TOSA (bus)


The Trolleybus Optimisation Système Alimentation bus, concept and test like trolleybus, flash charging system is a full large capacity urban battery electric bus system built by Carrosserie Hess and developed together with ABB Sécheron, a subsidiary of ABB.

Aim of the concept and project

The aim is to provide a zero local emission mass public transportation bus system with high passenger capacity and no overhead line.
The concept supports same operating timetable and frequency as line operated with diesel buses, trolleybuses and operating conditions of Bus Rapid Transit systems.
The following aspects have been considered to comply with a sustainable mobility approach:

Origin of name

TOSA stands for Transports Publics Genevois, Office de la Promotion Industrielle, Services Industriels de Genève and ABB, the four partners of the demonstrator project TOSA2013

The technical concept

The energy is collected along the route at some dedicated bus stops while people are disembarking and embarking. Thus, there is no impact on the timetable.
The automatic electric connection is made from the top within 1 second while the bus is stopped at the bus stop. Then charging is made at high power during the 15 seconds the door remains open. At the terminal, the battery is topped up within 3–4 minutes.

The infrastructure

According to the line profile and service, the Flash Feeding Station are distributed along the line at some intermediate bus stops. At each end of the line, the recharge is performed by the Terminal Feeding Station.
  • FFS: The Flash Feeding sub-Stations are provided with energy storage to shave the peak of power on the grid required to charge the bus at the intermediate bus stops. As power is limited by the energy storage, the sub-station is connection to the low voltage grid.
  • TFS: The Terminal Feeding Sub-Stations is used to charge the bus at the terminal.
  • DFS: The Depot Feeding Sub-Stations are used to compensate the energy required by the bus from Depot to the line of service

Demonstrator (Proof-of-Concept)

The demonstrator is in service since May 26, 2013 between Geneva Airport and Palexpo. It includes:
Partners
  • Bus operator:,
  • Project coordinator:
  • Energy supplier:
  • Technology provider:
Other partners
  • Bus manufacturer:
  • Architecture design:
  • Engineering Software:,
  • Financing:,,
  • Land: