Methodology for analyzing energy supply to electrified bus systems

Purpose and goal

This project has aimed to model the energy supply infrastructure related to the buses´ energy consumption and storage taking into account electric net capacity, topography, climate, etc. Existing bus lines, timetables and passenger loads set the boundaries of the system. A method intended for public transport authorities and operators to plan what kind of buses and charging system is most appropriate from a lowest operating and financial cost perspective has been developed and tested.

Expected results and effects

It is important to look at the total cost for the bus operation instead of searching for an optimum of isolated problems such as in the trade-off between battery capacity and charger power as an example. Results indicate that the costs for charging system and electricity connection have a low impact on the total annual operating costs for electric buses in general and especially when comparing electric bus system alternatives. The best use of the method is to use iteratively, adjusting parameters (vehicle cost, depreciation time, range, etc) to study the effect they have on the total cost.

Planned approach and implementation

The project was divided in six work packages: Coordination, Business Intelligence/Environmental Scanning/Strategic foresight, Specification and Pre-requisites, Description of Competing Technologies, Modeling and Analysis and finally Discussion and Dissemination. Throughout the project the working method has been characterized by an interactive approach. An iterative process between the work packages rather than a linear logic process has tuned the scope and focus during the course of the project.