Electric buses with wireless charging set for UK runs in Milton Keynes

Jan 11, 2014 by Nancy Owano weblog
Credit: ARUP

(Phys.org) —The UK can celebrate the launch of its first electric bus routes, to swing into operation this month in Milton Keynes, where eight electric buses will be running, taking over a busy "Number 7" 15-mile route, and covering two suburbs of Wolverton and Bletchley. These buses are the first of their kind in the UK. The new timetable will be implemented later this month. The electric bus fleet is operating as a five-year, multi-partner trial program. Among the participants are the European division of Japanese company Mitsui and design engineering consultancy Arup According to Arup, the data collected in the Milton Keynes trial could be used to kick-start electric bus projects in other towns and cities worldwide

The launch this month is a test to see if these electric buses, which are to run a continuous, 17-hour service, can match their diesel counterparts in performance under busy real-world conditions. The program is to be closely monitored in order that the program's participants can assess if these buses' technical and commercial viability meet expectations.

"If we can demonstrate true parity with diesel buses during this trial, we'll have reached a tipping point for low-carbon transport – we'll have proved it can be cost-effective as well as green," said Professor John Miles of Cambridge University, department of engineering and Arup consultant.

The technology at play involves where the batteries get their charge from underground induction coils positioned at the start and end of a bus driver's route. Charging plates are set into the road, for transferring power to the receiving plates under the bus.

A report in IEEE Spectrum further explains what takes place: "Inductive occurs when an electric current run through a coil, creates a magnetic field, which, in turn, induces current in any nearby conducting loops. When a bus stops at either of the charging stations, its on-board induction loops, lowered to four centimeters above ground, enter the magnetic field. The resulting current tops up its batteries enough to ensure it has enough energy to make it to the other end of the route and its next charge up."

After a night charging at a depot, where the bus will get a full charge from its source, a bus will be able to replenish its batteries during its daily runs throughout the day with a ten-minute charge from the plates which are buried in the road. Two charging points can service all eight buses, which will charge in the time scheduled for driver breaks.

The inductive charging approach has the advantage of allowing the buses to run with smaller lighter batteries, with less dependence on onboard energy storage.

Explore further: San Francisco to charge fee for tech company buses

Related Stories

New bus system tops off batteries in just 15 seconds

Jun 04, 2013

(Phys.org) —A new type of battery bus system being tested in Switzerland is able to operate continually by making use of flash-charging stations. Called Trolleybus Optimisation Systeme Alimentation (TOSA), ...

Hybrid buses improve air quality in Hanoi

Jul 25, 2013

Siemens and the Vietnam Motors Industry Corporation (Vinamotor) are launching the first hybrid bus with a combined electric/diesel drive in Hanoi. The project is the first of its kind in Vietnam. The vehicle ...

Recommended for you

Fuel cells to connect our smartphones to the outside world

3 hours ago

The potential of hydrogen and fuel cell applications goes way beyond the development of green cars. The FCPOWEREDRBS team is determined to prove this with a Fuel Cell technology to power off-grid telecom stations. They believe ...

The state of shale

Dec 19, 2014

University of Pittsburgh researchers have shared their findings from three studies related to shale gas in a recent special issue of the journal Energy Technology, edited by Götz Veser, the Nickolas A. DeCecco Professor of Che ...

User comments : 17

Adjust slider to filter visible comments by rank

Display comments: newest first

italba
1 / 5 (1) Jan 11, 2014
Why wireless? Can't they just put two electric contacts on the roof, as in trolley buses?
BSD
5 / 5 (2) Jan 11, 2014
Why wireless? Can't they just put two electric contacts on the roof, as in trolley buses?

This system is more reliable, the bus just sits over the inductor and charges, much like a shaver does when it is put on it's stand after use. If contacts were used, they would become dirty and spark when ever the bus parks under them. The contacts would eventually burn out and need replacing. Magnetic induction requires no contact at all.
El_Nose
not rated yet Jan 11, 2014
don;t get me wrong i am for this -- but italba has a point -- having the driver plug it in would save money and power. Inductive charging is nice but it is very wasteful as it just radiates energy away.

Also the mechanism for lowering and raising the receiver to be close enough to charge is going to have a tendancy for mechanical failure as well - say 10 times a day for 5 years -- the only other mechanical thing thing being used more on the bus will be the doors.
antialias_physorg
5 / 5 (3) Jan 11, 2014
Can't they just put two electric contacts on the roof, as in trolley buses?

That is mechanically complex (read: maintenance intensive) and also prone to failure (read: can be pranked/vandalized easily) as well as very sensitive to positioning. Whereas the inductive system is pretty much 'fire and forget'.

Inductive charging is nice but it is very wasteful as it just radiates energy away.

With the low distance (4cm) and the large coil diameter. less than you might think.
JRi
not rated yet Jan 11, 2014
I wonder what kind of Teslas they are talking inside the bu while charging. Pacemakers may go nuts.
Gavilan
not rated yet Jan 11, 2014
What is the throughput efficiency from power plant fuel source to propulsion?

How does this compare to a constant output ICE /electric Hybrid?

If the energy source is electricity from a coal fired or nuclear plant how can the process be considered "green?"
antialias_physorg
5 / 5 (2) Jan 11, 2014
I wonder what kind of Teslas they are talking inside the bu while charging. Pacemakers may go nuts.

None at all as the field does not extend beyond the coils. It's like induction cooking ranges. Whether it's harmful to your pacemaker (or your smartphone) is alos a matter of frequency.

If the energy source is electricity from a coal fired or nuclear plant how can the process be considered "green?"

It can be considered green as it does not produce any emissions/waste at the place you're using the energy - which gives you the option to have it fed by green power plants (something other types of vehicles do not give you)

The point being: If you don't have systems that cannot make use of 'green' energy then switching over makes sense. So you have to install stuff that makes it possible for such a demand to exist and stop to bitch and moan about current sources of energy. .
italba
not rated yet Jan 11, 2014
There are thousands of trolleybuses out there and they don't seems to need such a big maintenance. And, in this case, contacts doesn't need to be mantained while running, they can be much simpler. The charging station are planned at the start and end point of the route, easy to survey. Any way I wonder who would be so stupid to try vandalize two live high tension electrical wires some 5 meters high.
Eikka
not rated yet Jan 11, 2014
. The contacts would eventually burn out and need replacing. Magnetic induction requires no contact at all.


With the low distance (4cm) and the large coil diameter. less than you might think.


Over the lifetime of the vehicle, the efficiency of the mechanical connection might still win. If you lose just 5% more power in the induction coil, that's going to be thousands of kilowatt-hours per car per year lost, which will be hundreds of pounds per car. Surely that is more expensive than replacing a strip of metal on top of a pantograph.

And the positioning for a pantograph system isn't that critical. The Norwegians already have a 400 kW charging system that has two pantographs sideways, one at either end of the bus, and you drive it under two beams that travel lengthwise over the stop. They're large enough that being a couple meters or degrees off doesn't matter.

christophe_galland1
not rated yet Jan 12, 2014
"we'll have reached a tipping point for low-carbon transport"

This is a useless and controversial statement - ammunition for pointless arguments over global warming again. Of course this all depends how the electricity is generated in the first place.

Why not emphasizing the REAL BENEFITS of electric, public transportation? Namely a large improvement in the quality of life in the cities. Less noise. Less air pollution. Less traffic (1 bus = 10 to 40 cars). More friendly roads for pedestrians and cyclists. Etc.

This is by focusing on immediate benefits for citizens, and not on uncertain future development (even if extremely likely), that change will happen.
Mike_Massen
not rated yet Jan 12, 2014
Any sort of induction methods in transit or limited to regions of approaching, stopping & leaving could etc but, all that is needed is clever charge when stationary. ie do dah maths :-)

Eg. It is SO simple to arrange a pair of 'contacts' & apart enough (one each end of bus):-

a. Enabled via a signal from the bus when it is in position (& via servo).
easy RF security to enable switchgear underneath shrouded contacts
b. Mating contacts descend from bus, appropriate interlocks engage
c. Sizable charge dumped from beneath road supercaps into bus' supercaps
d. System on bus feeds power to batteries &/+r uses supercaps directly

When no bus etc, System at Bus Stop, charges Bus Stop supercaps *appropriately* so as not to cause brownouts

Road contacts have appropriate shrouds/coverages to match bus contact exposure, shrouds
& coverage so as to avoid accessible areas when on & also when not powered.

What could be simpler ?

Now, could the above be augmented - any ideas ?
Mike_Massen
not rated yet Jan 12, 2014
Contd..
I am since advised to inform.

By the way, should have mentioned; the above, along with interlocks, electrical, electronic & mechanical designs & the various sequences of operation under normal & exceptional conditions is covered in considerable depth within Australian Provisional Patent & supporting documentation lodged with some government departments & a couple of legal firms which clearly & unequivocally confirm precedence a significant period of time prior to the post I made today some 30 minutes ago - ie The earlier Date(s) at which these were created, delivered & accepted.

In respect of augmentation, one might first wish to consider various assumptions & how a change to public access to buses re timing and infrastructure re bus stop location may well further advance aspects and feed into public cars on those same systems & how they can be managed in conjunction without there being any sort of interference etc...

Still open to discussion, no problems there :-)
Bob_Wallace
5 / 5 (1) Jan 12, 2014
South Korea is running a couple of buses using "on the go" inductive charging.

Sending units are buried 8" under the road surface. About 10% of the route is wired with senders. 85% efficient.
EnricM
not rated yet Jan 13, 2014
Why wireless? Can't they just put two electric contacts on the roof, as in trolley buses?

God question.
I suppose that whole infrastructure of the cabling would be much more expensive
Bob_Wallace
not rated yet Jan 13, 2014
Overhead wires for the entire route is expensive and not exactly attractive. Plus they are route-limited. For example, the bus can't drive around a double parked vehicle or take a detour when road repair is being done.

There's another system being tested where buses 'hook up' via roof mounted contacts when they stop at some bus stops to load/unload passengers. With ultracapacitors they can grab a bunch of miles in a hurry.

The in-road charging is very interesting because it gives us a way to charge EVs on long trips without having to stop at a charging station. EVs could carry smaller, lighter, less expensive battery packs - enough to get them around town - and then grab charge from the road when traveling between towns.
hangman04
not rated yet Jan 14, 2014
"Overhead wires for the entire route is expensive and not exactly attractive. Plus they are route-limited. For example, the bus can't drive around a double parked vehicle or take a detour when road repair is being done."

Don't forget they still have batteries meaning some basic autonomy...
Bob_Wallace
not rated yet Jan 14, 2014
New York City just released data for it's first two months of using a BYD battery powered bus. The bus has a range of 140–155 miles on a single charge, is expected to retain 80% of its battery capacity after 12 years, and takes 3-4 hours to recharge at night.

Operating costs were $0.20 to $0.30 per mile as opposed to $1.30 per mile an equivalent diesel or natural gas bus costs in New York City.

http://cleantechn...9k5Qw.99

Maybe the answer is just to use enough batteries.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.