Public transport is crucial for the functionality of urban systems. Globally, much attention is being given lately to reducing transport’s environmental impacts by shifting towards fossil-free fuels, while also improving service availability. In this context, electrification of bus transport is gaining popularity because of the high energy efficiency improvements that can be accrued, together with low emissions and noise reduction compared to conventional buses.
Although several studies focus on engine performance and powertrain characteristics of electric buses for individual demonstration projects, there are few studies that analyze the role of bus charging technologies and charging strategies. Gathering and systematically analyzing existing experiences from electric bus demonstration projects around the world is necessary for understanding the benefits and drawbacks of emerging solutions. The aim of this paper is to fill this gap and offer a comparative analysis of various alternatives for electric bus charging. What are the characteristics of each technology and what are the main themes emerging when it comes to implementation?
The analysis draws from experiences around the world, which are systematically evaluated under guidelines of meta-synthesis, reviewing existing literature and complementing it with expert knowledge gathered from an electronic survey. The respondents belong to stakeholder groups involved with electric bus demonstration projects, such as public transport authorities, transport service operators, charging technology providers, municipalities, regional authorities, and academia. Particular attention is given to the Nordic region, where several successful initiatives are already in place.
The preliminary results show a variety of choices among charging technologies, and it is not uncommon to have different strategies combined in the demonstration projects. The survey responses indicate that stakeholders participate in such projects primarily in order to gain knowledge about the technologies tested, as well as due to the potential environmental benefits from bus transport electrification. Common unexpected issues faced during project implementation include increased costs for infrastructure installation, difficulties in communication between the stakeholders involved, as well as unexpected technology compatibility issues.
The decisive factors when choosing charging technologies are related to market-readiness, cost-effectiveness, replicability and operation costs of available technologies, but also the institutional set up that allow for the development of certain options over time. The analysis of the survey results links charging technologies and strategies to their advantages and disadvantages as acquired from experience, and explain the factors behind the choices made.
The results are useful in helping to enrich the knowledge basis on transport electrification, shifting from individual empirical findings to a generalized framework for evaluation of technology choices when it comes to charging infrastructure. In this way, we extract knowledge that facilitates choosing the most appropriate charging technology, designing implementation strategies and avoiding pitfalls that have already been encountered elsewhere.
Nationell Konferens I Transportforskning, 18-19 OKTOBER 2016, Lunds Universitet