Steadily rising gas prices, an increasing desire for detachment from the turmoil on international raw materials markets and the obligation to save both the local environment and the global climate: these are the main reasons for communities, public transport providers and transport associations to develop new concepts for the operation of electric buses.
Trams and trolley buses are mature, established technologies. However, they can only be operated economically under conditions of high transport demand and their implementation is impeded by high infrastructure costs. In addition, reservations towards installing the necessary catenaries exist in many cities.
In many cases, electric buses equipped with batteries are a viable alternative to trolley buses. Due to the insufficient capacity of current battery storage technologies, however, the range they can achieve between two recharging processes is still rather limited. But if a bus route features the right relation between driving time and distance, on the one hand, and time spent at bus stops and turnaround areas, on the other hand, the on-board energy storage units can be appropriately recharged during the day so that longer total distances can be covered. This charging routine is often referred to as »opportunity charging«. The basic requirement for the application of opportunity charging is the disposability of fast chargeable battery buses that are able to take in a sufficient amount of electric energy in the available time.
The key technologies necessary for battery buses with fast charging capacity were developed within the »SEB - Schnellladesysteme für Elektrobusse im ÖPNV« project (Fast Charging Systems for Electric Buses in Public Transport) funded by the German Federal Ministry of Education and Research. Within EDDA-Bus the sub-project, the Fraunhofer IVI and its partners developed feasible concepts, designed the necessary equipment and brought the complete system to series readiness.