Electric buses are coming back

FRANK BEETON reports on important bus news from overseas.

In recent years, news releases detailing the development or sale of new buses using varying degrees of electric traction have become increasingly common. This trend has gathered momentum as hybrid driveline vehicles, utilising varying combinations of internal combustion engines and electric motors, have entered the market, with some of the newly developed technology being equally applicable to both hybrid, and all-electric propulsion systems.

However, electric traction in road passenger vehicles is not new, having been pioneered in tram operation during the 19th century, and popularised by the trolleybuses that were commonplace in South African cities up to 1986, when the last network was closed in Johannesburg.

Trolleybuses fell out of favour in many parts of the world for a number of reasons; most of which related to the overhead power supply and lack of operational flexibility, but recent technical advances are making it extremely likely that more modern equivalents will become increasingly familiar in the years ahead.

Last month’s article on Volvo’s plug-in hybrid bus, with its overhead current collection gear for use at terminals, indicates one way forward. However, an even more radical solution, developed by Canadian transport specialist Bombardier, provides an almost invisible infrastructure to keep electric buses, trams and trains on the move. Named Primove, this system uses wireless and plugless inductive power transfer from underground charging points placed at strategic stops (e.g. bus stops, stations) to the vehicle positioned overhead.

The technology employs primary coils, placed under the road surface, which create magnetic fields, and secondary coils in the vehicles which, on entering the magnetic fields, receive the current and replenish the on-board batteries.

Primove demonstration systems are already operational in Germany, at Augsburg (tram), and Braunschweig (bus), while a new bus and service-van system has just been announced in Mannheim. In Lommel, Belgium, a 125 m section of public road has been fitted out with Primove charging equipment to work with a suitably-equipped bus and passenger car.

The Primove system seems to effectively address all the earlier objections to electric bus operation, and it will be interesting to see how much commercial success it achieves. While there would be some logic in getting rid of heavy on-vehicle battery current storage, its retention will ensure that mobility is still possible in the event of short-term power grid interruption, and this could even be extended for longer periods by the use a standby diesel or gas engine.

Should the regular use of electric cars and delivery vans grow to substantial proportions, there would be a strong argument in favour of adopting this, or a similar system, more widely for light vehicles, such as delivery vans and taxis, as well as buses and trams.