The objective of the Task 33 (2016 – 2019) is to analyse and assess the current state of technology and demonstration experiences of battery electric buses towards a broad market roll out. This covers on one hand the bus technology, e.g. battery or capacitor system, and on the other hand the charging infrastructure, e.g. fast charging stations at the bus stop and its optimal integration in an urban infrastructure, e.g. synergies with trams, metro or trolley bus systems. The task work is to be achieved with analysis of ongoing demonstration projects and the start of the roll out phase of battery electric buses worldwide. Based on this, the future perspectives and challenges for battery electric buses are to be analysed and described. This includes the identification of major challenges e.g. technology, costs, public acceptance and the necessary R&D demand. Finally, the key aspects for a successful broad introduction of battery electric buses and the necessary framework conditions are concluded.
The work is to be done in close collaboration of the relevant stakeholders from the three focus groups:
The outputs are to be continuously documented and disseminated via presentations, workshops, conference contributions and publications.
The major activities are:
The most important activity of the working method (Figure 1) is the organisation of workshops in different member countries to involve the stakeholders in the value chain of battery electric buses, e.g. providers of public transportation services, system and technology providers, research institutions. The organisation of workshops with participation from industry, research organisations, technology policy experts and governmental institutions provides an international basis for the exchange of information on the relevant activities. The focus of the expert workshops is to analyse, discuss and document two areas:
The workshops are to be combined with site visits to demonstrate on-going activities of battery electric buses in daily life application.
The results of this task pertained to the key reasons for adoption for battery electric buses including the technological aspects, Experiences from demonstration projects and experiences, Fleet management, Performance indicators, Environmental aspects, Economic aspects, and the Comparison to other low-or zero-emission bus systems.
The charging systems are an essential component, when discussing battery electric bus implementation. Harmonised charging systems are necessary for fast and/or opportunity charging on the route or in the depot. Currently there is no “one size fits all” charging solution as the site specific framework conditions have to be considered. For effective grid load management, a charging management of the bus fleet is essential; furthermore, a system approach combining bus operation and charging strategies is necessary – bus and charging infrastructure must be optimally linked.
One very important aspect for the further future development of battery bus systems is advanced fleet management. Fleet management can be utilised to optimise the operation of electric bus systems. Especially when high scale OC bus systems are considered, fleet management has functions to ensure optimal charging operations.
The key performance indicators for battery electric bus systems are:
As additional indicators the following are relevant:
Besides battery electric buses, hydrogen fuel cell buses, and synthetic biofuels and E-fuels (made from CO2 and electricity) with an internal combustion engine (ICE) are also future options for low- or zero-emissions bus systems. The application of biomethane and hydrotreated vegetable oil (HVO) is an option; in future the application of synthetic biofuels is also possible.
Focusing on current trends it can be observed that the battery capacity of both OC and DC buses is continuously increasing. Different sizes of battery electric buses are available, ranging from 12, 15 and 18 m buses. For the design of new light weight battery electric buses, more aluminium and plastic components are set to be developed and integrated in innovative new use concepts.
Mass roll out of battery electric buses does however come with some main challenges:
Focusing on the further development of battery electric buses, R&D needs are identified in the following fields: