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Electric vehicles in action
KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.ORCID iD: 0000-0002-1691-091X
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis analyses the political and practical conditions for introducing electric vehicles in Swedish public authorites and discusses the potential for using electric vehicles in public transport and public fleets. The work has been carried out using an interdisciplinary research approach. Such an approach brings new insights to energy studies; the combination of technical methods and methods from social science allows the technology to be studied in its societal context.

Local self-government enables Swedish public authorities to implement local solutions in order to achieve national policy goals. However, the results show that for energy and transport policy a clear allocation of responsibilities between local and regional levels is lacking – and this clarity is also lacking between the different policy areas. The lack of policy integration implies a risk that local policy development can miss the mark when it comes to the overall policy goal. Furthermore, findings show that so-called policy entrepreneurs can succeed in putting electric vehicles on the political agenda, and they can enforce decisions and deploy the vehicles within the public bodies.

The usage of plug-in electric vehicles in public fleets has been studied using (among other sources) logbooks, interviews, questionnaires and focus groups. Findings demonstrate a great potential to introduce plug-in electric vehicles through fleets. Although the usage varied slightly during the year, and winter conditions implied a general reduction in use, the results show that the deployment strategy is a central factor for the extent of the vehicle usage. Vehicles that are assigned a certain user or a specific task show a high degree of utilisation. Even though plug-in electric vehicles available through car-pools have a large potential group of users, the options also implies that users can instead choose a conventional vehicle. However, interventions to increase usage have proven to be successful. Policy entrepreneurial actions attract new users and revising organisational regulations, i.e. vehicle or environmental policies, shapes new behaviours. In this study, fleet vehicle users have proven to be relative indifferent to which fuel or technology they use, but acceptance for operation failure is very low.

Based on a demonstration project of series hybrid buses in regular service, the possibility of increased electrification of public transport is discussed. The contribution of hybridisation is analysed through assessment of different types of driving conditions. Results show that significant improvements in energy efficiency can be achieved but, because actual and optimal driving conditions differ, there is a risk of overestimating the contribution.

Sweden has set very ambitious national targets for its road transport system, i.e. to be fossil-fuel independent by 2030, and electrification is an important measure in reaching this goal. Given the magnitude of the challenge, it is not only the responsible thing to do; findings also show several advantages of introducing electric vehicles in the public sector first. 

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. , x, 71 p.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2015:50
Keyword [en]
electric vehicles, interdisciplinary approach, public fleets, public transport
National Category
Chemical Engineering
Identifiers
URN: urn:nbn:se:kth:diva-173647ISBN: 978-91-7595-689-3 (print)OAI: oai:DiVA.org:kth-173647DiVA: diva2:854203
Public defence
2015-10-09, Kollegiesalen, Brinellvägen 8, KTH, Stockholm, 13:30 (English)
Opponent
Supervisors
Funder
Swedish Energy Agency
Note

QC 20150916

Available from: 2015-09-16 Created: 2015-09-16 Last updated: 2015-09-16Bibliographically approved
List of papers
1. Bridging the implementation gap: Combining backcasting and policy analysis to study renewable energy in urban road transport
Open this publication in new window or tab >>Bridging the implementation gap: Combining backcasting and policy analysis to study renewable energy in urban road transport
2015 (English)In: Transport Policy, ISSN 0967-070X, E-ISSN 1879-310X, Vol. 37, 72-82 p.Article in journal (Refereed) Published
Abstract [en]

This paper combines backcasting and policy analysis to identify the opportunities for and barriers to the increased use of renewable energy and energy-effcient vehicles in an urban road transport system, namely, that of Stockholm, Sweden, in 2030. The combination of methods could bridge the implementation gap between scenario-based research and actual policy implementation and thus increase the chances of research being implemented in practise. In the case study, backcasting identifies a need for diverse fuels and vehicles and for immediate policy action. However, analysis of policy integration demonstrates that such action is unlikely given current policy structures. The fundamental lack of integration between energy and transport policy obstructs measures to increase the use of renewable fuels and more energy-effcient vehicles, which in turn obstructs the reduction of CO2 emissions from transport. The combination of backcasting and policy analysis is demonstrated to improve our under- standing of the prerequisites for transitioning to a system based on renewable energy, and could thus be useful in further research.

Keyword
Energy efficiency, Energy policy, Renewable fuels, Scenario studies, Transport policy, Urban road transport
National Category
Public Administration Studies Energy Engineering
Identifiers
urn:nbn:se:kth:diva-159892 (URN)10.1016/j.tranpol.2014.10.014 (DOI)000347594100008 ()2-s2.0-84910670413 (Scopus ID)
Funder
Swedish Energy Agency
Note

QC 20150225

Available from: 2015-02-11 Created: 2015-02-11 Last updated: 2017-12-04Bibliographically approved
2. First experiences of ethanol hybrid buses operating in public transport
Open this publication in new window or tab >>First experiences of ethanol hybrid buses operating in public transport
2011 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

With the ambitions to further increase its share of renewable fuels and to reduce the amount of local carbon dioxide emissions and noise, Stockholm Public Transport (SL), together with bus manufacturer Scania and bus operator Nobina, hosted a one year project to evaluate the performance of ethanol hybrid buses. Six ethanol hybrid buses were operating in regular public transport between June 2009 and June 2010. During this period the buses were operating at three different suburban routes. The purpose was to accumulate experimental data and to validate the robustness of the ethanol hybrid system and its components. In addition, in order to obtain comparable data, standardized duty cycle tests were performed. Furthermore, with the objective to assemble experimental data during heavy traffic and low mean velocity conditions, two urban routes were selected for staged tests with one ethanol hybrid bus.

The purpose of this paper is to evaluate the energy efficiency of the electrified driveline and hybrid components of the Scania ethanol hybrid bus based on experimental data.

The bus is a series hybrid vehicle with regenerative braking. A start/stop software to avoid idling was optional. The key components of a series hybrid are internal combustion engine, generator, energy storage, electric engine and resistor. The energy storage was commercially available super capacitors. The components of the electric powertrain were developed and delivered by Voith Turbo. A bus with identical exterior properties, an ethanol internal combustion engine coupled to a conventional automatic gearbox but without a hybrid system was used as a reference throughout the project. The measurement equipment was installed in the hybrid system to capture energy flows in and out of key components. Parallel logging of GPS coordinates generated a velocity profile which coupled with energy flow data constitute to the foundation of the analysis.

The main results are presented as Sankey diagrams visualizing the energy flow through the electrified powertrain and determines the energy efficiency for each of the different traffic situations. The initial experimental results indicate that the reduction of fuel consumption benefits from routes with low mean velocity and a high number of stop. At such favorable conditions the fuel reduction are in the order of 30 %. The potential additional fuel savings of the start/stop software has been simulated and adds another 5-10 % fuel reduction. Not all of the hybrid system’s components are not yet robust enough and need further development. The super capacitors work consistent and are suitable as energy storage for this application. 

Keyword
Ethanol hybrid bus, Series hybrid, Duty cycle, Urban public transportation
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-107424 (URN)
Conference
World Renewable Energy Congress, May 8-13 2011, Linköping, Sweden
Note

QC 20130527

Available from: 2012-12-11 Created: 2012-12-11 Last updated: 2015-09-16Bibliographically approved
3. Analysis of the fuel economy improvement potential of ethanol hybrid buses
Open this publication in new window or tab >>Analysis of the fuel economy improvement potential of ethanol hybrid buses
2011 (English)In: Proceedings of the 24th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2011, Nis University , 2011, 2220-2229 p.Conference paper, Published paper (Refereed)
Abstract [en]

With the ambitions to further increase its share of renewable fuels and to reduce the amount of carbon dioxide emissions, local emissions and noise, Stockholm Public Transport (SL) hosted a one-year project to evaluate the performance of ethanol hybrid buses. An important part of the project was the duty cycle tests according to SORT - Standardised On-Road Tests cycles (developed by the International Association of Public Transport, UITP). The duty cycle tests generated experimental data, on which this paper’s discussion is based upon. The purpose of this article is to evaluate the potential of energy-efficiency improving measures on the powertrain. The ethanol hybrid bus is a series hybrid vehicle with regenerative braking. A start/stop software to avoid idling was optional. A bus with similar exterior properties, but with the ethanol internal combustion engine coupled to a conventional automatic gearbox instead of a hybrid powertrain was used as a reference throughout the project. Based on both experimental data and simulations, several measures to increase the overall energy-efficiency may be proposed. Assessed measures to increase the energy-efficiency include size optimization of powertrain components, such as energy storage and electric motor, and internal combustion engine (identified by using Sankey diagrams), adjustment of the super capacitors energy management system and utilisation of engine start/stop functionality. Analysis shows that the size of the energy storage is well attuned if applied as urban transport. It would be possible to downsize the ICE, from approximately 200 kW to approximately 150 kW, without losing substantial performance. Using the start/stop software reduces the fuel consumption with 15 % in the standardized city duty cycle but has the potential for even further fuel economy improvements in real traffic with more idling.

Place, publisher, year, edition, pages
Nis University, 2011
Keyword
Ethanol hybrid bus, Series hybrid, Energy efficiency, Energy flow analysis, Sankey diagrams
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-107440 (URN)2-s2.0-84903642241 (Scopus ID)978-866055016-5 (ISBN)
Conference
The 24th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, July 4-7 2011, Novi Sad, Serbia
Note

QC 20130604

Available from: 2012-12-11 Created: 2012-12-11 Last updated: 2015-09-16Bibliographically approved
4. Socio-technical experiences from electric vehicle utilisation in commercial fleets
Open this publication in new window or tab >>Socio-technical experiences from electric vehicle utilisation in commercial fleets
2014 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 123, 82-93 p.Article in journal (Refereed) Published
Abstract [en]

Commercial vehicle fleets are in many ways an attractive entry for electric vehicles into the transport system. In total, 174 electric vehicles have operated in commercial vehicle fleets and gathered socio-technical data over a period of 18 months, resulting in 302,000 all electric kilometres. This paper presents two perspectives regarding electric vehicle operations in commercial vehicle fleets - the functionality perspective, illustrated by the vehicle actions, and the user perspective that addresses the implementation of the task. The socio-technical analysis has resulted in four major findings. With time, the overall usage and the driving distance between charging occasions increase. It is not the passage of time that has influenced this behaviour but it may be explained as the result of accumulated experience. Swedish winter conditions show regression in usage, foremost due to users not familiar with the range reduction caused by the heating system. The need for public charging has been shown to be modest, which in an introductory phase with limited development of charging infrastructure, makes commercial vehicle fleets favourable to electrify over private vehicle fleets. According to deployment strategy, the different user groups' ability to incorporate the electric vehicles in their daily activities has been explored and this paper shows large potential for substituting traditional internal combustion engine vehicles within commercial vehicle fleets. Electric vehicles have been made available through a technology procurement scheme and have generated both kilometres and experience, which has come to increase the understanding of the usage of electric vehicles in commercial vehicle fleets.

Keyword
Battery electric vehicles, Plug-in hybrid electric vehicles, Socio-technical approach, Technology procurement
National Category
Other Chemical Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-145250 (URN)10.1016/j.apenergy.2014.02.051 (DOI)000336017400010 ()2-s2.0-84896034694 (Scopus ID)
Funder
Swedish Energy Agency
Note

QC 20140612

Available from: 2014-05-14 Created: 2014-05-14 Last updated: 2017-12-05Bibliographically approved
5. Investigating barriers for electric vehicle deployment in commercial fleets
Open this publication in new window or tab >>Investigating barriers for electric vehicle deployment in commercial fleets
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Commercial vehicle fleets constitute for several reasons a favorable entry for plug-in electric vehicles (PEVs) into the road transport system. During an extensive demonstration project, with 500 PEVs operating in 100 public and private enterprises, 40 battery electric vehicle (BEV) users were invited to focus group discussions. The focus groups allowed the users to discuss their actual experiences of operating BEVs and thereby provide a greater understanding of the operating conditions experienced by BEV users in different organisations. The findings complemented earlier data collected from the demonstration project and further explained the recorded driving and charging behaviour. The conditions to adopt the BEVs vary between the organisations. Given favourable conditions, users adopt and accept the technology. A uncommitted introduction implies an iterated learning process, which effect acceptance and users may deviate. Based on the discussions, this paper identifies organisational barriers, rather than traditional technical or economical barriers, which is of interest since they ultimately determine overall usage and influence user acceptance. The organisational barriers can be addressed by certain assistive measures to ensure an uptake and deployment. The paper contributes with new findings regarding implementation of BEVs in commercial vehicle fleets and provides an in- depth understanding of the operational barriers that public or private enterprises face when introducing BEVs in their vehicle fleets. 

National Category
Public Administration Studies Energy Engineering
Identifiers
urn:nbn:se:kth:diva-173641 (URN)
Note

QS 2015

Available from: 2015-09-16 Created: 2015-09-16 Last updated: 2015-09-16Bibliographically approved
6. An end has a start – investigating the usage of electric vehicles in commercial fleets
Open this publication in new window or tab >>An end has a start – investigating the usage of electric vehicles in commercial fleets
2015 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, 1932-1937 p.Article in journal (Refereed) Published
Abstract [en]

The road transport system is moving, slowly but surely, away from using fossil fuels. Plug-in electric vehicles (PEVs) are an energy-efficient alternative to conventional vehicles. Commercial vehicle fleets are an attractive entry for PEVa into the transport system. This paper presents findings from a three-year study of 550 PEVs and their users. A combination of technical and social science methods provides a basis for greater understanding of PEV operations in commercial vehicle fleets. This paper shows that battery electric vehicles (BEVs) have proven their functionality in several applications, but that winter conditions still imply an unjustified decrease in use. Usage varies according to application but results show that in general a substantial share of the battery capacity is redundant. Findings indicate that usage is not necessarily inhibited by the technical specifications of the battery but by the operational conditions in which commercial duties are performed. The only reliable alternative is to return with a large battery surplus. The vehicles studied have demonstrated their functionality and the users are positive. Plug-in hybrid electric vehicles (PHEV) imply no restrictions in mobility, which results in high user satisfaction. Commercial vehicle fleets are suitable for PEV operations and with growing acceptance users have requested more PEVs hence a significant possibility exists to substitute a large share of the fossil-fuelled vehicles operating in commercial vehicle fleets. 

National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-173646 (URN)10.1016/j.egypro.2015.07.223 (DOI)2-s2.0-84947125512 (Scopus ID)
Conference
The 7th International Conference on Applied Energy (ICAE2015)
Note

QC 20150916

Available from: 2015-09-16 Created: 2015-09-16 Last updated: 2017-12-04Bibliographically approved
7. Introducing plug-in electric vehicles in public authorities
Open this publication in new window or tab >>Introducing plug-in electric vehicles in public authorities
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Plug-in electric vehicles have the potential to contribute to a more energy-efficient and a less fossil dependent road transport system. Swedish local authorities are obligated through legislation to substitute fossil-fuelled vehicles and plug-in electric vehicles offer an alternative for achieving their climate goals. Previous studies assign certain individuals – the policy entrepreneurs – a central role when implementing new technologies in public authorities. By combining the theoretical model of policy entrepreneurs with the theory of outcome indicators, this paper demonstrates how the policy entrepreneur affects and accelerates the introduction of plug-in electric vehicles in local public authorities. The result shows that policy entrepreneurs undertake actions to inform and persuade the decision-makers and raise the issue on the political agenda. The policy entrepreneurs assess the travel demand, find appropriate applications and supervise the deployment process. The policy entrepreneurs inform and inspire vehicle users as a way to ensure acceptance and to increase usage. There are examples of policy entrepreneurs that have accomplished changes in policies governing vehicle use to favour the plug-in electric vehicles. Practical experiences legitimate the policy entrepreneurs when involving local society. The policy entrepreneurs consolidate the new technology within policy documents, among the users and in the surrounding society. 

National Category
Energy Engineering Public Administration Studies
Identifiers
urn:nbn:se:kth:diva-173645 (URN)
Note

QS 2015

Available from: 2015-09-16 Created: 2015-09-16 Last updated: 2015-09-16Bibliographically approved

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