What’s the state of wireless EV charging?

Now that there's an industry standard, automakers are starting to deploy the tech.

Read the whole story

 

[real mikeb_60]

Curious about the size of of the coil, especially on the car - whether it expects the entire space in the wheelbase, and how much weight is added.

And how it's protected. How easily can it be damaged by road debris?

Most EVs (and newer ICE vehicles) have their undersides covered in plastic panels for aerodynamics and acoustics. I'd imagine that you could embed the coil into the plastic panel and then put the control electronics deeper in a more protected position within the car. Depending on the material for the coil and whether there needs to be heat dissipation material I suspect a coil assembly molded into a plastic unit would be about as resistant to damage as anything else on the car and only a couple of hundred dollars to replace.

Just as a side note, given a recent experience with some debris in a construction zone that was unavoidable, I wish that at least some of those undercovers were reasonably strong metal aka skid plates rather than cardboard or plastic. Waiting for a replacement HV battery due to the damage. Luckily, nothing leaked or caught fire.

 

[real mikeb_60]

Having this kind of charging widely available would be convenient, and standardizing it is a Good Thing, but in principle isn't new. Several electric bus applications of it have been done going back nearly a decade. A few that turned up in a DDG search:

Oak Ridge National Lab shuttle bus: https://www.ornl.gov/news/wireless-charging-get-bus
Link Transit Wenatchee WA: https://www.evehicletechnology.com/news ... ng-system/
Univ of Utah (2013?!): https://www.physicscentral.com/explore/ ... ic-bus.cfm
WAVE in Contra Costa Co.: https://waveipt.com/battery-electric-bu ... milestone/

 

[ExceptionsProveRules]

For this to work, EVs need to carry the extra weight of the receiving coil. If that’s not trivial, then I don’t want it lowering the driving efficiency of my car. Especially because I see no reasonable use case for wireless charging at home in my garage. I use my EVSE to charge currently (), and it’s simply not a problem to grab the cable and plug it in when I need to charge. I can’t imagine that parking the car in the position to get optimal charging efficiency is going to be any easier than plugging a cable in once or twice a week. If the charging pad has any mechanism to position the pad for the most efficient charging, then hell no. I’m not buying that kludge when a perfectly reasonable method exists. I’m willing to be convinced otherwise. But this sure seems like a solution in search of a problem.

 

[3ch0]

But why?

 

[ERIFNOMI]

For this to work, EVs need to carry the extra weight of the receiving coil. If that’s not trivial, then I don’t want it lowering the driving efficiency of my car. Especially because I see no reasonable use case for wireless charging at home in my garage. I use my EVSE to charge currently (), and it’s simply not a problem to grab the cable and plug it in when I need to charge. I can’t imagine that parking the car in the position to get optimal charging efficiency is going to be any easier than plugging a cable in once or twice a week. If the charging pad has any mechanism to position the pad for the most efficient charging, then hell no. I’m not buying that kludge when a perfectly reasonable method exists. I’m willing to be convinced otherwise. But this sure seems like a solution in search of a problem.

A few pounds of copper is fuck all compared to the literal tons of battery. It's not going to make a difference.

 

[Chuckstar]

Having this kind of charging widely available would be convenient, and standardizing it is a Good Thing, but in principle isn't new. Several electric bus applications of it have been done going back nearly a decade. A few that turned up in a DDG search:

Oak Ridge National Lab shuttle bus: https://www.ornl.gov/news/wireless-charging-get-bus
Link Transit Wenatchee WA: https://www.evehicletechnology.com/news ... ng-system/
Univ of Utah (2013?!): https://www.physicscentral.com/explore/ ... ic-bus.cfm
WAVE in Contra Costa Co.: https://waveipt.com/battery-electric-bu ... milestone/

An interesting point made about the Contra Costa buses is that they will get longer life on their batteries. They basically run the batteries between 80% and 90% of fully charged all day, and are never charging them at the highest possible power. That result is going to be unique to certain types of fleet use, though. Wider availability of charging locations could result in something similar for personal cars, where they get topped up more often, but that doesn't rely on charging pads, specifically.

 

[JKflipflop]

Can I cook a chicken on this charging pad? Maybe pop some popcorn?

No.

Actually yes. Provided one has a properly designed pan.

 

[ExceptionsProveRules]

For this to work, EVs need to carry the extra weight of the receiving coil. If that’s not trivial, then I don’t want it lowering the driving efficiency of my car. Especially because I see no reasonable use case for wireless charging at home in my garage. I use my EVSE to charge currently (), and it’s simply not a problem to grab the cable and plug it in when I need to charge. I can’t imagine that parking the car in the position to get optimal charging efficiency is going to be any easier than plugging a cable in once or twice a week. If the charging pad has any mechanism to position the pad for the most efficient charging, then hell no. I’m not buying that kludge when a perfectly reasonable method exists. I’m willing to be convinced otherwise. But this sure seems like a solution in search of a problem.

A few pounds of copper is fuck all compared to the literal tons of battery. It's not going to make a difference.

If it’s only a few pounds then I agree. Is it only a few pounds?

 

[ranthog]

Are we really put out by the simple three second task of plugging in? Is jettisoning that tedious task worth the efficiency reduction and wasted power?

How I see this being useful is not "now I don't have to plug in a cable, woohoo" but instead allowing more charging locations with less (exposed) infrastructure. Imagine a public parking lot where every spot could charge a car without having to put up charging terminals at every spot. You could have a kiosk at the end of every row or one on each floor of a multistory parking garage like you often see in paid public parking. Most of the rest of the infrastructure can run in the ground/floor. Less for people to fuck up or vandalize, less space eaten into parking spaces, and more options for charging for people who can't charge in a private garage or driveway.

Intriguing. But in this era of some regions running low on power, does it make sense to introduce infrastructure that is less efficient (and maybe more expensive) to implement over more simpler stuff that already is proven and exists. As for vandalism, that won't go away anytime soon. Troublemakers will always find a way to create trouble, unfortunately.

AFAIK... the problem isn't low power... but low peak power, where is peak demand around 4-9PM. However not every actually needs charge exactly in that time... they just need enough charge before they get back into their car. Now for DC charging... this point is moot as no one is going to accept if their DC charging solution shutoff or even reduced... but BEV owners might not mind their charging is reduce/pre-empted temporarily if the charging happens "passively" while they are at work.

I was skeptical of wireless EV charging... but people on this thread have pointed out something I hadn't considered... that you could embedded multiple wireless charging pads into the pavement for a particularly charging module. In that way, you have a much more seamless/efficient utilization of a limited number of charging stalls and less charging capacity and the added benefit not having people run around switching charging cables between vehicles in the middle of the day.

Personally, I see this a workplace option. For example imagine a company installs wireless charging pads into say 40 parking spots at its parking lot. Those 40 spots are powered by five 10KW charging. Over a work day that 8 times 5 times 10 kw = 400kWh of energy.

With the charging stalls able to send power that any charging pad... that means even if all 40 spots are use... each vehicle will get 10kw (or roughly 30-40 miles of range) per day... they will get more if not all the parking spots are occupied and/or if some of the EV need less power than their rationed allotment.

If there is a local grid/utility issue... overall draw on the power grid can be reduced... while still prioritizing people/EV who definitely need a charge (e.g. under 40% SOC) while other people (over 60%) can opt to not have their EV charged and get some type of credit/discount (in those relatively rare events).

Continuing my stream of consciousness line of thought on a tangent... in the future of V2G... you could have a combination of wired/wireless charging... where some people with home-charging could plug in their 80% SOC vehicle to let other people EV "siphon" off some of their energy... and again wireless charging pads simplify the many-to-many connections better than using only wired connections.

Even for DC fast charging it would be ideal for all the charging stations could share a pool of charging capacity (maybe in 50 kW blocks). As that way you can support a higher over all power output during busy time, as opposed to now when someone connects to a 350 kW or 150 kW charger and are not using the full capacity of the charger. Basically for a given electrical capacity you could reduce the times where all charging stations are full and reduce over head costs.

For Level 2 charging in work places having charging units where it can fairly divide up the available capacity makes a lot of sense. Especially as some workers cars will complete charging during the day, bringing up the available capacity.

 

[Wildsquirrel]

It seems like the size of the electromagnetic field that would come off one of these could be quite large. What happens to any other coil that gets within range? For example a phone with wireless charging, or if some kid is playing with a roll of wire?

 

[Chemical Tribe]

Are we really put out by the simple three second task of plugging in? Is jettisoning that tedious task worth the efficiency reduction and wasted power?

I don't think you've every had to manage a public service that involved cables. It's a fucking nightmare. Maintenance costs are through the roof. Every step you can do to eliminate contact and moving parts is almost certainly going to pay for itself pretty quickly.

It's not the 3 seconds. In one of the few studies so far of this, it was found that nearly ¼ of public EV chargers in the Bay Area didn't work when the survey was taken. That's not only a problem because it requires massive over-construction of the charging network to hit a given utility level, but you have a very real cost of people pulling up to chargers, finding they don't work, having to move their car, or then join the back of a line of people at working chargers, etc. That 3 seconds quickly becomes multiple minutes as a somewhat orderly queuing activity turns into a goat rodeo. And time isn't a particular bottleneck at gas station queues, but it at charging stations. I've witnessed Costco gas lines turn into absolute chaos when a pump went out of order after someone had waited 10 minutes to get to it and now want to effectively jump the line. Thankfully they have human attendants to sort such things out. EV charging rarely do.

But is the reason the charging cable, or

shoddy programming
using the wrong kind of hardware

Sure, cables can go bad. But funny how the EU doesn't have this issue, and from what I've learned, it's not because people fuck up charging cables. It's just that we in the US repurposed industrial electrical equipment that isn't suited to ev charging.
Now, some of the reliable charging equipment is coming to the US, and EA is already replacing charging stations with new ones that should be more reliable.

 

[mike_nz]

Can I cook a chicken on this charging pad? Maybe pop some popcorn?

No.

Actually yes. Provided one has a properly designed pan.

Actually, no. The pad has multiple safety systems integrated into it to ensure that doesn't happen.

 

[wxfreak]

If wireless charging is so efficient, why can't I wireless charge my phone in the same amount of time as plugging it in.

 

[ranthog]

Are we really put out by the simple three second task of plugging in? Is jettisoning that tedious task worth the efficiency reduction and wasted power?

I don't think you've every had to manage a public service that involved cables. It's a fucking nightmare. Maintenance costs are through the roof. Every step you can do to eliminate contact and moving parts is almost certainly going to pay for itself pretty quickly.

It's not the 3 seconds. In one of the few studies so far of this, it was found that nearly ¼ of public EV chargers in the Bay Area didn't work when the survey was taken. That's not only a problem because it requires massive over-construction of the charging network to hit a given utility level, but you have a very real cost of people pulling up to chargers, finding they don't work, having to move their car, or then join the back of a line of people at working chargers, etc. That 3 seconds quickly becomes multiple minutes as a somewhat orderly queuing activity turns into a goat rodeo. And time isn't a particular bottleneck at gas station queues, but it at charging stations. I've witnessed Costco gas lines turn into absolute chaos when a pump went out of order after someone had waited 10 minutes to get to it and now want to effectively jump the line. Thankfully they have human attendants to sort such things out. EV charging rarely do.

But is the reason the charging cable, or

shoddy programming
using the wrong kind of hardware

Sure, cables can go bad. But funny how the EU doesn't have this issue, and from what I've learned, it's not because people fuck up charging cables. It's just that we in the US repurposed industrial electrical equipment that isn't suited to ev charging.
Now, some of the reliable charging equipment is coming to the US, and EA is already replacing charging stations with new ones that should be more reliable.

My guess is that a lot of the problem stations likely are first generation stations for compliance cars in places like California. A lot of the equipment around me has been installed in the last few years and levels of failed equipment seems much lower.

So I'm guessing a large part of it is that a lot of the equipment is first generation designs which were designed for EV charging but they hadn't yet learned all the lessons yet.

 

[ranthog]

If wireless charging is so efficient, why can't I wireless charge my phone in the same amount of time as plugging it in.

Efficient does not mean fast. Speed is a different variable.

 

[Deleted member 221201]

Can I put my phone on there?

Yes, buy AppleCare

 

[YetAnotherAnonymousAppellation]

I'd like to see this extended a bit. You've got a humongous electromagnet under the car, why not allow it to attract itself to the charging plate. With a little extra metal and some alignment pins, you could get a clamping force sufficient to make it nearly impossible to move the car, giving you built-in anti-theft protection while charging.

 

[raxx7]

"Part of that is because everything that plugs into the grid needs its own isolation transformer," Gruzen continued. "We have a natural one; we have an air gap. So effectively, our two coils—the one on the ground and the one on the car—act like a transformer [and] give us the isolation naturally, and then all the rest of the electronics are pretty much the same—you're going from 240 V and 60 Hz and having to end up at whatever the car needs voltage-level in DC."

I don't see how this makes any sense. EVs, when charging on AC, would rectify and DC-DC voltage convert with solid-state components, not a transformer. What sort of isolation transformer are they referring to here?

For safety reasons electric car charging usually is done with isolated converters which will have an isolation transformer or something equivalent to break the electrical connection between the battery and the electrical grid.
The "transformer" is part of the on-board charger for AC charging or part of the EVSE for DC charging.

 

[azazel1024]

Can I cook a chicken on this charging pad? Maybe pop some popcorn?

How about fry a pacemaker, insulin pump, hearing aid, cochlear implant, or the like?

If this could fry a medical implant, it would fry every electronic device in the car, most of which are usually placed lower (and therefore closer to the charger) than practically every device you mentioned. Do you really think they haven't considered this?

Some folks don't get the inverse square law, I suppose.

After all, in a person sitting in a car that's three or so feet (at the height of the device from the plate) is getting substantially less magnetic energy than the coils that are within inches of the plate itself.

We're not talking MRI levels of magnetic energy here...

It is not the inverse square law, magnetic fields are inverse cube law. Distance has GREAT penalties with magnetic force.

 

[Wickwick]

Can I cook a chicken on this charging pad? Maybe pop some popcorn?

How about fry a pacemaker, insulin pump, hearing aid, cochlear implant, or the like?

If this could fry a medical implant, it would fry every electronic device in the car, most of which are usually placed lower (and therefore closer to the charger) than practically every device you mentioned. Do you really think they haven't considered this?

Some folks don't get the inverse square law, I suppose.

After all, in a person sitting in a car that's three or so feet (at the height of the device from the plate) is getting substantially less magnetic energy than the coils that are within inches of the plate itself.

We're not talking MRI levels of magnetic energy here...

It is not the inverse square law, magnetic fields are inverse cube law. Distance has GREAT penalties with magnetic force.

From a point source.

The magnetic field in a coil is parallel and normal to the coil (at the cross section of the coil). The coupling between coils is most certainly not well described by an inverse square or cube law.

 

[Statistical]

For this to work, EVs need to carry the extra weight of the receiving coil. If that’s not trivial, then I don’t want it lowering the driving efficiency of my car. Especially because I see no reasonable use case for wireless charging at home in my garage. I use my EVSE to charge currently (), and it’s simply not a problem to grab the cable and plug it in when I need to charge. I can’t imagine that parking the car in the position to get optimal charging efficiency is going to be any easier than plugging a cable in once or twice a week. If the charging pad has any mechanism to position the pad for the most efficient charging, then hell no. I’m not buying that kludge when a perfectly reasonable method exists. I’m willing to be convinced otherwise. But this sure seems like a solution in search of a problem.

A few pounds of copper is fuck all compared to the literal tons of battery. It's not going to make a difference.

Also weight doesn't really impact efficiency that much. I wish this myth would die. Most of the energy consumption in the lifecycle of the vehicle is overcoming drag so the drag of the vehicle matters much more. Yes a heavier vehicle requires more energy to accelerate but that is already a small fraction of total energy but then most of that is recovered when you slow back down via regenerative braking.

 

[Wickwick]

For this to work, EVs need to carry the extra weight of the receiving coil. If that’s not trivial, then I don’t want it lowering the driving efficiency of my car. Especially because I see no reasonable use case for wireless charging at home in my garage. I use my EVSE to charge currently (), and it’s simply not a problem to grab the cable and plug it in when I need to charge. I can’t imagine that parking the car in the position to get optimal charging efficiency is going to be any easier than plugging a cable in once or twice a week. If the charging pad has any mechanism to position the pad for the most efficient charging, then hell no. I’m not buying that kludge when a perfectly reasonable method exists. I’m willing to be convinced otherwise. But this sure seems like a solution in search of a problem.

A few pounds of copper is fuck all compared to the literal tons of battery. It's not going to make a difference.

Also weight doesn't really impact efficiency that much. I wish this myth would die. Most of the energy consumption in the lifecycle of the vehicle is overcoming drag so the drag of the vehicle matters much more. Yes a heavier vehicle requires more energy to accelerate but that is already a small fraction of total energy but then most of that is recovered when you slow back down via regenerative braking.

Also, even the mass impact is as a ratio of the overall mass. A few kg difference in a tonne isn't going to have a measurable impact on efficiency during acceleration or even rolling resistance.

 

[Spiders from Mars]

This is why military and aerospace electrical systems prefer 400hz AC where possible, the high switching frequency enables smaller, lighter, more efficient transformers and motors.

Sort of (a tiny bit) like how hydraulic systems in modern aerospace applications use very high hydraulic pressures, like 5000 psi, to permit smaller lighter tubing and actuators. Previously 3000 psi, then 4000 psi, was the standard.
In the future all-electric aircraft systems will be the standard, but we're not quite there yet.

 

[ERIFNOMI]

For this to work, EVs need to carry the extra weight of the receiving coil. If that’s not trivial, then I don’t want it lowering the driving efficiency of my car. Especially because I see no reasonable use case for wireless charging at home in my garage. I use my EVSE to charge currently (), and it’s simply not a problem to grab the cable and plug it in when I need to charge. I can’t imagine that parking the car in the position to get optimal charging efficiency is going to be any easier than plugging a cable in once or twice a week. If the charging pad has any mechanism to position the pad for the most efficient charging, then hell no. I’m not buying that kludge when a perfectly reasonable method exists. I’m willing to be convinced otherwise. But this sure seems like a solution in search of a problem.

A few pounds of copper is fuck all compared to the literal tons of battery. It's not going to make a difference.

Also weight doesn't really impact efficiency that much. I wish this myth would die. Most of the energy consumption in the lifecycle of the vehicle is overcoming drag so the drag of the vehicle matters much more. Yes a heavier vehicle requires more energy to accelerate but that is already a small fraction of total energy but then most of that is recovered when you slow back down via regenerative braking.

Yeah, regen definitely takes care of a lot of weight. Overcoming aero is the main concern, which of course increases with speed.

 

[android_alpaca]

For this to work, EVs need to carry the extra weight of the receiving coil. If that’s not trivial, then I don’t want it lowering the driving efficiency of my car. Especially because I see no reasonable use case for wireless charging at home in my garage. I use my EVSE to charge currently (), and it’s simply not a problem to grab the cable and plug it in when I need to charge. I can’t imagine that parking the car in the position to get optimal charging efficiency is going to be any easier than plugging a cable in once or twice a week. If the charging pad has any mechanism to position the pad for the most efficient charging, then hell no. I’m not buying that kludge when a perfectly reasonable method exists. I’m willing to be convinced otherwise. But this sure seems like a solution in search of a problem.

A few pounds of copper is fuck all compared to the literal tons of battery. It's not going to make a difference.

Also weight doesn't really impact efficiency that much. I wish this myth would die. Most of the energy consumption in the lifecycle of the vehicle is overcoming drag so the drag of the vehicle matters much more. Yes a heavier vehicle requires more energy to accelerate but that is already a small fraction of total energy but then most of that is recovered when you slow back down via regenerative braking.

I think reduced efficiency from increased weight is a death by a thousand cuts via feature creep/bloat. Imagine a system/module team thinking "oh a few kg doesn't matter" in isolation... but over a dozen system/modules it would add up - so someone needs to look at feature vs weight holistically and make a decision if it is needed for this particular model vehicle as a standard feature.

I found this study that suggested trimming 240 kg would lead to a 10% increase in efficiency. So again it's the age-old practice of balancing the "cost" of a feature vs how likely the feature will actually be used.

 

[majortom1981@aol.com]

This is a good idea. Thieves have started to take charging cables off of charging spots.

 

[ferdnyc]

What happens to stuff (stuff being anything from a persons limb, to animals, etc) that are between the two coils? Does anyone have reading material on how the two coils transfer this energy?

See Eric Giler's original TED talk on WiTricity: https://youtu.be/y1GqNN2Xe7g

He walks between the sending pad and the phone that's being powered off it, and at least doesn't immediately keel over. Though, he's rarely heard from anymore, so make of that what you will. (Kidding, they claim it's perfectly safe.)

 

[Xzyl]

Besides being able to serve those in apartment's or with only street parking (or those stuck with both) I could see a potential industrial. The inroad use case examples got me thinking; what if it were used in a warehouse to keep electric forklifts charged?

 

[ERIFNOMI]

Besides being able to serve those in apartment's or with only street parking (or those stuck with both) I could see a potential industrial. The inroad use case examples got me thinking; what if it were used in a warehouse to keep electric forklifts charged?

I believe someone already has wireless charging in the material handling world. There are also automated, contact charging methods. Something standardized would be nice, but then you can't lock people into your trucks.

 

[Boskone]

Can I cook a chicken on this charging pad? Maybe pop some popcorn?

No.

I know the original post was made in jest, but I’m going to ask a question out of ignorance. What is the technical difference between wireless charging and an induction cooktop?

Not a lot of difference. The induction cooktop causes eddy currents induced in the base of your cooking pot which heats the metal very quickly. There will be safeguards in place on the car chargers to prevent heating, ie you can't stick a saucepan on it and expect it to heat up (or melt!?)

Nuts. So much for my charging pad/outdoor kitchen idea.

 

[Matthew J.]

If they made one that could serve something between 10kW and 20kW and for less than $1000, I might get one for my driveway...

 

[m0nckywrench]

Why bother saving electricity if you're going to piss it away on a ginormous transformer using thirty kilos of copper?

As BEVs are adopted by the majority who at most pretend to care about the environment (techie and general public overlap is modest on a good day or we'd be living in a much different world...) convenience will be a major priority.

Electricity is only money and users with big toy money can afford to "fuel" their choices. Their purchases are why we have BEVs so be happy. Selling to the higher end always makes sense because poor people buy used vehicles they really want instead of econoboxes they don't.

 

[m0nckywrench]

Besides being able to serve those in apartment's or with only street parking (or those stuck with both) I could see a potential industrial. The inroad use case examples got me thinking; what if it were used in a warehouse to keep electric forklifts charged?

That's major money towards an already solved warehouse problem of plugging in forklifts at end of shift at their designated parking spot. You can easily relocate a forklift charger (with the forklift as they're heavy) to run off any power "drop" or wall cord you desire. Adding a heavy wireless charger whose housing must either be armored (if mobile) and have shallow approach angles (see indoor forklift wheels and chassis heights for why) or expensively built-in if fixed is questionable when Bubba charges his steed properly most of the time so he doesn't have to get chewed out and/or use a manual pallet jack.

 

[ERIFNOMI]

Besides being able to serve those in apartment's or with only street parking (or those stuck with both) I could see a potential industrial. The inroad use case examples got me thinking; what if it were used in a warehouse to keep electric forklifts charged?

That's major money towards an already solved warehouse problem of plugging in forklifts at end of shift at their designated parking spot. You can easily relocate a forklift charger (with the forklift as they're heavy) to run off any power "drop" or wall cord you desire. Adding a heavy wireless charger whose housing must either be armored (if mobile) and have shallow approach angles (see indoor forklift wheels and chassis heights for why) or expensively built-in if fixed is questionable when Bubba charges his steed properly most of the time so he doesn't have to get chewed out and/or use a manual pallet jack.

Probably no point for a cheap forklift that's already going to be operated by someone who can plug it in when they're done. But for autonomous forklifts, it would make a lot more sense. They can go sit in a staging area during any downtime and keep topped up as much as possible. There the added cost of wireless charging isn't going to be as big of a deal and probably pays for itself by not having to pay someone to babysit the batteries all day.

 

[Richard Gadsden]

Some use cases:

Apartment parking lots/garages. These tend to be really tightly packed, so there isn't room to put in wired stalls, but wireless charging would make a lot of sense. Lots of people living in an apartment can't charge at home, but wireless charging in the apartment lot would solve that.

Hotel parking - Level 2 is generally enough (cars necessarily spend a long time in parking lots at hotels, so there's no need for faster charging). They could put in a Level 2 wired charger, but not having a thing that an idiot/drunk driver can collide with is going to be very tempting.

Parking garages in cities (not parking lots, but proper garages that are under cover so don't have to concern themselves with snow) - even if you only get a few hours while you're at work, that's still a few hours.

Taxi ranks - Being able to trickle in a bit of charge between customers is something I suspect most taxi drivers will appreciate.

Pricing is going to be interesting, becuase the amount of money charged for an hour or two at 11kW is low enough that transaction fees will be a big chunk of costs, and they won't want to pay a credit card processing fee for each individual transaction.

I suspect that a lot of upper-tier hotels will throw in a free charge with the room rate, or will do so for people with a high enough status in their loyalty scheme (like they do with WiFi). Cheaper hotels will definitely want to charge for usage.

Apartments might just add a sum onto your monthly condo fees (service charge in Britain) for access to the charging system, rather than metering the actual electricity used. Sure, some people will do more miles than others, but apartment residents with really high milages are going to be rare enough and apartment blocks big enough that it's unlikely to be worth the hassle of metering. People without an EV will just not have access to the charging system and not pay the fee. On the other hand, they can aggregate up the usage over a month and bill you, so it might be a small enough hassle that that would be preferred.

Parking garages are going to have to operate on a per-kWh basis, because some people will be just topping up and others will be coming in with almost no charge, and they will have to deal with adverse selection (people only wanting a bit of power will go to places that charge by the kWh, people wanting a lot will prefer a flat fee).

Taxi ranks will probably issue a card to a cab company and send them an aggregated bill once a month or so, rather than trying to do each individual charge as a separate transaction

 

[Chuckstar]

Some use cases:

Apartment parking lots/garages. These tend to be really tightly packed, so there isn't room to put in wired stalls, but wireless charging would make a lot of sense. Lots of people living in an apartment can't charge at home, but wireless charging in the apartment lot would solve that.

Hotel parking - Level 2 is generally enough (cars necessarily spend a long time in parking lots at hotels, so there's no need for faster charging). They could put in a Level 2 wired charger, but not having a thing that an idiot/drunk driver can collide with is going to be very tempting.

Parking garages in cities (not parking lots, but proper garages that are under cover so don't have to concern themselves with snow) - even if you only get a few hours while you're at work, that's still a few hours.

Taxi ranks - Being able to trickle in a bit of charge between customers is something I suspect most taxi drivers will appreciate.

Pricing is going to be interesting, becuase the amount of money charged for an hour or two at 11kW is low enough that transaction fees will be a big chunk of costs, and they won't want to pay a credit card processing fee for each individual transaction.

I suspect that a lot of upper-tier hotels will throw in a free charge with the room rate, or will do so for people with a high enough status in their loyalty scheme (like they do with WiFi). Cheaper hotels will definitely want to charge for usage.

Apartments might just add a sum onto your monthly condo fees (service charge in Britain) for access to the charging system, rather than metering the actual electricity used. Sure, some people will do more miles than others, but apartment residents with really high milages are going to be rare enough and apartment blocks big enough that it's unlikely to be worth the hassle of metering. People without an EV will just not have access to the charging system and not pay the fee. On the other hand, they can aggregate up the usage over a month and bill you, so it might be a small enough hassle that that would be preferred.

Parking garages are going to have to operate on a per-kWh basis, because some people will be just topping up and others will be coming in with almost no charge, and they will have to deal with adverse selection (people only wanting a bit of power will go to places that charge by the kWh, people wanting a lot will prefer a flat fee).

Taxi ranks will probably issue a card to a cab company and send them an aggregated bill once a month or so, rather than trying to do each individual charge as a separate transaction

It’s not clear why any of those use-cases require wireless charging. High density parking? A long wire works great for that. Can even have the wire on a reel. That’s how they do it in the high-density parking garage near me. Way more efficient than having to move cars onto a limited number of pads. Or just have a wire at each stall in an apartment complex. Not clear why apartment parking is somehow bad for that setup.

 

[Amateur Nerd]

Interesting video about this from Undecided

 

[ScifiGeek]

Also weight doesn't really impact efficiency that much. I wish this myth would die. Most of the energy consumption in the lifecycle of the vehicle is overcoming drag so the drag of the vehicle matters much more. Yes a heavier vehicle requires more energy to accelerate but that is already a small fraction of total energy but then most of that is recovered when you slow back down via regenerative braking.

It's not a myth. Lighter EVs are more efficient in the city. You can see it practically every EV with different battery sizes. The ones with smaller batteries are more efficient.