Richard Whitfield
Wide scale adoption of electrically powered buses is a “no brainer”; the only question is when. Electric buses are significantly quieter and produce virtually no roadside pollution. Depending on how the electricity is generated, they can substantially reduce overall pollution, which is a political “hot potato” in China and other parts of Asia.
Moreover, electric buses are much simpler mechanically – with little need for gearboxes or engine cooling systems or fuel distribution systems and much lower “wear and tear” on their braking systems – so they have a much lower maintenance burden. And, again, depending on how the electricity is generated, electric buses have significantly lower fuel costs than conventional diesel powered buses.
The big stumbling block with electric buses is having enough battery capacity to run a full operating shift. The batteries are very expensive, and even lithium batteries weigh a lot compared to diesel (which has a much higher energy density). There are also reasonable concerns about plugging buses into the electricity system overnight to recharge their batteries – it takes the bus out of service for a relatively large proportion of the day and it is very easy for drivers to forget to unplug before driving away in their bus (and damaging the plug and bus) and the plugs and cables are walking hazards. Another issue with the plugs is that they involve high voltages and currents and often only registered technicians are permitted to connect them, which can significantly increase operating costs.
These problems largely disappear if you use wireless recharging for the bus. This involves embedding an induction loop in the roadway underneath a bus stop. When a bus stops over the in-ground loop a current is put through it which induces a secondary current in a second induction loop located on the corresponding underside of the bus. The secondary current thus recharges the battery.
Placing recharging induction loops in the roadway at each end of a bus’s route means that the bus can be regularly recharged throughout its working day. Thus, it only needs enough battery capacity to last a few route legs and not a whole day of operations. Moreover, there is no need for overnight recharging so that the operating hours of each bus can be greatly extended. And there are no cables and plugs anywhere.
Several companies are working on wireless recharging systems for buses and other vehicles. It is already possible to buy home vehicle induction recharging kits for private cars in the USA that are priced at under USD3,000/unit, including installation. Other companies have licensed their wireless recharging technologies to Toyota, TDK and Delphi, and major car makers (including Audi, BMW, Daimler, Ford, Jaguar, Mercedes-Benz and Volvo) are expected to release “wireless recharging ready” models soon, according to The Economist.
Bus Line Route 7 in Milton Keynes in the UK is already being served by electric buses that pause for 2-4 minutes over recharging pads at the end of each route leg. The bus operating company estimates that it is saving USD0.50/kilometre using these buses when compared to the previous diesel powered buses. Wirelessly recharged buses are also running in Mannheim, Utrecht, Genoa, Turin, Salt Lake City and the Californian cities of Lancaster, Long Beach, Monterey, Palmdale and Walnut Creek. Los Angeles is expected to soon join the list.
I would really like to see the first wireless recharged electric buses in Asia operating in Macau, preferably within the next year. Why not? Public buses would be best, but casino shuttle buses would be a good second choice.
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