IN THE FIELD OF TECHNOLOGY DEGREE PROJECT
VEHICLE ENGINEERING
AND THE MAIN FIELD OF STUDY INDUSTRIAL MANAGEMENT, SECOND CYCLE, 30 CREDITS
,
STOCKHOLM SWEDEN 2020
An Economic Analysis of
Electric Road System
Technology
An Electrification of Södertörn Crosslink
OSCAR NILSMO
ERIC WRANNE
IN THE FIELD OF TECHNOLOGY DEGREE PROJECT
MECHANICAL ENGINEERING AND THE MAIN FIELD OF STUDY INDUSTRIAL MANAGEMENT, SECOND CYCLE, 30 CREDITS
,
STOCKHOLM SWEDEN 2020
An Economic Analysis of
Electric Road System
Technology
An Electrification of Södertörn Crosslink
OSCAR NILSMO
ERIC WRANNE
An Economic Analysis of Electric Road System
Technology
An Electrification of Södertörn Crosslink
by
Oscar Nilsmo
Eric Wranne
Master of Science Thesis TRITA-ITM-EX 2020:204 KTH Industrial Engineering and Management
Ekonomisk analys av elvägssystemteknik
Elektrifiering av Tvärförbindelse Södertörn
Oscar Nilsmo
Eric Wranne
Examensarbete TRITA-ITM-EX 2020:204 KTH Industriell teknik och management
Master of Science Thesis TRITA-ITM-EX 2020:204
An Economic Analysis of Electric Road
System Technology
An Electrification of Södertörn Crosslink
Oscar Nilsmo Eric Wranne Approved 2020-09-24 Examiner Bo Karlsson Supervisor Lars Uppvall Commissioner SWECO Contact person Thomas Sjöström Abstract
The following paper is a master thesis written at KTH Royal Institute of Technology in Stockholm, Sweden. This master thesis is done in a collaboration with a Swedish Consulting Company SWECO. The main focus of this master thesis is to investigate if an implementation of Electric Road System (ERS) on Södertörn Crosslink is profitable, and if so, approximate the payback period for the investment. Additionally, the costs associated with the electrification of the bus fleet, currently operating on road 259, will be determined. There are three different ERS technologies, inductive (wireless), conductive overhead, and conductive rail have been compared, looking at advantages and disadvantages, with regard to the implementation of ERS on Södertörn Crosslink. To accompany this, case study methods have been used, where the results are based on interviews, theory and calculations. The result shows that the payback period for both inductive and conductive rail, based on this study’s forecast, is 7 years and 9,3 years respectively with regard to a discount factor of 9,0 percent. However, the conductive overhead solution does not seem to be profitable as this technology is limited to heavy trucks and buses capable of connecting to the overhead wires. The inductive ERS solution seems to be the best suitable option for Södertörn Crosslink, viewed from an economical and technological perspective. while also considering other factors such as aesthetics.
Key-words: Electric Road System, Electric Road Operator, Södertörn Crosslink,
Examensarbete TRITA-ITM-EX 2020:204
Ekonomisk analys av elvägssystemteknik
Elektrifiering av framtida Tvärförbindelse SödertörnOscar Nilsmo Eric Wranne Godkänt 2020-09-24 Examinator Bo Karlsson Handledare Lars Uppvall Uppdragsgivare SWECO Kontaktperson Thomas Sjöström Sammanfattning
Denna rapport är ett examensarbete skrivet på KTH, Kungliga Tekniska Högskolan, i Stockholm, Sverige. Denna masteruppsats gjordes i samarbete med ett svenskt konsultföretag, SWECO. Det huvudsakliga syftet av denna masteruppsats är att ta reda på vilka möjligheter det finns för en elektrifiering av framtida motorvägen Tvärförbindelse Södertörn i södra Stockholm, Sverige. Syftet med masteruppsatsen är att undersöka om det finns lönsamhet i implementeringen av ett elvägssystem på Tvärförbindelse Södertörn och därefter approximera hur lång den eventuella återbetalningstiden skulle vara. Kostnader för en elektrifiering av bussflottan, som kör för närvarande på väg 259, ska också bestämmas. Tre olika tekniker för elvägssystem, induktiv (trådlös), konduktiv via luftledningar, och konduktiv via spår, jämförs med avseende på deras för och nackdelar, för att därefter kunna bestämma den mest lämpliga lösningen för Tvärförbindelse Södertörn. För att jämföra dessa tekniker har en fallstudie genomfört. Resultatet visade att återbetalningstiden för de induktiva och konduktiva (via spår) lösningarna, utifrån egen prognos, är 7 år respektive 9,3 år, med hänsyn till diskonteringsränta på 9,0 procent. Den konduktiva lösningen (via luftledningar) visade sig dock inte lönsam i och med att denna teknik är begränsad då endast högre fordon, lastbilar eller bussar, kan ansluta sig till luftledningen. Utifrån olika perspektiv, bland annat ekonomisk och tekniska mognad, visade det sig att den induktiv trådlösa elvägstekniska lösningarna kan vara bäst lämpade, utifrån ett lönsamhetsperspektiv, att implementeras på den framtida vägen, Tvärförbindelse Södertörn.
Nyckelord: Elvägssystem, Elvägsoperatör, Tvärförbindelse Södertörn, Lönsamhet,
Acknowledgement
We would like to begin by thanking SWECO for giving us the opportunity to do our master thesis with them, especially our supervisor Thomas Sjöström who shared valuable insights. We would also like to greatly thank our supervisor, at KTH Royal Institute of Technology, Lars Uppvall for helpful guidance. We also want to thank our seminar leader, Thomas Westin, and all the other master thesis students in our seminar group, for useful feedback. Oscar Nilsmo and Eric Wranne
Stockholm, Sweden, June 2020
Foreword
List of Content
1. Introduction 1 1.1 Background 1 1.2 Problem Statement 3 1.3 Purpose 3 1.4 Research Questions 3 1.5 Delimitations 4 1.6 Disposition 4 2. Research Context 6 2.1 ERS technology 6 2.1.1 Inductive Technology 7 2.1.2 Conductive Technology 8 2.1.2.1 Conductive Overhead 8 2.1.2.2 Conductive Rail 9 2.1.3 Summary 11 2.1.4 Costs Comparison 112.2 Electric Road Operator 12
2.3 Payment Model 13
2.4 Electric Buses 15
2.4.1 Depot Charging 16
2.4.2 Additional Charging 16
2.4.3 Charging while Driving (ERS) 17
2.5 BRT 17
2.5.1 Advantages and Disadvantages of the BRT System 18
2.6 Batteries 18
2.6.1 Life Expectancy 19
3. Literature Review on Economic Models Used for Calculating Electric Road Systems 20
3.1 Earlier studies 20
3.2 Investment and Calculation Theory 22
4. Methodology 24
4.1 Research Design 24
4.2 Research Process 24
4.3 Literature Review 25
4.4 Data Gathering 26
4.4.1 Primary and Secondary Sources 26
4.4.2 Data 27 4.4.3 Interviews 27 4.4.4 Assumptions 27 4.5 Data Analysis 28 4.6 Research Quality 29 4.6.1 Validity 29 4.6.2 Reliability 30 4.6.3 Generalizability 30 4.7 Research Ethics 30 5. Empirics 32 5.1 The Case 32 5.2 Road 259 32 5.3 Energy Consumption 33
5.4 The Bus Traffic on Road 259 34
5.4.1 Bus and Fuel Types 35
5.4.3 Bus Line 709 37
5.4.4 Bus Line 740 38
5.4.5 Bus Line 865 39
5.5 Costs 40
5.5.1 Bus and Maintenance Costs 40
5.5.2 Battery Costs 41
5.6 General Traffic on Road 259 42
5.7 Chapter Summary 42
6. Results 44
6.1 Calculations 44
6.1.1 Electric Road Operator Costs 44
6.1.1.1 ERS Costs 44
6.1.1.2 Charges, Incomes and Forecasts 45
6.1.1.3 Payback Period and Net Present Value 46
6.1.2 Battery Capacity Requirement 48
6.1.3 Bus and Component Transitioning Costs 49
6.1.3.1 Fuel Costs 49
6.1.3.2 Battery, Receiver & Buses Costs 49
6.1.3.3 Mechanical Arm Costs 50
6.1.3.4 Pantograph Costs 51
6.1.3.5 Lifetime Cost 51
6.2 Findings 51
6.2.1 Electric Road Operator 51
6.2.1.1 ERS Costs 51
6.2.1.2 Charges, Incomes and Forecasts 52
6.2.1.3 Payback Period 55
6.2.1.3.1 Comparisons 56
6.2.2 Battery Capacity Requirement 58
6.2.3 Bus and Component Transitioning Cost 61
6.2.3.1 Fuel Costs 61
6.2.3.2 Battery, Receiver & Bus Costs 62
6.2.3.3 Mechanical Arm Costs 63
6.2.3.4 Pantograph Costs 63
6.2.3.5 Lifetime Cost 64
6.2.4 Subsection Summary 65
7. Analysis & Discussion 67
7.1 Sensitivity Analysis 67
7.2 ERS Technology, Charges, Incomes and Payback Period 69
7.3 Battery Capacity Requirement 70
7.4 Energy Saving Potential and Vehicle Lifetime Costs 71
8. Conclusion 73
8.1 Answer to the Research Questions 73
8.2 Research Contribution 75
8.3 Limitations 76
8.4 Recommendations for Future Work 76
List of References 78
Appendix 89
Currencies 89
Payback Periods 89
List of Figures
Figure 1. The Concept of Inductive ERS (Tongur, 2018) 7
Figure 2. The Concept of Conductive Overhead (Nashed, 2018) 9
Figure 3. The Concept of Conductive Rail (Bateman et al., 2018; Nashed, 2018) 10
Figure 4. The Payment Model (Hasselgren et al., 2018) 14
Figure 5. The Research Process 25
Figure 6. Tvärförbindelse Södertörn (Huddinge - Tvärförbindelse Södertörn, 2020) 33
Figure 7. Skarpnäck - Norsborg 37
Figure 8. Huddinge Station - Länna Handelsplats (Truckvägen) 38
Figure 9. Kungens Kurva - Huddinge Station 39
Figure 10. Handen - Skarpnäck 40
Figure 11. The Pricing Development (Goldie-Scot, 2019) 41
Figure 12. Payback Period for Inductive 55
Figure 13. Payback Period for Conductive Rail 56
Figure 14. Payback Period for Conductive Overhead 56
Figure 15. The Energy Consumption of Bus Line 172 58
Figure 16. The Energy Consumption of Bus Line 709 59
Figure 17. The Energy Consumption of Bus Line 740 59
Figure 18. The Energy Consumption of Bus Line 865 60
Figure 19. The Comparison between Fuel and Electric 62
Figure 20. Lifetime Cost 64
Figure 21. Cost Comparison between Fuel and Electric 64
Figure 22. Payback Period for Inductive 1 89
Figure 23. Payback Period for Inductive 2 90
Figure 24. Payback Period for Inductive 3 90
Figure 25. Payback Period for Inductive 4 91
Figure 26. Payback Period for Conductive Rail 1 91
Figure 27. Payback Period for Conductive Rail 2 92
Figure 28. Payback Period for Conductive Rail 3 92
Figure 29. Payback Period for Conductive Rail 4 93
Figure 30. Payback Period for Conductive Overhead 1 93
Figure 31. Payback Period for Conductive Overhead 2 94
Figure 32. Payback Period for Conductive Overhead 3 94
List of Tables
Table 1. The Disposition of the Paper 5
Table 2. Comparisons through Advantages and Disadvantages 11
Table 3. Cost Comparisons (Jonsson, 2019) 12
Table 4. Actor Investment (Hasselgren et al., 2018) 15
Table 5. Pros and Cons of ERS Technologies when using Additional Charging 17
Table 6. Pros and Cons of Using Charging while Driving 17
Table 7. Interview Participants 27
Table 8. Comparison of Energy Consumption per km 34
Table 9. Standard Bus 35
Table 10. Bogie Bus 35
Table 11. Articulated Bus 36
Table 12. Bus Line 172 - Most Demanding Route 37
Table 13. Bus Line 709 - Most Demanding Route 38
Table 14. Bus Line 740 - Most Demanding Route 39
Table 15. Bus Line 865 - Most Demanding Route 40
Table 16. Historical Data of the Price for Lithium Batteries (Bateman et al., 2018) 41
Table 17. Forecasts of the Future Price for Lithium Batteries (Bateman et al., 2018) 41
Table 18. The Number of Vehicles in Sweden (Transportstyrelsen - Fordonsstatistik, 2020) 42
Table 19. Number of Electric Vehicles in Sweden (Elbilsstatistik, 2020) 42
Table 20. Implementing Costs 52
Table 21 Forecast in Sweden 2021-2030 52
Table 22. Forecast on Road 259 2018-2030 53
Table 23. Electric Vehicles and Trucks on road 259 53
Table 24. Annual Income 53
Table 25. Other Forecasts 54
Table 26. Income of Using Inductive 54
Table 27. Income of Using Conductive Rail 54
Table 28. Income of Using Conductive Overhead 55
Table 29. Comparisons with Forecasts (Inductive) 57
Table 30. Comparisons with Forecasts (Conductive Rail) 57
Table 31. Comparisons with Forecasts (Conductive Overhead) 57
Table 32. Battery Capacities and Number of Receivers 60
Table 33. Energy Consumptions and Costs 61
Table 35. The Battery Costs 62
Table 36. The Receiver Costs 63
Table 37. The Total Cost 63
Table 38. Comparison between ERS technologies (Ezer & Tongur, 2020) 74
Table 39. Bus Line 172 - Details 96
Table 40. Bus Line 172 97
Table 41. Bus Line 709 - Details 98
Table 42. Bus Line 709 98
Table 43. Bus Line 740 - Details 99
Table 44. Bus Line 740 100
Table 45. Bus Line 865 - Details 101
List of Abbreviations
BRT - Bus Rapid Transit DOD - Depth of Discharge ERO - Electric Road Operator ERS - Electric Road System FAME - Fatty Acid Methyl Ester NPV - Net Present Value
RME - Rapsmetylester
1. Introduction
This chapter will provide background information to the research topic. Further, the problem formulation, purpose, the research questions, and the delimitations of the thesis will be presented. Additionally, the disposition is also presented in order to show the structure of the thesis.
1.1 Background
The carbon dioxide emissions in Sweden were estimated to 51.8 million tonnes in the year 2018 whereas 31 percent of the total weight, i.e. 16 million tonnes, was due to emissions from the transport sector (Morfeldt, 2019). According to Naturvårdsverket (2017), road transportation accounts for 94 percent of the transport sector emissions, where passenger cars account for the largest contribution of 65 percent. The Swedish Government has set a target to become carbon neutral before year 2045. This means that carbon dioxide emissions have to be reduced by about 5-8 percent per year, during the period 2015-2045, in order to reach that target. (Morfeldt, 2019). This target would bring on major changes and technological shifts within the transport sector in order to manage the requirements related to zero net carbon dioxide emissions in the year 2045 (Nashed, 2018).
Electric Road System (ERS) is a technology that transfers the electrical power from roads to both standing-still and driving electric vehicles. Similar technologies have already existed and have been used by other vehicles, such as trams and trolleybuses. ERS technology has the potential to overcome environmental challenges and issues, such as the use of fossil fuels and air pollution. (Tongur, 2018).
as eRoadArlanda (conductive rail), Elväg E16 (conductive overhead) (Hasselgren et al., 2018), SmartRoad Gotland (inductive) (Electreon, 2020b).
A transition to an electrified transportation system will create new business opportunities whereas information regarding costs, payback time and risks will be essential to all actors involved in the transition. The transition to an electrified transportation system will also create a new actor: the electric road operator (ERO). The electric road operator will most likely work as an interconnecting link between road, electricity, vehicles and infrastructure, and be responsible for the costs and investment associated to the implementation and maintenance of ERS infrastructure. (Hasselgren et al., 2018).
Currently, ERS projects are mostly financed by the government due to high investment risks as a result of an unready market. However, a future “full scale development” of ERS will require private actor investments. (Hasselgren et al., 2018). In order to reduce risks, there must be an established market ready to use and pay for the use of ERS technology. Due to an initial small scale development, it is important to locate actors that consistently use the road which is about to be electrified and create business opportunities for both the user and the investor. (Pettersson et al., 2017).
Today, all public transport buses in Stockholm, used by Storstockholms Lokaltrafik (SL, a Region Stockholm owned company), are powered by renewable fuels, namely; HVO, RME, ethanol and biogas. However, within 10 years SL is aiming to replace 70 % of the existing bus fleet to instead be powered by electricity. Consequently, this will put pressure on bus companies currently running the public transportation in Stockholm. By introducing electric buses, Region Stockholm takes another step towards an emission free public transport and a major step for climate responsibility. In order to achieve the national climate targets set to 2030, a major share of the bus traffic needs to be replaced by buses powered by electricity. (SLL - Elbussar i kollektivtrafiken, 2020). Additionally, according to SLL and Trafikverket (2020), Stockholm is currently making investments in Bus Rapid Transits systems (BRT). BRT systems include dedicated lanes for buses, faster and more frequent operations, reduced operating costs and safer transportation. Thus, an implementation of the BRT system would provide a reliable alternative to private vehicles, in which could further reduce the environmental impact. (TransForm, 2020).
Haninge centrum, is inadequate, consequently limiting the opportunities of growth in the region. Therefore, a new road, namely Södertörn Crosslink, will be built in order to link the Southern and Northern parts of the county together. This will create business opportunities, growth, and faster & safer transportation. ( Trafikverket - Near You, 2020). However, before Södertörn Crosslink can be completed, the profitability of the investment for an electric road operator will need to be studied.
1.2 Problem Statement
The implementation of Electric Road Systems (ERS) entails uncertainties connected to politics and financing. According to Pettersson et al. (2017), the Swedish Government will account for a maximum of 300 MSEK and not more than 50 % of the total costs related to ERS pilot project developments. Thus, in the future, a large scale implementation of ERS will require private actor participation and financing. (Hasselgren et al., 2018). According to Bateman et al. (2018) there is limited knowledge regarding; the comparative performance of ERS solutions, costs, and implementation.
1.3 Purpose
This master thesis aims to investigate the costs associated with the implementation of ERS on Södertörn Crosslink. The three ERS solutions, namely: inductive, conductive overhead and conductive rail, are discussed and compared in order to provide the best suitable solution for Södertörn Crosslink, from an economical and technological perspective. Additionally, as an electric road operator will be responsible for the costs associated with implementing and maintaining ERS roads, the thesis aims to determine an approximation of the payback period for different ERS technologies. The BRT system will also be affected by the implementation of ERS and, therefore, the bus traffic may need to replace all current buses by electric buses. Therefore, the thesis also aims to study cost comparison between non-electric buses and electric buses.
1.4 Research Questions
In order to fulfill the purpose of this master thesis, the two following research questions have to be answered:
RQ1: For the electric road operator, which ERS technology is most suitable for Södertörn Crosslink from an economical and technological perspective, considering other aspects, such as aesthetics, technical maturity and safety?
- Scenario 1: All bus traffic currently operating on road 259 is electrified.
- Scenario 2: All traffic (private cars, commercial trucks, and buses) currently operating on road 259 is electrified.
The idea of these two scenarios is to find out the profitability of the investment on Söderörn Crosslink. The first scenario is to find out if it would be sufficiently profitable by using the current bus traffic. The second one is to find out if it would also require a large traffic volume, including private vehicles and trucks, in order to increase the profitability of the investment. All three ERS technologies will be studied each in both scenarios. Payback and net present value (NPV) methods will be used in order to calculate profitability.
RQ2: Is it profitable in the long term for a bus operator to transition to an electrified bus fleet, assuming the use of ERS technology?
The idea of this research question is to study the cost comparison that was mentioned at the end of 1.3 Purpose. The cost comparison will be included by, for example, fuel, battery, receiver/pantograph/mechanical arm, bus, and maintenance costs.
1.5 Delimitations
In this study, the electric road system is defined as a dynamic electricity transmission, in other words, the ability to charge vehicles while traveling. Further, this research report will only investigate the possibilities of using ERS technologies to support public and private transportation on Crosslink Södertörn, currently road 259, in Stockholm, Sweden. Therefore, other roads in Sweden will not be included in this research study. The research is focused on investigating actors assumed to consistently use the road. This, in order to provide a plausible timeframe for the payback period for the investment made by the electric road operator.
1.6 Disposition
conclusion providing results, answers to the research questions, and suggestions for future researches.
Table 1. The Disposition of the Paper
1. Introduction 2. Research Context
3. Literature Review on Economic Models Used for Calculating Electric Road System
4. Methodology 5. Empirics
6. Results
2. Research Context
This chapter is introduced by providing information regarding the electric road system (ERS technologies). Further, comparisons are made in order to increase understanding of ERS technologies' characteristics. Thereafter, information regarding the electric road operator (ERO) as well as a feasible payment model for ERS is presented. Finally, information regarding electric buses, BRT systems, and battery capacities are provided.
2.1 ERS technology
The basic idea of ERS technology is to transfer electrical power from roads to driving electric vehicles. This requires electric vehicles to have an ERS powertrain in order to receive electrical power. (Tongur, 2018). A powertrain is a system that makes sure that the vehicle moves with the aid of different components, such as an electric engine and an energy transmission system (Stevens, 2016). Electric roads will not only apply to electric vehicles with ERS powertrain, but also for other vehicles using conventional fossil-fuels. However, in order for electric vehicles to drive on roads without ERS technology, an additional power source, such as a small battery or a small diesel engine will be required. (Tongur, 2018). According to Jelica et al. (2018), an implementation of ERS technology could reduce carbon dioxide emission, from the Swedish road transportation sector, by 19 percent per year while the transportation efficiency can increase from 33 percent to 77 (Jelica et al., 2018).
2.1.1 Inductive Technology
The idea of dynamic inductive power transmission was developed by Hutin and Leblanc already in the late 19th century (Bateman et al., 2018). The idea was to provide propelled vehicles with power without any mechanical contact between receiver and powerline. However, it was not until the late 1990s, this technology was developed and applied to modern road transport. The first demonstration occured in New Zealand where a shuttle bus was successfully charged while standing still. During the last 8 years, research and development of inductive technology has significantly increased due to several factors such as; climate change, air quality, inconvenience of static charging, limitations in driving range, weight and size of vehicle batteries. (Bateman et al., 2018).
The inductive charging technology components can be divided into three categories; in-road, on-vehicle, and roadside. The in-road components consist of coils placed under the road (at the center of the traffic lane) and power cables providing electricity from the energy source. The on-vehicle components consist of secondary coils that are placed under the vehicle chassis, an electric engine (ERS powertrain) and battery. The roadside component consists of grid connections, power stations and transformers. (Sundelin & Tongur, 2016; Bateman et al., 2018; Tongur, 2018). To fully understand how the components are linked together, an illustration of ERS is provided in Figure 1.
Figure 1. The Concept of Inductive ERS (Tongur, 2018)
weather conditions (Singh, 2016). However, there are a few minor challenges regarding the inductive ERS-solution, such as technical maturity and power. The inductive technology has not been implemented beyond test and demonstration projects, consequently, the readiness of the technology is considered low. However, two pre-commercial demonstration projects, Smartroad Gotland and Tel Aviv, are currently in progress and will be tested during 2020. Additionally, wireless ERS is expected to move beyond demonstration phase in 2021. Regarding power transmission, the receiver, located under the vehicle chassi, has not reached its full potential. The receiver currently has a power energy transfer of 20 kW, however, this is expected to improve and reach 30 kW this upcoming year. (Ezer & Tongur, 2020)
2.1.2 Conductive Technology
The conductive technology can be split into two categories: conductive overhead and conductive rail. Unlike inductive ERS, the conductive technical solutions require a contact to the road (presumably overhead or rail) in order to receive electricity. The conductive overhead solution is considered to be the most established technology since it has existed in more than 100 years. The first road transport, a trolley bus, with a conductive solution was introduced in Berlin by the company Siemens Elektromoto in 1882. (Bateman et al., 2018). These two conductive technologies (overhead and rail) are explained separately in the next two subsections.
2.1.2.1 Conductive Overhead
Figure 2. The Concept of Conductive Overhead (Nashed, 2018)
Nashed (2018) mentions that there are regulations in Sweden regarding high and low voltage wires, stated by the Swedish National Electricity Safety Board. The high voltage wires have to be at least 6 meter above the ground while the low voltage wires have to be at least 5,1 meter above the ground due to security reasons. Singh (2016) mentions that ERS vehicles has to be able to connect as well as disconnect to the overhead lines. When disconnecting from the overhead lines, vehicles should have secondary source, for example batteries or hybrid-diesel engine in order to continue driving on roads.
Conductive overhead is considered to have high maturity and capable of supporting heavy vehicle traffic due to high energy efficiency and power transmission. However, the overhead wires visually affect the surrounding environment. Further, conductive overhead requires continuous maintenance and the mechanical wear is high. (Ezer & Tongur, 2020). Additionally, the technology can not be used by normal (private) cars since the overhead wires are located 5.1-6 meter above the ground. (Hasselgren et al., 2018; Nashed, 2018). Implementing conductive overhead wires on bridges and in tunnels can be challenging (Bateman et al., 2018).
2.1.2.2 Conductive Rail
transformers, communication system and grid connections. (Bateman et al., 2018). This technical solution is illustrated in Figure 3.
2.1.3 Summary
This subsection includes a short summary considering the advantages and disadvantages of the three ERS solutions discussed in subsection 2.1.1 and 2.1.2 [Tab. 2].
Table 2. Comparisons through Advantages and Disadvantages
ERS Technology Advantages Disadvantages
Inductive - No visual impact
- Suitable to all types of vehicles
- Can be used at all weather conditions - High efficiency - no need for road
maintenance
- No mechanical wear (no friction)
- Energy metering system
- The readiness of the technology is considered low. - The receiver, located
under the vehicle chassi, has not reached its full potential.
Conductive Overhead - High maturity
- high energy efficiency and power transmission
- Requires maintenance - Mechanical wear is high - Not suitable to private
cars
- Huge visual impact - Bridges and tunnels can
be a challenge Conductive Rail - Minimal visual impact
- Suitable to all types of vehicles
- high energy efficiency and power transmission
- A few performed tests and experiments - Weather’s impact - Friction and wear that
can generate particles - Dangerous for
motorcyclists due to raised surface profile on roads
- Requires high maintenance
- Mechanical wear is high
2.1.4 Costs Comparison
(Jonsson, 2019). Regarding the construction of an electricity grid, it is likely that the grid owner is responsible for the cost. (Hasselgren et al., 2018). The following table [Tab. 3] presents the costs of implementing ERS technology for each of the three solutions.
Table 3. Cost Comparisons (Jonsson, 2019)
ERS Technology Inductive Conductive Overhead Conductive Rail
Cost (MSEK per km) 10-35 9-14 5-10
Maintenance (MSEK per km)
0,150-0,525 0,135-0,210 0,075-0,150
Jonsson (2019) mentions that inductive wireless solution costs 10-35 MSEK per km, both directions. However, according to interviewee 1 (2020), the price is closer to 10 MSEK per km (both directions). A receiver costs 15 000 SEK and the number of receivers for each vehicle varies depending on the size of vehicle (interviewee 1, 2020). According to interviewee 2 (2020), the construction of conductive rail, built by Elways, will cost about 6 000 000 SEK per km at a larger scale implementation, consequently, shorter distances is expected to be more costly. Singh (2016) also mentions the electrification at a larger scale of the conductive overhead can cost about 6 000 000 SEK per km. According to interviewee 3 (2020), the construction of conductive rail, built by ElonRoad, will cost about 5-6 MSEK per km (one direction). A full-scale implementation of ERS technologies would lead to lower prices due to economies of scale (Singh, 2016). The maintenance costs of ERS is about 1,5% of the initial investment cost per km and year [Tab. 3]. However, the costs for implementation of ERS technology can vary depending on surrounding conditions. (Jonsson, 2019). A pantograph, for conductive overhead technology, is estimated to cost 30 000 - 80 000 SEK (Singh, 2016). The mechanical (or pick-up) arm, used for conductive rail technology, costs about 10 000 - 15 000 SEK for private cars and around twice that price for buses and trucks (interviewee 2, 2020).
2.2 Electric Road Operator
regarding the role of an electric road operator, namely:
1. To be responsible for taking part in the investment for the construction of the electric road infrastructure.
2. To be responsible for measuring customer energy consumption, debiting vehicles by providing an automated payment solution and identifying and collecting information to determine whether a vehicle has the right to use the electric road or not.
3. To be responsible for the operation and maintenance of the electric road.
According to Hasselgren et al. (2018), it is reasonable to assume that more than one actor will be identified as road operators since the responsibilities are different and therefore suitable for different kinds of actors. For instance, certain actors might be more suitable for having responsibilities connected to construction, operation, and maintenance of the electric road while others will have responsibilities connected to measurements, billing, and customer interactions. This paper will only focus on the first and third categories.
2.3 Payment Model
Figure 4. The Payment Model (Hasselgren et al., 2018)
The conveyor receives payments from the shipper, for example, for carrying goods from point A to point B. Similarly, the Swedish Traffic Administration (shipper), procuring all public transportation (SL) in Stockholm county, pays traffic contractors (conveyor) for passenger transport. In order to use the electric road, the conveyor needs to use a vehicle that is adapted to it. These vehicles are provided by the Vehicle Manufacturer. Further, the electric road operator receives payment from the conveyor, charging for electricity usage, grid fee and an additional user fee. In turn, the electric road operator pays the grid owner and the energy provider for the usage of the grid and for the electricity. (Hasselgren et al., 2018). As mentioned above, the electric road operator charge money for electricity usage, grid fee and user fee. The cost for electricity usage, including grid fee and taxes, is about 0,7-1,60 SEK per km, depending on specific energy consumption for the vehicle. The cost for electricity usage will be assumed to be 1,60 SEK per km for heavy truck traffic, i.e SL buses. The user fee is the cost for using the electric road. The idea behind the user fee is to cover the infrastructure investment costs made by the electric road operator. The user fee is assumed to be around 1 SEK per km. (Jonsson, 2019).
According to Hasselgren (2018), it is difficult to draw conclusions regarding how investments and risks will be divided between actors due to an unestablished market. However, four plausible business packages, on the development of ERS, are presented. The actor, responsible for measuring customer energy consumption by developing an automated payment solution, could either be provided by the electric road operator or by a new actor. However, it is reasonable to assume that the road operator will be responsible for infrastructure investments and maintenance while an additional actor has responsibility for the payment system. (Hasselgren, et al., 2018).
Table 4. Actor Investments (Hasselgren et al., 2018)
Actor Electric Road
Operator
Grid Owner Vehicle
Manufacturer New Actor Investment and Responsibility Electric road infrastructure Grid infrastructure
Vehicle Payment system
Components Infrastructure for power transmission
between road and vehicle (inductive or conductive) Grid and connection points (transformer stations) Vehicle adapted to ERS, Receiver -
2.4 Electric Buses
Today, all buses used by SL are powered by renewable fuels. Through the introduction of electric buses, Region Stockholm takes another step towards an emission-free public transport and a major step for climate responsibility. To achieve the national climate targets set to 2030, a major share of the bus traffic needs to be replaced by buses powered by electricity. (SLL - Elbussar i kollektivtrafiken, 2020)
There are three different categories of electric buses; hybrid, plug-in hybrid, and fully electrical. Hybrid buses are mainly powered by a combustion system, in other words, generate mechanical power by combustion of a fuel. Additionally, an electric engine is installed to support the vehicle with electrical power. The battery used in a hybrid vehicle is charged through regenerative braking. (Törnqvist, 2019; SLL - Strategisk Utveckling, 2017). The battery in a plug-in hybrid is bigger than the battery used in a hybrid vehicle. The battery can externally be charged by using a wall outlet or a charging station. Therefore, plug-in hybrid vehicles can rely to be powered by electricity a further distance compared to the hybrid solution. Finally, a fully electric vehicle is solely powered by electricity. (Törnqvist, 2019).
The purchase cost of an electric bus is higher than a comparable conventional bus, however, many operating costs are estimated to be lower. Additional initial costs are charging infrastructure, vehicles, electricity supply, and training of mechanics and drivers. (Lundström et al., 2019). The variable costs are considerably lower due to two main reasons:
1. Reduced energy consumption
However, due to the high initial costs for vehicles and infrastructure, the total costs for implementing electric vehicles are usually higher than for conventional vehicles (SLL - Strategisk Utveckling, 2019a).
The ways of charging electric buses can roughly be divided into 3 categories; depot charging, additional charge, and charging while driving. Which technology that is favorable to choose depends on several factors, such as tediousness, bus line travel distance, passenger capacity, and need for flexibility. (Lundström et al., 2019).
2.4.1 Depot Charging
Depot charging requires buses to be standing still in a depot for a longer period, usually during nighttime. Thus, this charging technique requires greater batteries to cover the vehicle’s energy needs while driving. By the use of depot charging, the bus can be used without any concerns regarding the transportation route, as it does not require any charging infrastructure to travel. Consequently, the route, in which the bus travels, can be very flexible.(Energimyndigheten, 2019). The batteries are charged on low effects, usually 40-80 kW. Depot charged buses usually have batteries with capacities up to 600 kWh enabling a driving range up to 150-200 km. (Törnqvist, 2019).
Advantages:
- High flexibility, no need for implementation of charging infrastructure in traffic (Törnqvist, 2019).
- Suitable for traffic with shorter driving range requirements (Törnqvist, 2019). Disadvantages
- Limited driving range. It requires the bus to charge during the day. Might lead to a need for extra vehicles. (Beekman & van den Hoed, 2016).
- The location of the depot is of high importance since it may result in long “empty bus trips” to and from the depot to recharge (Törnqvist, 2019).
- A depot is charging several vehicles at the same time which can put high demands on the electricity grid’s capacity and power outlets, as well as the maximum power outlet allowed in the depot (Lundström, A et al. 2019).
2.4.2 Additional Charging
station can provide an effect of 300-600 kW. The inductive technology can provide an effect of 200 kW (SLL - Strategisk Utveckling, 2019a).
Törnqvist (2019) and SLL - Strategisk Utveckling (2019a) discusses the advantages and disadvantages of using additional charging in Table 5.
Table 5. Pros and Cons of using Additional Charging
Advantages Disadvantages
- Smaller batteries - The ability to withstand
high effects
- No need of extra buses
- Higher maintenance costs due to charging time
- Visual impact in cities - Electric buses might
have to be locked to any infrastructure due to small batteries
2.4.3 Charging while Driving (ERS)
In motion charging requires lower effects, compared to an additional charging, an effect of 120 kW is said to be enough for a bus. At stand-stilled situations (static), a bus can need an effect of 90 kW. The low effects provide lower requirements for the electricity grid. (SLL - Strategisk Utveckling, 2019a). According to Törnqvist (2019), charging while driving is more suitable for the bus traffic that has a high frequency or has a high need for capacity. Unlike the two charging technologies (depot charging and additional charging), there are no needs of using huge battery capacities and it is enough by a battery capacity of 60 kW (applies to a 12m bus). The advantages and disadvantages of using motion charging are presented in Table 6. (SLL - Strategisk Utveckling, 2019a).
Table 6. Pros and Cons of Using Charging while Driving
Advantages Disadvantages
- Stable technology - Lower battery capacity - Fewer losses
- Visual impact - Less flexible
2.5 BRT
(Swedish: turtäthet) and characteristics: trustworthiness, rapidity, and clearness. (SLL & Trafikverket, 2020; Bösch et al., 2013). However, BRT can be defined as buses with high-quality services and includes similar capacities as urban rail systems (Bergman, 2017). BRT is a faster system than conventional city buses. An adapted infrastructure and technical solution are needed to make this possible. It also means that BRT buses get priority over other traffic. The BRT system has similar advantages as trams but with lower costs as well as a shorter implementation process. (Bösch et al., 2013; Volvo Buses, 2020; WSP, 2011). If both the BRT system and the tram system had the same budget, the BRT system would be able to provide 60% longer distances compared to the tram system (WSP, 2011). Additional advantages of using BRT, BRT buses will be able to manage heavy traffic commuting (Scania - BRT, 2020).
According to Volvo Buses (2020), an increased number of BRT will bring on a reduced number of cars in cities. Thus, the air quality will be better and also the noise in cities will be decreased. Zhang (2010) mentions that the BRT System can also provide lower energy consumption.
2.5.1 Advantages and Disadvantages of the BRT System
This subsection summarizes and presents what advantages and disadvantages of the BRT System. The previous subsections mentioned several advantages of the BRT system and the advantages include :
- Similar characteristics as the tram system
- Lower implementation costs and shorter implementation process compared to the tram system
- Providing a high frequency
- The ability to manage heavy traffic community - The priority over other traffic
- Reduced environmental impact
The BRT system includes more advantages than disadvantages. However, the disadvantages of the BRT system can be, for example, single bus lanes, where the BRT system can need extra space on roads. If a BRT bus is broken, it can cause traffic congestion to other BRT buses and it can provide limited opportunities for overtaking. (Zhang, 2010).
2.6 Batteries
usually expressed as kWh/kg, describes how much energy that is possible to store in relation to the battery’s weight. (Lantz & Aldenius, 2020).
The choice of battery för an electric vehicle varies depending on the circumstances in which the vehicle will operate. Electric buses adapted to slow charging in depots should for instance use a battery optimized for high energy storage capacity. On the other hand, electric buses using additional charging, and therefore have to be capable of recharging quickly, should be optimized too a high power transfer. In general, the better the battery is to recharge quickly the less energy storage capacity it has, vice versa. (SLL - Strategisk Utveckling, 2019c). Further, to describe how fast the energy stored in the battery can be used, the parameter C-rate has to be defined. If a battery has c-rate 1, it means the battery can be discharged within an hour. However, if the battery has c-rate 5, this means the battery can be discharged within one-fifth of an hour.
State of charge (SOC) is the available capacity left in the battery in relation to the battery’s full capacity potential. Depth of discharge (DOD) is the percentage of the capacity that has been removed from the fully charged battery.(Spiers, 2012). In other words, if the SOC is 80 % the Dod is 20 %. SOC is defined as follows:
OC(t)
S = cap cap(t) max
where cap(t) is the capacity left in the battery and cap max the full capacity potential. For instance, if the battery has a capacity potential ( cap max ) of 100 kWh and the battery has 80 kWh left, the SOC is 80 %. (Lantz & Aldenius, 2020).
2.6.1 Life Expectancy
3. Literature Review on Economic Models Used for
Calculating Electric Road Systems
This chapter presents the literature review of this master thesis. A review of earlier studies and investment & calculation theory are presented.
3.1 Earlier studies
Hasselgren (2019) has provided a calculation model that can be used to assess the costs associated with the implementation of electric road system. The model is used to calculate the financial effect on actors assumed to be involved in such a system, namely: electric road operator, grid operator, vehicle manufacturer, the government, and the Swedish Transport Administration. The calculation consist of three stages:
1. Input data 2. Calculation 3. Results
The input data used in the model provided by Hasselgren (2019) consists of information regarding daily average traffic flows, annual vehicle kilometers on ERS, number of transactions per year, cost per payment transaction, truck premiums for the purchase of electric trucks, prices for fuels (electricity and diesel) etc.
The calculation section is divided into three categories: investment, costs, and revenues. Within these sections, actor responsibilities are divided. In other words, the amount of money invested and the percentage of money received from user fees are divided and distributed between involved actors. Finally, a summation of costs and incomes are calculated in order to receive the final results. (Hasselgren, 2019).
The calculation model, provided by Hasselgren (2019), is a tool that can be used by actors in order to create a greater understanding of the financial consequences of involvement in an electric road system. However, the model lacks certain aspects. For instance, the calculation model only provides revenues and results for a given year. In other words, there is no forecast made regarding the increase and development of ERS vehicles. Consequently, the model does not consider discounted cash flows into the calculation. Further, only heavy goods vehicles are considered as input data.
busiest roads in Sweden and is considered to be of high importance viewed from a national and international perspective. The studied route is 64 km in each direction whereas 50 percent of this distance is assumed to be electrified. Consequently, this would result in 32 km of ERS in each direction. (Nashed, 2018).
Nashed (2018) made a few assumptions and limitations in order to calculate the net present value (NPV) of the ERS investment. Input values, such as average annual daily traffic, driven annual distance, and vehicle energy consumption have been assumed to be constant. However, the share of electric vehicles is expected to grow according to a growth curve. Further, all electric vehicles suitable for ERS technology are assumed to fully utilize the electric road system. In this study, an overall cost analysis was done in order to determine the profitability of the ERS investment. The cost analysis compares savings and expenditures with regard to the cost of the technology, the cost of fuels, and the cost of emissions.
By using the assumptions presented above, the cost analysis showed that the net present value, using a discount factor of 3,50 percent and an economic lifespan of 20 years, would be 350 MSEK (Nashed, 2018).
Sundelin et al., (2017), provides a calculation model intended to provide a cost analysis for all actors involved in an electric road system. The cost components examined in the calculation model are costs for ERS implementation, Grid costs, additional cost for vehicle equipment, and costs for fuels (diesel and electricity). The focus has mainly been on the electrification of trucks over 3.5 tons. The study defines the meaning of closed and open systems. During the development phase of ERS technology, implementation of ERS will mostly be considered from a closed system perspective. An example of a closed system could for instance be a road that is consistently used by certain actors, for example, bus - or road freight transport companies. In an open system, ERS technology has been implemented on a larger scale where a large variety of transportation alternatives, adopted to the technology, is developed.
Another study, provided by Taljegard et al., (2020), investigates the possibilities of a full-scale ERS implementation in Sweden and Norway. The study identifies several roads in both Sweden and Norway considered having a good potential of being implemented by ERS technology. Additionally, the study examines how much of each road that has to be electrified as well as the vehicle types best suitable to be adopted to ERS technology. This, by determining traffic volumes, infrastructure investment costs, and the potential reduction of carbon dioxide emissions. This study took all European and National roads in both Sweden and Norway into consideration. The result showed that a high average daily traffic would provide a low cost of infrastructure investment. In other words, the average daily traffic is the most crucial factor for bringing down ERS infrastructure investment costs. (Taljegard et al., 2020).
The calculation model, provided by Hasselgren (2019), shows costs, revenues, and results for a given year. Future deployment and increase of ERS vehicles are not considered. Consequently, the model can not be used for determining business opportunities viewed from a long term perspective. Therefore, it may be argued that the model does not provide sufficient information in order for potential investors to make a well-founded decision. On the other hand, the study provided by Nashed (2018), examines future scenarios and ERS development. However, the cost-benefit analysis is used for weighing and comparing project costs and benefits in order to determine whether to go ahead with a project or not. This information can be used from a societal point of view but not by private investors.
Consequently, additional information and knowledge concerning business opportunities, viewed from a long term perspective, is required for actors involved in the transition to an electrified transport system. Additionally, since ERS technology is not commercialized, a close system deployment of ERS technology requires potential actors, consistently using the road, have to be identified. Consequently, a case study will be required in order to provide reliable results regarding payback periods and potential profits. This, by providing future scenarios of ERS vehicle deployment and by the use of calculation methods using NPV and discount factors.
3.2 Investment and Calculation Theory
The Swedish Transport Administration has developed a socio-economic calculation model which is based on both current and future conditions. The calculation model consists of four steps: investigation & comparison alternatives, measure & value effects, net present value calculation and interpretation of results. The idea of this model is to make profitability assessments for any infrastructure investment. (Trafikverket, 2020c). Each step in this process is briefly described below:
alternative is the scenario where no actions are taken, in other words, if business continues as usual. (Trafikverket, 2020c).
- The second step of this process is to study and calculate effects. The effects depend on the length of the calculation period. The calculation period starts at the traffic opening year and ends at a decided year. Regarding the economic life factor, the length of the calculation period usually is decided by the investment’s economic life. The economic life for investment can vary greatly depending on the type of investment. There are factors, such as price level & base year for monetary value and economic life, that should be taken into consideration. Regarding the price level & base year for monetary value, incomes and costs have to be valued as real terms in order to relate to the general price level at the base year. This means that all future incomes and expenditures have to be discounted to present value in order to be comparable. (Trafikverket, 2020c).
- The third step of this process is to determine the net present value by looking at future costs and incomes. When incomes and costs for each year are calculated, the net present value can be measured. The net present value is used in order to calculate the present value of future cash inflows and cash outflows. This, by using the discount factor. The Swedish Transport Administration recommends that the discount factor should be around 3,50 percent. (Trafikverket, 2020c; Trafikverket, 2020d). The equation of the net present value is presented in subsection 6.1.1.3.
- The fourth and final step of this process is the interpretation of results. The measurement of profitability is the net present value and if the net present value is positive, i.e. net present value > 0, the investment is considered profitable. (Nashed, 2018; Trafikverket, 2020c).
4. Methodology
This chapter presents the research design, research process as well as what kind of methods that have been used in order to collect and analyse data. Further, reliability, validity and ethics are discussed with the intention to describe how these have been taken into account in the research process.
4.1 Research Design
The research design is a model of how to make a problem statement researchable. Choosing a suitable research design depends on what empirical material that will be collected in order to increase understanding of a certain phenomenon. The phenomenon can be described as something that needs to be understood, which corresponds to the purpose of the research. The research design of this master thesis is a case study. The case study is a way to deepen into a phenomenon, i.e. an in-depth inquiry. Conducting a case study requires gathering of extensive data, such as interviews, written documents, reports, emails and videos, and so on. (Saunders et al., 2012; Blomkvist & Hallin, 2015).
On behalf of SWECO, a Swedish Engineering Consultancy company, a phenomenon (an electrification of road 259 in Southern Stockholm, Sweden) was examined by analysing existing theories in the area of research. The case study in this master thesis is Södertörn Crosslink.
As said, the research design of this master thesis is a case study. This paper includes a literature review and empirical studies. The methods of this master thesis are qualitative interview study and quantitative data collection which is taken from secondary empirical sources. The quantitative calculations will be performed using secondary sources.
4.2 Research Process
The research process was introduced by reviewing existing literature and earlier studies within the research area. This in order to gain a broader understanding of electric road systems and its challenges and uncertainties. Thereafter, a research question was developed and formulated based on the project description and knowledge gained from existing theory. The research was investigated based on two viable scenarios. Further, the next step in the research process was empirics. In this section numerical data was collected, analysed and used as input data in different calculations in order to calculate and provide results. Finally, the findings gathered from empirics and theory were used to answer the research question. Initially, the research started out as a qualitative study, however, as the project proceeded, additional information from theory and empirics as well as feedback from peers resulted in a reconsideration of the research design. As Blomkvist and Hallin (2015) mention, a research project is not a linear process. With this said, this research process has been iterative, where the content and structure of the report constantly has improved over time due to feedback from peers and supervisors. In the following Figure 5, the structure of the process is shown.
Figure 5. The Research Process
4.3 Literature Review
reading up” and this is a way to read as many literature as possible in order to find something relevant to this study (Blomkvist & Hallin, 2015).
The literature and theories in this master thesis were found by using search engines or databases such as Google, Google Scholar, KTH Primo and Digital Scientific Archive (Swedish: Digitala Vetenskapliga Arkivet). The literature was also collected by contacting concerned persons from, SWECO, the Swedish Transport Administration and the Administrative Authority in Stockholm (Region Stockholm). The most common search words in this study were, for example, “ Electric Road Systems”, “Crosslink Södertörn” and “Bus Rapid Transit”.
4.4 Data Gathering
The data gathering methods used in this research were chosen based on what was best believed to assist in answering the formulated research question. This research has mainly collected numerical data through email contact with the Administrative Authority in Stockholm, through telephone interviews and mail conversations with actors having an important connection to the investigated topic, and from earlier studies. By the use of quantitative data, this research has been able to provide new facts and insights to the investigated research area. The following subsection presents how the data was gathered and managed, including primary, secondary sources and data that were assumed to be able to answer the research question.
4.4.1 Primary and Secondary Sources
4.4.2 Data
This master thesis used a document gathering as a data gathering method. The document gathering-method is a way to collect data, such as mails and official documents, in order to establish empirical materials. (Blomkvist & Hallin, 2015). The data were, as said, collected through the Administrative Authority in Stockholm County, Sweden, from interviews and from earlier studies. Further, data concerning the number of non-electric and electric vehicles in Sweden were found through statistics compiled by the Swedish Transport Agency and Elbilsstatistik.
4.4.3 Interviews
This subsection presents the interviewees involved in this study as well as how the interviews have been executed. Information gathered from interviews was used to validate the information obtained from earlier studies, e.g. advantages & disadvantages and costs, of each technical ERS solution. Mainly closed-ended questions were asked in which could be answered by a simple yes or now, or by providing a straight answer. For example, questions regarding efficiency, electricity transmission capacity and cost estimates were asked where simple and straight answers were obtained. The interviews were done by mails and telephone conservations during the master thesis-period (February - May) [Tab. 7].
Table 7. Interview Participants
Interviewee Name Role/Company Interaction
Interviewee 1 Stefan Tongur Business Development Manager/Electreon
Mail and Telephone
Interviewee 2 Gunnar Asplund CEO and
founder/Elways
Telephone Interviewee 3 Dan Zethraeus Innovation
manager/ElonRoad
The company Electreon develops the inductive solution while both Elways and ElonRoad develop the conductive (rail) solution.
4.4.4 Assumptions
This subsection presents the assumptions used in this research study. The assumptions are presented in a bulleted list, with brief descriptions to mention why they were used:
- The Number of Electric Vehicles on Södertörn Crosslink
scenarios from earlier studies provide information regarding the number of electric and non-electric vehicles in the future. The ratio between electric vehicles and non-electric vehicles in Sweden is assumed to apply to Södertörn Crosslink as well. - Energy Consumption of Electric Buses and Non-Electric Buses
The energy consumption is assumed to be constant, i.e. the energy consumption is assumed to only be dependent on the driven distance. However, in real life, the energy consumption varies. This was used to simplify calculations.
- Electric Road Operator
The role of the electric road operator is not yet formally defined. However, in this paper, the electric road operator is assumed to be responsible for the implementation of ERS technology (category 1, see 2.2 Electric Road Operator ) as well as the maintenance costs that come with it (category 3). The second category, i.e. the responsibility of measuring customer, debiting, identifying, and collecting information will not be part of this paper.
- Bogie Buses replaced by Articulated Buses
Bogie buses (buses that are 14 m long) are assumed to be replaced by articulated buses (buses that are 18 m long ) due to population growth in Stockholm County. According to SLL - Verksamhet (2020), the population growth will be increased by 33 500 people annually in Stockholm county. Therefore, an increased need for public transport capacity.
- The Payback Period
The number of electric vehicles was forecasted for 2030, the same year Södertörn Crosslink is estimated to be finished. The number of electric vehicles was assumed to be constant after 2030. This, to calculate the payback period from a worst-case scenario. The payback period includes a discount factor and according to Nashed (2018), the discount factor is 6-12 percent. Due to the large margin, a discount factor of 9 percent is used in this study.
- Maintenance Cost
The maintenance cost of diesel buses is about 120 000 SEK per year (Misanovic et al., 2018). Buses with other propellant types should have the same components as diesel buses, since many parts are still the same e.g. engines and oil filters. Thus, maintenance cost is assumed to apply to buses with other types of propellants as well.
4.5 Data Analysis
were developed. These models were used with the aim to provide results in which could be analysed and compared to earlier studies. There are two types of quantitative data: discrete and continuous. Continuous data is the data that falls on a continuum and that can be measured. (Saunders et al., 2012; Zangre, 2019). Some examples of continuous data obtained in this study is time, energy consumption and distance. Discrete data is data that has distinguishable spaces between values. (Saunders et al., 2012; Zangre, 2019). Some examples of discrete data obtained in this study could be the number of buses, number of departures or the number of vehicles on road 259.
In order to get a good overview of the collected data, it was all organised into different tabs in the computer program Excel. By using Excel, results could easily be changed by adjusting the input data to the equations. Since telephone interviews and email conversations have mainly consisted of concrete and closed questions, there has been no need for coding the data. However, all data gathered from interviews has been compared and analysed by looking at results from earlier studies. This in order to achieve as reliable results as possible.
4.6 Research Quality
The research quality has to be taken into consideration in order to avoid the possibility of incorrect content in the research paper (Saunders et al., 2012). Reducing the possibility of incorrect content can be done by increasing the research quality with the aid of validity and reliability. According to Blomqvist and Hallin (2015:52-53) validity and reliability can briefly be explained as “... validity entails studying the right thing while reliability entails studying it in the right way”. The validity and reliability are described in subsections separately.
4.6.1 Validity
4.6.2 Reliability
The research reliability is the degree to which a research may be repeated and still produce stable and consistent results (Research-Methodology, 2019). In other words, independent researchers should be able to replicate the process and arrive at the same results as the original study. (Blomkvist & Hallin, 2015). The collected data is assumed to have high reliability as it has been collected from different sources still providing same or similar results. Since all collected data has been systematically compared to each other, one may argue that the reliability is increased. However, some of the collected data, such as battery prices, fuel prices, bus prices etc, will most likely change in the future. Therefore, the reliability of the results will reduce over time. However, the input data in the Excel program can easily be changed. Therefore, the program developed will be reliable to use in future scenarios.
4.6.3 Generalizability
Generalizability, or external validity, is to what extent the findings of the study can be used at other studies (Shantikumar, 2018). In other words, how well the theory will be able to apply to other settings (Gibbert et al., 2008). As said, a case study is chosen as the research approach for this master thesis. Blomkvist and Hallin (2015) and Gibbert et al. (2008) mention that one or more case studies cannot result in statistical generalizability since findings from a specific case many times cannot apply to other case studies even if they are of the same nature. However, this does not mean that case studies are devoid of generalization and should therefore be overlooked. The type of generalizability for a case study is analytical generalizability. The analytical generalizability means that the results, supported by the discussion section, can be applicable to other studies. (Blomkvist & Hallin, 2015). The findings in this master thesis only apply to the case study Södertörn Crosslink since the parameters only apply to this master thesis. However, the results of the master thesis can be applicable to other case studies when it comes to the profitability and the choice of ERS technology.
4.7 Research Ethics
This master thesis follows the four principal requirements that were stated by the Swedish Research Council: the information requirement, the consent requirement, the confidentiality requirement, and the good use requirement (Blomqvist & Hallin, 2015; Vetenskapsrådet, 2020). These four requirements are described separately below and how each requirement was treated in the research approach.
