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TOSA : The first large capacity electric bus

ABB has developed a technology capable of supplying the world’s first 100% electric high-capacity bus: TOSA, which in French stands for “Transport avec Optimization du Système d’Alimentation” (Transport with Optimized Power Supply System). This bus can be recharged at certain bus stops in only 15 seconds, whilst ascent & descent of the passengers. This solution, for high-capacity urban transport lines, was developed and demonstrated in Geneva, as part of their public transport network – TPG (Transports Publics Genevois).


Detailed Solution description

Since May 2013, TOSA* has been running between the airport in Geneva and the Palexpo Exhibition Centre, as part of the TPG network. Its unique features: This bus is fully electric; its stores its energy in batteries, which are recharged whilst the bus is stationary at bus stops. The recharging operations take place during ‘hidden’ period of bus operations, at certain of the line’s bus stops whilst the passengers are getting on and off of the bus, as well as the termini.

  • At selected stops along the route, the on-board batteries are recharged in just 15 seconds at a power of 400 kW.
  • At the terminus, the batteries are fully recharged in just 3to 4 minutes. Thanks to this innovative electricity supply system, the energy can be stored in compact batteries, leaving more space for the passengers.
  • During braking and slowing, energy is recovered by the batteries, further reducing the total energy consumed by the vehicle. The system uses a retractable, laser-guided arm, fitted to the roof of the bus, which links up to rail at the stop, enabling the system to be recharged at the stop and doing away with the need for classic catenary systems. Contact is established in less than a second thanks to the automated systems, leaving a maximum of time available for recharging.

This flash recharging system and the on-board drive equipment used during the project were developed by ABB and optimized for high-frequency bus services in urban areas, transporting large numbers of passengers during peak periods. As opposed to trams and trolleybuses, very little infrastructure is required along the route, reducing both the visual pollution caused by catenary systems and the maintenance required. Zero CO² (or other) emissions, TOSA is a concrete solution to the challenge of sustainable mobility. On the 12 March 2014, the TPG and general direction of public transports, who supported ABB in the development of this solution, satisfied with the experiment, renewed their commitment to this technology by deciding to roll-out TOSA along Line 23 of their network. In early 2017 a dozen articulated TOSA buses will enter service, covering around 13km of this line.   *The acronym is also composed of the first letter of each partner of the project: TPG (Transports Publics Genevois); OPI (Office de promotion des industries & des technologies – Office for promotion of industry & technology); SIG (Services Industriels de Genève – Geneva Industrial Services) & ABB.

Launch Date

Implementation began on

Mai 2013

Solution Partners


Key figures illustrating Solution deployment and results

The partial charge technology used - charging the batteries using short-duration, high-power recharges during operations, provides the following advantages:
- reduce the quantity of batteries recycled per year and per passenger from 10 to 1kg;
- increase the number of passengers per bus by approximately 10 to 15%.
TOSA already provides a competitive edge, an edge which will only increase in the future, when comparing the system with other operating modes.
The toal cost of ownership, including all expenditure and costs relating to the acquisition and use of the TOSA project, is less than these of a trolleybus and just from 10 to 15% higher than these of a diesel bus today's prices.

The industrialization and development of production models for electrical technology will undoubtedly lead to lower prices. Diesel is becoming less interesting, both from an economic point of view and an environmental one, and transport operators are looking for innovative urban solutions without having to resort to overhead cabling, flash recharging is well positioned to dethrone hybrid and diesel vehicles and turn the corner for electro-mobility.

Performance, impact and results

Elimination of polluting emissions (CO², particles, GHG); noise levels cut in half; improved urban spaces and visual impact in cities; valorisation of renwable energies: originally hydraulic, which means transport is adaptable to solar energy as the recharging operations are carried out during the day.

The first 100% electric large-capacity bus, using flash charging technology: low energy consumption due to the optimization of the weight of the batteries and the recovery of energy whilst braking; fully automated connection systems, making contact within less than a second; major reduction in infrastructure maintenance, no overhead contact lines; totally safe energy transfer methods, the system constantly monitors safety conditions during charging operations, the rail is not powered up beside charging phases.

  • Professional contact
    Benjamin Reynaud
    ABB France
    Responsable grands comptes opérateurs de transports
  • Press Contact
    Marie-Pierre Picard
    ABB France
    Head of Communication France