## Consortium including Volvo Car Group completes successful study of EV wireless charging

##### 24 October 2013
 Inductive battery charging components. Click to enlarge.

A consortium of companies, including Volvo Car Group, Bombardier Transportation and the coachbuilder Van Hool, has successfully completed a 3-year research project studying the possibilities of inductive charging for electric vehicles. (Earlier post.) The results show that this technology for transferring energy via an electromagnetic field has “great potential,” according to Volvo.

The inductive charging project was initiated by Flanders’ Drive, a research and test center for the automotive industry in the Flanders region in Belgium and was partly funded by the Flemish government. Volvo Cars supplied the car for the inductive charging project: a Volvo C30 Electric with a power output of 89 kW (120 hp) and a 24 kWh battery pack.

Inductive charging uses an electromagnetic field instead of a cord to transfer energy between two objects. An induction coil creates an alternating electromagnetic field from a charging base station. A second induction coil in the portable device picks up power from the electromagnetic field and converts it back into an electrical energy that charges the battery.

The Flanders Drive project explored inductive charging in both a passenger car as well as a transit bus. For the passenger car aspect, the consortium used two different inductive charging systems: a faster charging 20 kW, 380 Vac 3-phase system from Bombardier (which also supplied a higher powered unit for the bus); and a slower charging 3.8 kW 240 Vac single-phase unit from Inverto.

The tests demonstrated that our Volvo C30 Electric can be fully charged without a power cable in approximately 2.5 hours [at 20 kW]. In parallel with this, we have also conducted research into slow and regular charging together with Inverto, which was also a partner in the project.

With inductive charging, you simply position the car over a charging device and charging starts automatically. We believe that this is one of the factors that can increase the customer’s acceptance of electrified vehicles. Inductive charging has great potential. Cordless technology is a comfortable and effective way to conveniently transfer energy. The study also indicates that it is safe. There is not yet any common standard for inductive charging. We will continue our research and evaluate the feasibility of the technology in our hybrid and electric car projects.

—Lennart Stegland, Vice President, Electric Propulsion System at Volvo Car Group

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### Comments

Of course nits the efficiency that is of interest, maybe that is why the 'potential' is so great.

With 'free' renewable wind/solar and even cheaper - too cheap to meter nuclear energy just around the corner that will be too cheap to meter, I can see that the dream of a cashless society will be realised almost immediately if not sooner.
Even Merrill Lynch and Lehman bro's couldn't achieve such results.

So, passed as perfectly safe by Volvo, which should serve to convince the most rabid spreaders of FUD, if the fact that inductively charged buses have been running for ten years in some Italian cities without signs of heaps of dead Italians in the streets.

I said this would be popular years ago, the self appointed "wise ones" said NO.

Wait a minute it took 2.5 hours to charge a 24 kW Battery at 20 kW, that is only 48% efficiency, that is horrible!

At one level, it's a question of what people are willing to pay for.  Wires are cheap and the inconvenience is negligible.

At another level, it's a question of the opportunities foregone.  Inductive charging is one-way and cannot support V2G.  The loss of value-added services may make an emphasis on wireless charging ill-advised.

@EP:
Driving a bus, a taxi or a delivery vehicle, all early target markets for inductive charging, plugging ins is far from a negligible inconvenience.
In crowded streets and pavements of European and Asian cities there is also simply nowhere to put sidewalk chargers, and their trailing wires are hazardous.
Vandalism is also held in check, and durability should be much greater.
All in all, the advantages are considerable, and far from limited to the time it takes to plug in.

Wireless charging is a bit less efficient than plugging in. One company reports >94% efficiency so the energy loss is not great. Many people are likely to be willing to pay a slightly higher electricity bill in order to avoid the plug/unplug routine.

35 miles avg. driving x 0.3 kWh/mile = 10.5 kWh/day.

13c/kWh avg. electricity price x 10.5 kWh = $1.37. 10% (high loss estimate) =$0.14 per day.

Think of those nasty weather days and how nice it would be to simply park and go. Not having to deal with cords and plugs.

The cost of embedding inductive charges or installing curbside chargers could be very similar. Especially when considering the maintenance/vandalism costs.

The bus would be better off with a Busbaar, and the taxi with a Supercharger.  For anti-vandalism and space saving, the wired bits can be put on overhead swing-arms and possibly integrated with existing light poles.  A Bluetooth or smart phone command would swing the arm down and bring the connector within reach, and the vehicle might have auto-eject for the connector after which it would swing back up out of harm's way until called upon again.

This really speaks better to the needs of taxis, which have to be on the go all the time to make money.  Being able to suck down power at the rate of 80 kW would allow something like a Tesla Model X to be a premier NYC taxi; just a few minutes at a taxi stand every few hours would be enough to keep one going 24/7.  The downtime for inductive charging would be far greater.

The argument against wireless charging is very similar to what we had against automatic transmissions.

Both technology cost more than the cable/plug and the gear shift. In both cases higher cost is offset by higher user acceptance.

Very soon, many will accept to pay more for wireless charging EVs than equivalent ICEVs for similar reasons. Not having to 'gas up' at $4 to$8/gal or 'plug it in' is going to be a great joy for many.

Plugging in is so easy and simple, only lazy people would find it onerous enough to spend many hundreds for an inductive charger.  You are getting in and out of the car anyway, and the connector is right there.  It is literally 2 seconds.

'For anti-vandalism and space saving, the wired bits can be put on overhead swing-arms and possibly integrated with existing light poles. A Bluetooth or smart phone command would swing the arm down and bring the connector within reach, and the vehicle might have auto-eject for the connector after which it would swing back up out of harm's way until called upon again.'

On British and European city streets, where around 50% of cars are parked overnight?
I don't think so.
Check out google street view for just about any British or European central area to see how impractical this is, if battery cars catch on.

There is certainly no way it would work in the area I live, for instance.

As for cost, we are still in the early prototype stage, and costs should be comparable to wired charging stations as they are further developed.

If your parking is that crowded, are you going to be able to achieve the necessary alignment between the charger pad and the vehicle's pickup coil?  Wires either reach or they don't.

Parking and alignment to wireless charger will be done automatically by future EVs.

Many Fords could do it with minor software changes. It would also avoid damages to many cars from bad drivers who do not master parking techniques well enough.

This type of automation is mature low cost technology.

@EP:
Likely the road will be marked into charging sections, and the more EVs there are, the more people will align with the chargers, making it easier for the next guy to park in the right place.

Seriously, most places there is simply no room for the street furniture involved in other forms of charging.

Have a look on Streetview at the streets in Bristol, England where I live.
And that is more typical of most cities around the world than streets in the US are.

Both sides of the street are solid with parked cars, with only a narrow road in between and narrow pavements in many places.

Davemart, how about a hyperlink so I can see exactly what you mean?  And the "division into charging sections" eliminates the rationale for tight-squeezing vehicles like the Smart Car.

Perhaps it's not practical in old-world cities.  But in the USA, there's usually space for light poles, traffic and parking signs, and often parking meters (not to mention trees).  Anyplace something is stuck up and out of the pavement, there's potential to put a support pole for overhead hardware.  If it doesn't work outside of North America, it doesn't need to work anywhere else; other places can find their own solutions, since they are separate markets.  Some even put the steering wheel on the wrong side! ;)

Wireless chargers made in the hundreds of millions are likely to become fairly cheap.

Installing them in all the places we park is likely to be done over time. When it's time to resurface a street/parking lot all the parking spots will be wired.

With automatic parking and the ability to have the car's receiver lowered so that it is very close proximately to sending unit should decrease the energy loss to well under 5%.

Electricity is already cheap and on the way to being cheaper. 5% more than a two cents per mile is not really money. A dollar a month.

Cars will be able to communicate with the sending unit, relaying the amount of charge desired and where to send the bill.

The convenience will be so great and the cost margin so low that my guess is we'll go to large scale wireless charging.

Even the aesthetic gain of not having charging units adding clutter to our streets will be valued by some.

Assuming we get higher capacity batteries and EVs become our future I can see how convenient charging is likely to become. No more stopping at gas stations. Your car should be charged whenever you get in.

Your car will know your daily driving pattern. If you are going further you'll punch in/speak your destination and your car/GPS will take over and keep you informed as to when and where to stop for a recharge. You'll probably be able to dial in your food preferences/need for a dog walk/whatever so that your charge point fits your specific needs.

@EP:
It is North America which is the exception, not Europe and 'the Old World'
Asian cities will be just as cramped, probably even more so.
Electric cars depend on mass production, and wireless chargers can serve far more of the market than wired.
Even in the US a very large number of cars live beside the road, and wireless would be far more convenient for them, if not essential due to most places having more room.

Smart cars which can get a couple into a single space are a tiny minority, although parking bays in shops etc are much smaller than in the US.

Posting links to google street view has never worked for me, but here goes:
https://maps.google.co.uk/maps?q=a&hl=en

If that doesn't work, it is 'Sandbach Road, Bristol'

That road is not the exception, and if you have a wander in Street view you will see that there simply is not room for the chargers needed unless they are under the road.

I note that my link ended up showing Bolivia! :-)

Normal progress will prevail and USA will (eventually) join the Metric system like 99+% of the countries of the world.

Eventually, wireless charging will be the choice of the majority because it makes so much common sense, like automatic transmissions, automatic washing machines, automatic car wash etc etc do.

Another possibility would be to integrate wireless charging at every city block corner equipped with traffic lights so EVs stopped at those traffic lights would get a quick charge. Of course the wireless chargers would identify every EVs and charge the owners credit card for the energy used.

Reality check: People plug in their cell phones, laptop PC, tablet PC, cordless drills, etc. all the time. What percentage of them use inductive charging?

Let's guess at some reasons why inductive charging is not widely used:
1. Added weight and bulk to the mini-appliances.
2. Added cost.
3. Electromagnetic inteference?
4. Noise?
5. Lower efficiency.

Now then, placing induction coils under the pavement and burying wires to them is going to be expensive. Placing extension cords flushed with the ground surface is a heck of a lot cheaper. I don't see why cars parked on the roadside can't be charged with extension cords plugged into sockets outside the house.

Why adding more to the infrastructure cost of PEV's when the beauty of using PEV's is inherent in taking advantage of existing grid infrastructure that is already paid for? Along the same logic, why adding to the infrastructure cost of BEV's by building fast-charging stations for PEV's, when PHEV's can take advantage of existing liquid fuel fillup infrastructure to the tune of 22MW of speed! There is no way that a BEV fast-charging station can match that kind of speed!

It is North America which is the exception, not Europe and 'the Old World'

North America has more vehicles per capita than Europe and, given today's building and transport patterns, this will continue.  And as I said, the solution which works for North America need not work elsewhere to be A Very Good Thing.

wireless chargers can serve far more of the market than wired.

How well do wireless chargers work under historic cobblestones?  Oh, right... they don't.

Even in the US a very large number of cars live beside the road, and wireless would be far more convenient for them

Wireless would require scheduling a re-paving operation, laying out defined parking spaces with clearly marked induction pads, putting in all the hardware (including lots of electronics), and either marking the failed parts as unavailable or tearing pavements up and replacing them promptly when things quit.  Using lots of electronics means replacing lots of electronics when the inevitable failures occur.

Wires can be strung overhead between streetlight poles and/or tunneled below grade between parking meters, and failed flexible sections can be replaced in a few minutes by an electrician.  Very little in the way of electronics is required.  The major issue I see at the moment is that the default charging connection is on the left side of North American vehicles, which is the side facing the road rather than the curb (kerb to you).  This puts it in the wrong place for vehicles not parked in a private parking space.

You should test links before posting them.

HarveyD:  Wireless charging makes no sense for high-power charging or V2G.  The loss of those two values must be added to the cost of wireless hardware to get the true cost.

@EP:
'How well do wireless chargers work under historic cobblestones? Oh, right... they don't.'

What percentage of the streets of 'Olde Europe' do you imagine are covered with cobblestones?
Or the streets of Tokyo, even more pushed for space?

Did you actually look at the link I provided to the streets around here?

If so, where in the world do you imagine that charging units could go?

I would also be interested in your source for the notion that they won't work through cobblestones, which are anyway in the rare places they still exist almost exclusively in pedestrian precincts.

'Wireless would require scheduling a re-paving operation, laying out defined parking spaces with clearly marked induction pads, putting in all the hardware (including lots of electronics), and either marking the failed parts as unavailable or tearing pavements up and replacing them promptly when things quit. Using lots of electronics means replacing lots of electronics when the inevitable failures occur.'

Or they could simply be put in when the road was scheduled for re-surfacing anyway, as it won't happen overnight.

I don't know why you think there are 'lots of electronics' in under the road pads, but not in streetside chargers.

Under the road they may be more difficult to repair, but they are a heck of a lot less likely to need it.

If you think that they are going to allow wires simply to be strung up overhead in Europe, you are greatly mistaken.

Again, have a look at the link I gave, and get serious about thinking about how it would be possible to charge the vast numbers of cars there.

'Wireless charging makes no sense for high-power charging or V2G.'

Based on what assumptions and studies?
I don't know about V2G, but high power inductive charging is up and running:

http://venturebeat.com/2013/10/10/utah-based-wave-nabs-1-4m-to-bring-wireless-electric-buses-to-a-dozen-cities-exclusive/

From memory I think they give the figures in the video, but in any case it gives a pretty good belt of power.

Charging through a wire is OK for folk with garages, which presumably is almost everyone with an electric vehicle today, but utterly impractical in most places in the world, and difficult for road side cars even where possible.

I won't even get into the notion of running wires across the pavement - is there a lawyer in the house?

If battery electric cars are going to become the predominant for of transport, then the only way it can be made to work is by using inductive charging.

Perhaps wired charging could remain dominant in the US, but economies of scale, as well as convenience, likely mean that even in regions like the US inductive will win out.

Notions that because most people don't inductively charge their toothbrush, they won't charge their cars that way, ignores the fact that most people don't take their toothbrush out into the road to charge it.

Hey guys, you are quibbling over nits IMHO. I want an above ground inductive charger in my garage where I have to locate my car sensibly anyhow. And the cost of having a cord and connection available in the car for a remote charger is minor. I would want the cord scheme for V2G anyhow, and given a PHEV, an occasional boost on a trip. They are not mutually exclusive. As time moves on both V2G and inductive chargers will find there place in the diverse marketplace anyhow. I've always wondered how efficient the wireless charge could be given a required air gap, and now I have a data point. But a garage/driveway is fairly controlled and repeatable, and would cover a large percentage of charge needs for most personal vehicles.

where in the world do you imagine that charging units could go?

I see light poles rooted on the outside of the sidewalks.  Poles like that could support overhead swing-arms with charging cables.

If you were using inductive chargers, where would you put inverter electronics?  How would you cool it?  You're talking kiosk-size installations.  An overhead swing-arm like a knuckle-boom crane seems much easier to site to me; it takes up no space at ground level, would be well above head level except for the business end and could retract on gas pistons when not in use.

I don't know why you think there are 'lots of electronics' in under the road pads, but not in streetside chargers.

Because there is essentially nothing to a J1772-style "charger" except a 12-volt bipolar power supply, a ground-fault sensor, a power relay and a microcontroller for smarts.  You could fit most of it into the connector.  It's basically a smart power cord.

'Wireless charging makes no sense for high-power charging or V2G.'

Based on what assumptions and studies?

Based on what electronics cost and the doubled cost of making an inductive system bidirectional.  It's a whole lot of expense to eliminate a couple of wires and a connector, and there are worthwhile things you lose the ability to do.

The South Korean bus system that uses inductive charging has placed their senders 8" under the surface of the pavement.

Using EVs as grid storage is likely not as important as having EVs available as a dispatchable load. If we end up with most parked EVs available for grid-controlled charging then we can 'overbuild' wind and solar, send over supply peak to EVs and avoid needing to store.

Direct usage will always be cheaper that storage. And grid storage batteries will likely be much cheaper than EV batteries because there is no weight/size penalty.

Rapid/Level 3/long trip charging may be best done with cable and plug. But since 90%+ of all charging can be done at slower rates we needn't worry if inductive charging is somewhat limited.

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