Each vehicle will be equipped with enormous 130kw/h batteries – giving them a
100-mile range and a capacity equivalent to around six Nissan Leafs.
The buses will receive regular top-up charges throughout the day from the
three wireless charging points installed along the routes.
Charge pads on the underside of each bus will sync wirelessly with pads
installed under the road, in a process known as induction charging. Drivers will
park over the pads for their 10-minute break, replenishing two thirds of the
electricity used to cover the 12.5-mile route without interrupting the
timetable.
The consortium of companies behind the scheme – which include bus
manufacturer Wrightbus, wireless charging firm Arup, bus operator Arriva and
Milton Keynes Council – believe that the switch from diesel to electric will cut
tailpipe emissions by around 500
tonnes every year.
Running costs will also be slashed, as annual fuel costs for a diesel bus are
around £23,000 per year compared to an estimated £10,000 for an electric one.
And maintenance costs will be lower, too.
Colin Bennett on 04 Aug 15"Centuries ago, Nikola Tesla envisioned and pioneered the concept of wirelessly transmitting power over long distances through the Earth's ionosphere. In the recent past, wireless energy transfer has occurred by way of an electromagnetic (EM) field set to a certain frequency level. While transmission efficiency over longer distances is attained to an extent by this method, it becomes increasingly difficult when complicated pointing and tracking mechanisms are mandatory to maintain the right wavelength between the transmitter and the receiver. Another drawback to this approach is that any object that falls between the transmitter and the receiver impedes the beam, thus interrupting power transmission to a potentially harmful degree if the power level goes beyond a certain threshold point. Even though microwave frequencies could prove effective to transmit power over long distances through a radiated EM field, the aforementioned caveats still apply. The other possible way to wirelessly transmit power is by non-radiative fields. For instance, a transformer operates by magnetic induction drawing similarities to wireless power transfer. Energy transfer in a transformer happens from the primary coil to a secondary coil in the absence of a direct electrical connection. The same approach can be seen in inductive chargers found in electric toothbrushes, for example. However, for this functionality to operate smoothly, primary and secondary coils must be positioned in close proximity to one another."