Master Thesis MSc Supply Chain Management “Preparing for a zero-emission fleet at RET” Student: Coach: Co-reader: Guillermo A. Beuchat Beroiza Dr. Pieter van den Berg Dr. Jan van Dalen Student number: 450432 [email protected] [email protected] [email protected] June 15th 2017 “Preparing for a zero-emission fleet at RET” Guillermo A. Beuchat Beroiza | [email protected] Preface The copyright of this Master Thesis rests with the author. The author is responsible for its contents. RSM is only responsible for the educational coaching and cannot be held liable for the content. This Thesis was written with the valuable collaboration of Planning Department of RET. They provided knowledge, data, and very detailed feedback during the writing process. Also, guidance from the Coach and the Co-reader and their feedback as part of the academic community was a key part of the process. Executive Summary RET provides public transport services in Rotterdam Metropolitan Region, operating Metro, Tram, and Bus networks. RET has a fleet of 278 buses running on diesel fuel, and in the following years, they will replace the diesel fleet with Zero-emission buses. The Planning Department of RET is responsible for many activities of the Planning Process. One of the most important activities of the process is designing the vehicle schedules, which contain a detailed plan of all the trips that shall be executed by the bus fleet to fulfill the transport service. The current vehicle schedules are designed to be executed by the diesel fleet. The Planning Department of RET believes that moving to a Zero- emission fleet may have an impact on the Planning Process, since the vehicle schedules generated may be impossible to execute using Zero-emission buses given the technologies available in the market. This thesis attends the above-mentioned problem by focusing on two objectives: to identify the aspects related to a Zero-emission fleet that may have an impact on the Planning Process, and to quantify those impacts on the vehicle schedules. To achieve both objectives, this thesis stands over a previous research conducted by the Planning Department of RET, in which a model was developed. To identify the aspects related to a Zero-emission fleet that may have an impact on the Planning Process and were not considered in the previous model from RET, a literature review was conducted. This thesis found that the relevant aspects to be considered were those which impact the energy consumption, charging time and range of the bus. A relevant aspect which has a big impact on energy consumption is the Heating, Ventilation, and Air Conditioning unit. Studies suggest that these units can account for up to 40% of the total energy consumed by the vehicle. Another aspect is related the characteristics of the route. Contrasting results were found in literature regarding this topic; while some studies suggest that suburban routes consume much more energy than urban routes (differences as big as 50%), other studies suggest that there is no difference at all. Another aspect is the location, power output and capacity of charging stations, which is relevant for the range and charging time. Also, preparation for a Zero-emission fleet should consider being able to handle queues in charging stations and establishing certain rules for charging-related decisions. To quantify the impact of the Zero-emission aspects on the vehicle schedules, the model developed by RET Planning Department has been enhanced by incorporating the Zero-emission aspects found in the literature review. Many studies focus on measuring the impact of these aspects on energy consumption, but only a few of them analyze the impact on vehicle schedules. The approach used by the latter consists of incorporating the Zero-emission conditions as variables and constraints into the schedule generation problem. In contrast, the approach followed by this thesis consists of evaluating the current schedules under the conditions imposed by the Zero-emission fleet. 2 “Preparing for a zero-emission fleet at RET” Guillermo A. Beuchat Beroiza | [email protected] Vehicle schedules contain several trips to be executed by vehicles. These trips are organized using “blocks”, which are sets of trips to be executed by one vehicle. To evaluate the vehicle schedules under Zero-emission conditions, a simulation tool was developed and a set of “performance indicators” was proposed to assess the results. The main indicator is the number of “feasible blocks”, where “feasibility” is determined by the state of charge of the batteries of the vehicle. If a block of the vehicle schedule pushes the battery level below certain predefined parameter, the block is considered “infeasible”. This study simulated a vehicle schedule with 1540 trips, allocated in 128 blocks. A base scenario with reasonable initial values based on literature was set, which resulted in 83 feasible blocks. Then, parameters were modified to measure their impact on the number of feasible blocks. The Heating, Ventilation and Air Conditioning unit has a great impact on the schedule. If switched on, the number of feasible blocks decreases from 83 to only 28 blocks. The characteristics of the route are also relevant. If there is no difference between energy consumptions of urban and suburban, and the consumptions are close to 1 [kwh/km] (as observed in some studies), the number of feasible blocks increases to 124 (97% of the total blocks). Other aspects were found to have a great impact as well. Size of the battery pack is critical, since installing batteries of 50 [kwh] capacity makes all the blocks infeasible, while batteries of 400 [kwh] allow 124 feasible blocks. Also, power output of the charging stations can make a big difference. If stations provide less than 150 [kw] of power, buses are not able to charge during the night and may begin the next day without full charge. When power is above 300 [kw], almost no improvement is observed in the number of feasible blocks. Other aspects turned out to be less significant from the planning perspective. For example, the charging technology chosen and the addition of charging stations in certain places made almost no difference in the feasibility of blocks. This thesis concludes that the current vehicle schedules of RET are not completely feasible under Zero- emission conditions, so modifications are required. It identifies some aspects of the Zero-emission fleet which have a big impact on the feasibility of the blocks and therefore should be considered by the Planning Department to adapt the vehicle schedules. 3 “Preparing for a zero-emission fleet at RET” Guillermo A. Beuchat Beroiza | [email protected] Index Preface 2 Executive Summary 2 Index 4 Figures Index 6 Tables Index 8 Abbreviations used 9 Units used 9 1. Introduction 10 Objectives and structure 11 2. Context description 11 2.1. Zero-emission technologies 11 2.1.1. Zero-emission technologies for buses 11 2.1.2. Support equipment technology 13 2.2. Experiences with Zero-emission bus fleets in other cities 16 2.3. Current fleet at RET 16 2.4. The Planning process in RET 17 2.5. Model developed by RET for Zero-emission project 19 3. Identifying relevant Zero-emission aspects not included in the current model (Phase I) 21 3.1. Heating, Ventilation, and Air Conditioning units (HVAC) 21 3.2. Characteristics of the route (driving cycle) 23 3.3. Other parameters 28 3.3.1. Efficiency of energy transfer during charging process 28 3.3.2. Transmission system 30 3.3.3. Regenerative braking 30 3.3.4. Queues handling 31 3.4. Overview of Enhanced model 31 4. Quantifying the impact of relevant Zero-emission aspects on schedules (Phase II) 33 4.1. Proposed methodologies to incorporate relevant Zero-emission aspects into the enhanced model 33 4.1.1. Methodology to incorporate HVAC unit into the enhanced model 33 4.1.2. Methodology to incorporate the driving cycles into the enhanced model 33 4.1.3. Methodology to incorporate the charging stations efficiency into the enhanced model 36 4 “Preparing for a zero-emission fleet at RET” Guillermo A. Beuchat Beroiza | [email protected] 4.2. Simulation tool overview 36 4.3. Calculation of performance indicators for the schedule provided 37 4.4. Assumptions of the simulation 38 4.5. Charging rules 39 5. Impacts of Zero-emission aspects on vehicle schedules 39 5.1. Base run settings 40 5.2. Base run results 41 5.3. Impact of modifying the “Layover Time for Charging” parameter 43 5.4. Impact of deleting charging stations. 44 5.5. Impact of HVAC unit on schedule 46 5.6. Impact of consumptions of driving cycles on schedule 47 5.7. Impact of charging stations power on schedule 48 5.8. Impact of charging stations power on schedule 51 5.9. Impact of battery pack size on schedule 51 6. Conclusions 53 6.1. Main findings in Phase I 53 6.2. Main findings in Phase II 53 6.3. Discussions 55 6.4. Recommendations and follow-up research 55 References 57 Appendix 1: Current fleet of RET 61 Appendix 2: Inputs of the simulation tool 63 Implementation of enhanced model in MSEXCEL 63 “Parameters” worksheet 63 “ConsumptionPerRoute-Pattern” worksheet 64 Vehicle schedule in MSEXCEL format 65 Appendix 3: VBA program of the simulation tool 67 Development of simulation program in VBA. 67 Appendix 4 Outputs of the simulation tool 70 “Result_VehView” worksheet 70 “Result_ChgView” worksheet 71 “Performance” worksheet 72 “Graphs_VehView” worksheet 75 5 “Preparing for a zero-emission fleet at RET” Guillermo A. Beuchat Beroiza | [email protected] Figures Index Figure 1: Pictures of the most common charging technologies 14 Figure 2: HFC bus in London (left).