumed range limitation of 120 km, while 30% drive above the range limitation at most once per month, which may be managed with access to public charging infrastructure. Short-range BEVs fit especially well as second cars in multi-car households, where 50% of these cars drive above the range limitation at most once per month.
We have also provided a small set (25) of two-car households with an electric car with ca 120 km of range, as a replacement for one of their ordinary cars for three months. During this period, one household chose to abstain from one trip they might otherwise have done due to the range limitation, while no other households had to abstain from a desired trip. The majority of the households did however still wish for a range of 200 km for a second car. They also thought they would need longer range than 200 km if an electric car would be their first car, or only car. A possible interpretation of the results is that 120 km range is a bit short for the most common needs. But also that there is a large group of cars that do not need a range that is very much larger than this.
The work also contain statistical analysis of how driving data should be analyzed, an estimation of the size of a future charging infrastructure network, and research on how a focus on destinations in driving data may contribute to understanding electric vehicle adoption.
During two months of driving, we find that ca 15% of the conventional cars have never driven above the assumed range limitation of 120 km, while 30% drive above the range limitation at most once per month, which may be managed with access to public charging infrastructure. Short-range BEVs fit especially well as second cars in multi-car households, where 50% of these cars drive above the range limitation at most once per month.
We have also provided a small set (25) of two-car households with an electric car with ca 120 km of range, as a replacement for one of their ordinary cars for three months. During this period, one household chose to abstain from one trip they might otherwise have done due to the range limitation, while no other households had to abstain from a desired trip. The majority of the households did however still wish for a range of 200 km for a second car. They also thought they would need longer range than 200 km if an electric car would be their first car, or only car. A possible interpretation of the results is that 120 km range is a bit short for the most common needs. But also that there is a large group of cars that do not need a range that is very much larger than this.
The work also contain statistical analysis of how driving data should be analyzed, an estimation of the size of a future charging infrastructure network, and research on how a focus on destinations in driving data may contribute to understanding electric vehicle adoption.
Measurement and analysis of vehicle movements among potential early adopters of electric vehicles
Swedish Energy Agency (35880-1), 2012-10-01 -- 2014-04-30.
An electric car in the two-car household – Use and adaptation
Swedish Energy Agency (35880-2), 2014-11-01 -- 2017-06-30.
Swedish Energy Agency (35880-2), 2014-11-01 -- 2016-12-31.
Driving Forces
Sustainable development
Areas of Advance
Transport
Energy
Subject Categories
Transport Systems and Logistics
Vehicle Engineering
Energy Systems
ISBN
978-91-7905-215-7
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4682
Publisher
Chalmers
KB-salen, Kemigården 4
Opponent: Assistant Professor Joakim Munkhammar, Department of Engineering Sciences, Uppsala University, Sweden