The ambitious goal has been defined, and the road ahead is currently still open: As of the end of this decade, Daimler Buses intends to offer all-electric coaches with its Mercedes-Benz and Setra brands.
To accelerate development, Daimler Buses has teamed up with renowned research institutes and experts from the industry to form the Electrified Coach project – ELCH in short. The project is funded by Germany’s Federal Ministry for Economic Affairs and Climate Action.
City buses with an all-electric drive, such as the Mercedes-Benz eCitaro, are now a familiar sight on the streets of many German and European cities. Electrically powered coaches is a different story. Their development is far more challenging, as there are many high hurdles to overcome before the coaches can be deployed. Requirements for long-range transport, flexibility in use, battery charging on the go, high payloads and the space required for passengers and luggage are indispensable and in part contradictory. No bus/coach manufacturer has yet succeeded in developing a battery-powered coach that can cover workable ranges as well as availability for a wide variety of operating conditions.
Michael Klein, Head of Product Development and Production Daimler Buses: “We are delighted to be the only bus/coach manufacturer able to bring our development expertise to the ELCH project. As a technological pioneer in the industry, we can deal with the topic both quickly as well as comprehensively and in a practical way.”
The objective of the Electrified Coach project– ELCH for short – is the development of a modular drivetrain and two emission-free and practical demonstration vehicles in the next four years. They will then be tested under real operating conditions.
Partners will take a holistic approach to the ELCH project. First of all, a modular drive system with a view to energy consumption, range, driving performance and battery service life will be examined in the concept phase in a pilot project. Synergies with components from the “Daimler Truck” truck division will be taken into account.
In the second step, factors such as overall costs, environmental impact and possible integration into existing operating concepts of bus/coach companies will be incorporated into the results. Based on the concept evaluation, two prototype drivetrains will then be developed and integrated into the demonstration vehicles. This will enable testing under real operating conditions.
The findings from the construction of the demonstration vehicles will form the basis for the planning of cost-effective production and assembly processes for electrically powered coaches. This, in combination with the modular product approach, will enable a fast production start-up.
Acceptance of the technology largely depends on its suitability in practice. This will be recorded systematically for the first time in the project and serve as a reference dimension for the design of the drivetrains. The installation space of the vehicles must correspond as far as possible to the current diesel buses/coaches. In addition to their range, maintaining passenger capacity, including the additional payload for luggage, are an important prerequisite for the success of e-coaches. Beside the drivetrain and battery technology, project partners are playing an important role in aerodynamics and lightweight construction.
The profitability of the resulting vehicle concepts will also be assessed from the operator’s perspective and taken into account in the concept definition. The objective is to identify cost-efficient concepts for individual vehicles and entire fleets of electrically powered coaches for the various operating profiles.
Test drives on real customer cycles will also form the basis for the further development of the drivetrains up to series maturity.
Daimler Buses is the coordinator of the publicly funded project. Project partners are the Karlsruhe Institute for Technology KIT (ITIV – Institute for Information Technology); the University of Mannheim (MISES – Mannheim Institute for Sustainable Energy Studies); the Technical University of Kaiserslautern (iMAD – Institute for Mechanical and Automotive Design and SAM – Institute of Fluid Mechanics and Fluid Flow Machines) and operator Flix SE with its green Flix long-distance coaches.
Flix SE will contribute its distinctive competence in planning and controlling the world’s largest long-distance coach network to the project. This is intended to make sure that even more environmentally friendly alternatives will be available for long-distance coach operation in the future and that these meet the technical requirements of the companies. The operations of the current vehicle fleet will thus form the data basis for deriving representative driving cycles for long-distance routes. Flix will evaluate the operational characteristics of the projected solutions at an early stage. This means that an assessment can be made at the midpoint of the project about the feasibility of switching to battery electric coaches. Flix will also be involved in the validation of the demonstration vehicles under real operating conditions. Flix has specified the use of alternative drives as an important part of its strategy toward further CO2 reduction. Accordingly, the company has a great deal of interest in coaches that can be deployed under the very challenging operating conditions typical of Flix.
The Institute for Mechanical and Automotive Design (iMAD) and the Institute for Fluid Mechanics and Fluid Flow Machines (SAM) of the Technical University of Kaiserslautern each possess specific expert knowledge in the disciplines of lightweight construction and aerodynamics. In the development of innovative solutions, the researchers will use modern simulation methods and will be able to fall back on the corresponding test facilities. Since both theme fields have a significant influence on energy consumption, they are of particular importance in the context of the electrification of coaches.
The KIT’s “Institute for Information Technology” (ITIV) will contribute its outstanding expert knowledge in handling large amounts of data to the analysis of operating conditions and the development of a smart operating strategy. In addition to minimizing energy requirements, factors such as optimal load distribution of the drivetrain and the efficient use of recuperation must also be taken into account using artificial intelligence methods.
Based at the University of Mannheim, the Mannheim Institute for Sustainable Energy Studies (MISES) will carry out the profitability analysis from the perspective of the operators and thus make an important contribution to the concept definition. This will ensure the marketability of coaches with battery-electric drivetrains right from the development phase.
The close cooperation of the participating, highly competent project partners – supported by public authorities – will ensure fast and practical development on the road to becoming a fully electric coach.