National Academies Press: OpenBook

Battery Electric Buses—State of the Practice (2018)

Chapter: Chapter 7 - Conclusions

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Page 81
Suggested Citation:"Chapter 7 - Conclusions." National Academies of Sciences, Engineering, and Medicine. 2018. Battery Electric Buses—State of the Practice. Washington, DC: The National Academies Press. doi: 10.17226/25061.
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Page 81
Page 82
Suggested Citation:"Chapter 7 - Conclusions." National Academies of Sciences, Engineering, and Medicine. 2018. Battery Electric Buses—State of the Practice. Washington, DC: The National Academies Press. doi: 10.17226/25061.
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Page 82
Page 83
Suggested Citation:"Chapter 7 - Conclusions." National Academies of Sciences, Engineering, and Medicine. 2018. Battery Electric Buses—State of the Practice. Washington, DC: The National Academies Press. doi: 10.17226/25061.
×
Page 83
Page 84
Suggested Citation:"Chapter 7 - Conclusions." National Academies of Sciences, Engineering, and Medicine. 2018. Battery Electric Buses—State of the Practice. Washington, DC: The National Academies Press. doi: 10.17226/25061.
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Page 84

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81 The number and variety of BEB models on the market have grown significantly in the last decade as has the number of BEB deployments. Most of the agencies surveyed for this synthesis report have BEB fleets that are up to 10% of their total fleet size, although some have fully elec- trified their fleets or are on the pathway to full electrification. The growth in BEB deployments is due to community and transit agency recognition that BEBs are cleaner, quieter, simpler, and smoother than their conventional bus counterparts due to their all-electric propulsion and auxiliary systems. These attributes result in zero tailpipe emissions, zero dependence on foreign oil, better ride quality and experiences for passengers and drivers, and the potential for lower operational costs. This is a unique point in time for the emergence of clean transportation technologies. BEBs are being deployed in greater numbers at transit agencies across the country and are being oper- ated successfully in revenue operation. With some exceptions, the BEB fleets are small and have only been in service for around 5 years or less. Much of the bus development and successful deployment practices have been accomplished through trial and error. There are many variables that go into procuring and deploying a BEB fleet, both with the buses and with the associated charging infrastructure. Choosing the right BEB type and charging method in this complex space can have significant implications on bottom line costs and operational impacts. While much has been learned about what works and what does not work when deploying BEBs, more experience, information, tools, and data are needed to be able to reduce the costs associated with BEB fleets and their operational impacts. The approaches of transit agencies to BEB deployments have been varied, creative, and full of lessons learned. This synthesis was completed through a literature review, a comprehensive agency survey, and multiple case examples to better understand and report the state of the practice for BEB deployments to date. This synthesis report will be a valuable resource for both agencies just beginning to add BEBs to their fleet as well as for experienced BEB fleet owners. The literature review revealed interesting data-driven statistics about planning and opera- tions. For example, it confirmed that the capital costs of BEBs are more expensive than conven- tional buses but that costs are coming down and there are opportunities for transit agencies to solicit external funding to offset costs. These costs can also be offset by reduced maintenance costs and operational costs. However, operational costs can be heavily dependent on utility rates, despite an almost four times improvement in fuel economy. Understanding utility rates, their effect on the business case, and the potential to optimize rate structures for BEBs is a need for the industry. Also, BEB availability is reported to be comparable to that of CNG buses, 90% to 93% availability for BEBs versus 94% availability for CNG buses, according to NREL. Ultimately, close coordination with stakeholders including bus OEMs, utilities, and local officials was identi- fied as an important component for a successful BEB deployment. C h a p t e r 7 Conclusions

82 Battery electric Buses—State of the practice The survey results provided information regarding a broad variety of BEB deployments and topics. At the time it was conducted, the survey captured 163 BEBs either delivered or on order (not including options). Most of the responding transit agencies have been operating BEBs any- where from 12 to 40 months. The types of BEBs that are being procured vary widely from bus size to battery size to charge type (about half are using on-route overhead charging, a few are using on-route wireless, and the rest are relying solely on plug-depot charging) to charger size (in terms of charge power). All transit agencies rated the forthcoming APTA Zero Emission Bus Standard Bus Procure- ment Guidelines as important. Almost all agencies stressed the importance of continued public investment in the deployment of BEBs. Only nine agencies stated that they factored electric- ity rates and/or demand charges into their decisions to purchase BEBs and only about half of respondents did a life cycle cost analysis during the procurement. More than half of the transit agencies used their own experience in combination with OEM predictions and bus trials to eval- uate vehicle range, select suitable routes, and determine what type of charging method would be the best fit for their agency. But only a third of the transit agencies used advanced modeling and simulation techniques that could have likely been used to predict some of the operational issues that were reported. The majority of transit agencies responded that these tools of this nature would be beneficial when making decisions regarding range predictions, utility rate analysis, and life cycle cost analyses. More than half of the transit agencies installed the infrastructure themselves instead of using the bus OEM, infrastructure provider, or consultant and did so before the BEBs arrived. For most agencies, the installation was smooth because the utility and power requirements were well communicated and understood by all stakeholders (OEMs, local utilities, construction archi- tecture and engineering companies, public works, local and state DOTs, and local planners). Almost all of the agencies own their charging infrastructure. Despite the majority of transit agen- cies using on-route charging having low-traffic density and pull-off lanes or pull-in driveways, 4 out of 11 transit agencies still had incidents associated with other vehicles colliding with the infrastructure. As reported, many transit agencies were primarily looking to the initial BEB deployment to gain experience with the technology and to understand how it works within their opera- tion and service. It is understandable that a third of the transit agencies were not planning in advance for scale up at this stage. However, half of the transit agencies did anticipate hav- ing issues with not having adequate depot or on-route property and right-of-way to support charging infrastructure for full BEB fleets, a quarter of the transit agencies anticipated having issues with adequate electrical power, and half of the transit agencies anticipated having issues with adequate resources (e.g., scheduling and making manual connections) for charging BEBs at scale. Transit agencies trained an average of 70% of their drivers and an average of 58% of the maintenance staff to support their BEBs, and the training was predominately provided by the bus OEM for both the bus and the supporting infrastructure. Training hurdles included the unfamiliar nature of battery SOC for new operators and understanding range capacities of different products and batteries. Agencies stated that having a factory technical represen- tative on site and operating an initial shadow service worked well to promote maintenance and training learning. To accommodate the unique operational needs of BEBs, 60% of respondents reported adjusting their schedules. Layover times were the second most adjusted at 40%, followed by

Conclusions 83 bus blocking (20%), and the number of buses serving a route (13%). However, 33% of transit agencies did not make any adjustments. The general consensus of agencies is that on-route charging works well, as long as there is adequate planning, testing, training, and practice docking. After going through the process of initial deployment and shakeout, BEB availability was an average of 86%, depot charging availability was 99%, and on-route charging availability was 86%. The agencies reported little maintenance issues and liked the relative simplicity of the vehicles. The challenges that agencies have encountered with BEB maintenance center on the learning curve associated with the new technology, which can be addressed with robust training programs and eventual experience. A majority of the agencies (79%) have not had issues with the traction battery. Agencies report that spare parts inventories for BEBs are either the same or lower compared with diesel buses because BEBs require fewer parts (for instance, there is no transmission) and have a longer brake life since they do not need to be replaced as often. However, the availability of parts and long lead times have been problematic due to the relatively small scale of BEB deployments and the lack of a mature supply chain. The majority of the transit agencies are tracking their maintenance and operational expenses. One-half of transit agencies also track the social, envi- ronmental, and health benefits of BEBs, specifically those related to GHG emission reduction. The California agencies also track GHG emissions because many of them used state funds that required it. For the survey overall, 77% of transit agencies that responded are either satisfied with the BEBs (ranking between 4 and 7 on a scale from 1 to 10) or very satisfied (ranking between 8 to 10), and 86% of transit agencies plan on purchasing more. While one agency has already gone fully electric, three agencies responded that they intend to be fully electric by years 2020, 2025, and 2030. The case examples provide context to the report by identifying specific challenges and the methods that agencies used to solve them. AVTA experienced significant changes in energy consumption (in turn, poor range and higher operational costs) due to inefficient driving habits. To address this challenge, AVTA chose to provide recurrent training and is also considering an incentive program to promote efficient driving. AVTA is also using an advanced charge management system that allows them to optimize bus charging based on the needs of the fleet, to check battery SOC, and to monitor individual driver’s performance, among other smart controls. The City of Seneca had issues determining the best utility rate structure for their operation. The city has the option of one rate schedule that includes demand charges but lower energy costs and one rate schedule without demand charges but with higher energy costs. The demand charges introduced unexpected driver habits when they were choosing where to charge and increased their station maintenance costs. The transit agency then switched to a rate sched- ule without demand charges; even though the electricity costs might be higher, the total cost of ownership is expected to be lower. Foothill Transit’s public satisfaction with BEBs was rated lower than expected on the survey since many of their passengers expressed frustration with the technology due to associated layover increases and schedule delays. Many of Foothill Transit’s passengers use transit as their primary means of transportation and/or for commuting to work, and the benefits of the technology did not outweigh the drawbacks. Maintaining schedules and minimizing layover times are important for many transit agen- cies incorporating electric bus technologies, and methods or tools should be developed to allow for this during the planning stage. King County Metro focused on working with the bus OEM to improve the operator experience of the new electric bus model. On the planning side, King County Metro is focused on addressing scale-up issues for their BEB fleet that include

84 Battery electric Buses—State of the practice bus-charger communication with multiple chargers in close proximity; dealing with space constraints when installing chargers in large quantities; managing the competing needs of BEBs that share on-route chargers, especially during irregular operations; and charge time optimization. Another general case example finding is that some agencies are opting to charge at fast chargers (overhead conductive or wireless) that are either close in proximity to the bus depot or at the maintenance bays. These agencies are choosing to use plug-in depot chargers only for back-up situations. Fast chargers installed at the depot can be a more economical option than plug-in chargers due to the faster charge times, space constraints, and labor require- ments. However, agencies with plenty of space at the depot do not have a problem with plug-in charging for larger scale deployments. Many of the challenges uncovered during the case examples are being solved through better coordination, better training, and more robust planning, including the use of advanced planning methods and tools at the outset of the project.

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TRB's Transit Cooperative Research Program (TCRP) Synthesis 130: Battery Electric Buses—State of the Practice documents current practices of transit systems in the planning, procurement, infrastructure installation, operation, and maintenance of battery electric buses (BEBs). The synthesis is intended for transit agencies that are interested in understanding the potential benefits and challenges associated with the introduction and operation of battery electric buses. The synthesis will also be valuable to manufacturers trying to better meet the needs of their customers and to federal, state, and local funding agencies and policy makers.

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