Highway Charging While Driving

[carpedatum]

Interesting. Qualcomm worked on a stationary version of wireless car charging a while back. They eventually sold "Halo" to a startup (WiTricity). They solved a lot of fundamental problems (e.g. making it safe, because the crispy critter problem is real). The one I never heard an answer for was a really big question, and the reason, I think, why Qualcomm gave up.

If you can get significantly better power transfer efficiency by plugging the car in, when will it get interesting to spend more for wireless? It would somehow not have to matter that we add weight to the vehicle, and lose more energy transferring the juice. Given the volume of energy that has to be moved to support an EV, even a 10% loss seems sad.

It already doesn't matter with phones because the math works better for small devices. Hard to see how we get there for EVs, even if it could be made practical.

Looks like the company behind this charging-at-speed story has a handful of projects in flight, but none operational yet. All of those other projects are for large, heavy things (busses and trucks). This seems really aspirational! I'm surprised Ford wants to get into this, at this stage.

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[Zapharus]

Does is just sound sexier to do this on roads? It seems like a way better use case would be to try this in stationary parking spaces (parking lots). I would love to have wireless charging in a garage some day. Roads are also extremely difficult to maintain and any work on the "charger" interrupts traffic. Not to mention all the other challenges purely around charge rate and the amount of surface you would need to cover to do any practical amount of charging.

Exactly! BMW has been working on such a tech. I hope Tesla eventually does something like that for home charging too.

 

[Zapharus]

My phone does charge through the air as does my toothbrush and as do a couple of cars and trucks. Charging inductively at L2 rates with 90% efficiency has been demonstrated in both commercial and private vehicles and several manufacturers claim to be a year or so away from offering systems. There is no question as to the technical feasibility. The real question is as to whether the additional technical complexity (costs) are justified by the advantages.

“Through the air…” phones have to rest on the charging pad to work. In the case of the toothbrush, if you’re referring to the Philips Sonicare (one of which I own), then that fits this “through the air” narrative because there’s a thick glass between the charger and the toothbrush. But a true through-the-air mass-market device does not exist yet.

 

[ajdelange]

But a true through-the-air mass-market device does not exist yet.

Suppose it depends on how you describe “mass” but BMW is making this available to its customers. Try to understand how it works and perhaps you will stop making such foolish statements.

 

[Zapharus]

Suppose it depends on how you describe “mass” but BMW is making this available to its customers. Try to understand how it works and perhaps you will stop making such foolish statements.

How is it a foolish statement? I’m aware of the BMW device, I’ve even linked a video from BMW in my reply to other comments. And in the portion of my comment that you quoted I clearly stated “yet,” meaning that it’s not currently on the market in mass quantities but it doesn’t mean it’s not coming. But by all means, feel free to continue getting triggered. Lol

Just in case you’re curious, this is the video I shared with others prior to even coming across your comment:

 

[RandyS]

I'm okay with plugging in my own car in the garage and probably wouldn't use wireless charging due to losses, cost of equipment, and precise positioning requirements. For fleet use, though, I can see some benefits for wireless charging. People that don't drive one of the fleet EVs very often would forget to plug in pretty frequently after their drive where I work. The next day the car would not necessarily be ready to drive, so I can understand wireless charging for fleets or even autonomous vehicles.

But this whole idea of putting charging in a lane of a road or highway doesn't grab me at all. It would cost a ton to build, cars would have to have the "receiver" installed underneath, and drive in that lane for many many miles to get any sort of decent charge. I just don't see the cost/benefit for such a project vs. just installing some charging stations. I don't want to take a 1,000 mile road trip without stopping anyways for food or restrooms, so it's not really an attraction for me to drive all day and night without stopping.

And what happens when there are 20 or 50 or 100 cars all trying to charge in that lane? The power requirements just aren't practical for that...Since funding for EV/charging projects is usually limited, I'd just rather seeing more charging stations put in instead of investing the $$$$$ that it would take to prototype on-road charging...

 

[Cyberman]

Extremely wasteful. Induction charging sees efficiency losses in the 30% range when the coils are mm apart. Now they are talking about coils that are 10+ cm apart. If the energy is produced by mostly renewable energy then I guess its not an issue, but still wasteful. If that electricity is produced by fossil fuels which it very likely is and you are losing 30% to 50% in efficiency loss (probably more), Then we are getting into the efficiency range of ICE engines and still producing a similar amount of greenhouse gases.

Its all a discussion of where the energy comes from and could it be used for better purposes. Also, you will probably see warning signs on the road about driving on them with sensitive medical equipment, pacemakers etc., as magnetic frequency induction type charging can mess with such devices.

Boom. There you have it. Just like that, in less than three days, an intelligent observer makes enough of a case to show how implausible this system is.

I can maybe see it being useful for the emergency shoulder lane in areas where the next charging station is quite far and one is getting pretty low on battery, so one would pull over on the side of the road to charge a bit for an hour to get enough charge to get to the next wired charger. This of course would only be used in emergency situations which is why it would take an hour to get just 40-ish miles worth of charge from such a system because I highly doubt it has efficient charging speed. All of this is of course a very ideal situation and only used for emergencies which is the only time someone would be desperate enough to even want to park for an hour for a measly 40-ish range top off.

Park for an hour...in Detroit?!?!?!

 

[CyberGus]

Stationary wireless charging is a good place to start. It would eliminate many of the challenges of public charging: vandalism, broken/incompatible plugs, use of space, etc.

Wired charging isn't lossless. Charge cables turn into heater wire at high amperages, and gets worse with length and thinness.

 

[Zapharus]

Boom. There you have it. Just like that, in less than three days, an intelligent observer makes enough of a case to show how implausible this system is.

Park for an hour...in Detroit?!?!?!

Hence why I stated “in a very ideal situation.” But if someone runs out of battery they really won’t have a choice either way. lol

 

[ajdelange]

Extremely wasteful. Induction charging sees efficiency losses in the 30% range when the coils are mm apart. Now they are talking about coils that are 10+ cm apart.

Boom. There you have it. Just like that, in less than three days, an intelligent observer makes enough of a case to show how implausible this system is.

As the first quote is dead wrong I wouldn't say the obseration was particularly intelligent.

 

[CyberGus]

The BMW 530e Hybrid has a 9kWh battery.

 

[Crissa]

A charged plate has an electrical field, for it to make a magnetic field you would need to be flowing electrons.

While that's true, that doesn't mean there's no magnetic field. It means it's very small.

And you can't pass that current from something charged to something missing electrons without creating a magnetic field. Without a loop, it'll be unaligned and small, but it will exist.

Electrical power doesn't just move from electron transfer, but from the fields they perturb as they move around. Magnetic fields and radio waves are just the effects we can sense at a distance... but sometimes not very far at all.

-Crissa

 

[Crissa]

And what happens when there are 20 or 50 or 100 cars all trying to charge in that lane? The power requirements just aren't practical for that...Since funding for EV/charging projects is usually limited, I'd just rather seeing more charging stations put in instead of investing the $$$$$ that it would take to prototype on-road charging...

Well, every car will be over a different induction loop.

You just argued that we can't charge 20 or fifty cars in a parking lot. Or used multiple electric tools in a town.

While this means that rush hour would become prime-time for power consumption.

But... we're throwing around efficiencies without knowing what they'll be. And we can't know if they don't build tests like this one.

We lose energy carrying around battery packs. We lose energy charging those packs. We use rarer and less safe metals to pack so much energy into cars when we could use less rare and more stable metals for stationary batteries.

We just don't know without trying.

-Crissa

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