TOSA tech charges up electric buses in 15 seconds
By Ben Coxworth
June 4, 2013
When you think of an electric bus, you probably either picture a vehicle that has to stay constantly connected to overhead trolley cables, or that attempts to run its entire route on one charge of its onboard batteries. In Geneva, however, they’re trying something else – a system in which an electric bus takes 15 seconds to receive an energy boost at selected stops.
Billed as “the world's first high-capacity flash charging electric bus system,” the technology was created by the Zurich-based ABB Group. The system is known as TOSA, or Trolleybus Optimisation Système Alimentation [Optimizing Power System]. Here’s how it works ...
The bus begins its route with a fully-charged battery. At every third or fourth stop, a charging mechanism on the roof of the bus engages an overhead receptacle that’s installed at the stop. The charging mechanism is mounted on a movable arm, and is able to line itself up with the receptacle using a laser guidance system. Once the two devices are coupled, the receptacle delivers a 15-second-long 400-kilowatt boost to the bus’ batteries. This takes place as passengers are getting on and off of the bus.
At the end of its route, the bus takes three to four minutes to completely top up its batteries.
Working with Geneva’s public transport company (TGP), the Office for the Promotion of Industries and Technologies, and the Geneva power utility SIG, ABB is now about to begin a pilot project in which TOSA will be tested on an articulated 135-passenger bus. That bus will be running a route from the Geneva airport to the Palexpo exhibition center, and will additionally incorporate a system that harvests the power generated by braking.
Not only does TOSA eliminate the visual clutter of trolley cables, but it also frees up buses using the technology to go anywhere in the city, as long as there are enough charger-equipped stops on their route. What's more, in the specific case of Geneva, all of the electricity used comes from hydro power – so no CO2 emissions are involved at any step of the process.
More information on the pilot project is available in the video below.
Source: ABB Group