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GM Partners With Boston Startup WiTricity To Develop Wireless Charging Technology (electrek.co) 61

Earlier this week, General Motors announced a partnership with Boston-area startup WiTricity to develop wireless charging pads for electric vehicles. Their goal is to develop a wireless "charging pad" that can be installed beneath a layer of concrete or other garage flooring material so that cars would simply need to be parked over the pad to automatically start charging. Electrek reports: "The electric vehicle has been recognized as central to the future of mobility, and GM has been a leader, making EVs accessible to the broader market. The convenience of wireless charging will help accelerate adoption even further," said Alex Gruzen, CEO of WiTricity, about the alliance. "Wireless charging for EVs, based on industry standards, is inevitable as we move toward a future of self-driving and autonomous vehicles, and this project brings us one step closer to realizing our vision of a world powered wirelessly." GM agreed to allow WiTricity to conduct tests on a Chevrolet Volt hybrid vehicle, "to show how well it would work integrated into a real car," according to Gruzen. Witricity claims that their system can achieve over 90% efficiency, which would make it at least as efficient as a plug-in charger. "Wireless charging is a technology that our customers have told us they are interested in," GM's executive chief engineer of electrified vehicles, Pamela Fletcher, said. "By testing the WiTricity prototype system, we can ensure that wireless charging systems will comply with proposed industry standards, which benefits the entire industry and consumers." The company has high hopes for their product. Gruzen envisions a future in which EV owners can send autonomous cars to charging stations remotely, a future that would only be possible with wireless charging stations.
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GM Partners With Boston Startup WiTricity To Develop Wireless Charging Technology

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  • wireless charging is a waste ofenergy
    how long does it take to plug something in

    And wasting energy is particularly bad when we have climate deniers in charge of the govt

    • Re:What a waste (Score:5, Insightful)

      by donaldm ( 919619 ) on Saturday December 24, 2016 @05:59AM (#53547479)

      wireless charging is a waste ofenergy how long does it take to plug something in

      And wasting energy is particularly bad when we have climate deniers in charge of the govt

      Wireless or inductive [wikipedia.org] charging can be as efficient as charging via cable but there are also allot of gotchas as well. One of those gotchas is a fundament law of physics which simply states that if you want efficiency you must couple the magnet field of the charging coil with the receiving coil and the greater the air gap the less efficient the charging will be. Anyone who has done transformer design should know that.

      Charging mats for your mobile are not that efficient but they are convenient and the loss in monetary terms is small so most people won't care, but if you upscale inductive charging to a car the losses are going to be much more evident and this translates to extra costs for the consumer which will far outweigh the convenience.

      • by Anonymous Coward

        If you park above a charging plate, why wouldn't it simply connect directly, like a tram connects to the line above using a pantograph.

      • Re:What a waste (Score:5, Interesting)

        by burtosis ( 1124179 ) on Saturday December 24, 2016 @07:13AM (#53547609)
        It's not exactly just the gap that creates inefficient coupling but the ratio of the area of the field to the gap. Therefore on a car where the field is coupled across nearly the whole width the gap can be somewhat large compared to a phone and still not be too bad.

        There are other gotchas though such as what if stray pieces of conductive material get in the way? If the vehicle is going to actually charge at a reasonable rate then some stray piece of metal can be a real problem in terms of picking up energy and heating. You could carefully monitor the power on both sides but it's hard to say if the difference is going to heat something. Another is broadcasting all kinds of errant emissions. When you broadcast that much power even little screwups like not parking in the exact right spot or minor damage to the bottom of the car could create tons of unwanted noise at all kinds of frequencies.

        While it sounds cool to wirelessly charge, in reality it's likely to be far more practical and inexpensive to just use a plug.
        • While it sounds cool to wirelessly charge, in reality it's likely to be far more practical and inexpensive to just use a plug.

          Unless it is a ubiquitous standard charger, I doubt many would invest in having it embedded in a concrete floor. It sees a mat that sits on the floor would be more desirable.

          Of course, a huge number of people don't have garages or can't get all their cars into their garages, so plugs will still be the default. This embedded charger would be more of a nice accessory.

        • "Wireless charging is a technology that our customers have told us they are interested in," GM's executive chief engineer of electrified vehicles, Pamela Fletcher, said.

          Just how many customers does GM have and what was the vote count? Simple majority or landslide?

        • by eth1 ( 94901 )

          This is exactly what I was thinking. The EM noise from transferring that much power like that seems like it would be insane. Don't go near it with any electronics?

          I would think a simple system where you essentially have an upside down pantograph on the bottom of the car would be the most straightforward way of doing it, as well as having the potential to power the car in motion as well. There could be some safety issues with exposed contacts on the floor, but requiring the pantograph to exert several hundre

        • There are other gotchas though such as what if stray pieces of conductive material get in the way? If the vehicle is going to actually charge at a reasonable rate then some stray piece of metal can be a real problem in terms of picking up energy and heating. You could carefully monitor the power on both sides but it's hard to say if the difference is going to heat something. Another is broadcasting all kinds of errant emissions. When you broadcast that much power even little screwups like not parking in the exact right spot or minor damage to the bottom of the car could create tons of unwanted noise at all kinds of frequencies.

          You included the key word in your own text. Broadcasting is specifically what they are not doing. Everybody agrees that a purely radiant broadcast is a terrible way to move power wirelessly. That's why WiTricity intends to use resonant antennas [wikipedia.org], as described here [witricity.com]. That prevents both heating of stray objects, because essentially no stray metal objects will be the right size to resonate, and prevents broadcast noise, because very nearly all the power is confined to the near field.

      • by AaronW ( 33736 )

        That's my feeling as well. They claim up to 90% efficiency if you park just right, but a cable is a lot more efficient. When I'm charging at 20KW (as I can do in my garage), I don't need a 2KW heater as well. Normally I charge at 10KW since there's a lot less line loss. I see an 8v drop between my meter and my charger when charging at 20KW. Though the cable gets warm I don't see any significant drop between the charger and my car. Just charging at 80A means I'm wasting 640 watts as heat in the 100 foot run

    • a wireless power supply sweet i need 1 for each room in my house & 1 for the office no more cords laying around to trip on.
    • wireless charging is a waste of energy

      There is no question that this will work. The question is, how efficiently, in comparison to a plug-in connection? Currently, the big disadvantage of electric cars is no longer range, but charging time. If we can 'gas up' as we are parked at a diner at 90% efficiency, that could be a tipping point for the technology.

  • by Mal-2 ( 675116 ) on Saturday December 24, 2016 @05:21AM (#53547443) Homepage Journal

    If we as a civilization have figured out how to dock spacecraft, and refuel planes in flight, surely we can figure out how to connect an autonomous car to a contact charger. It could be a port at bumper height and the car drives very slowly into it. It could be simple robots at the station itself. I'm not saying wireless charging doesn't have its place, but it is not a requirement for an autonomous vehicle infrastructure.

    • If we as a civilization have figured out how to dock spacecraft, and refuel planes in flight, surely we can figure out how to connect an autonomous car to a contact charger. It could be a port at bumper height and the car drives very slowly into it. It could be simple robots at the station itself. I'm not saying wireless charging doesn't have its place, but it is not a requirement for an autonomous vehicle infrastructure.

      ^^This, exactly! With the sophistication level of the robotics we already have in daily use, having cars either plug in or be plugged in would be a relatively trivial task. Granted, things like snow, ice, and dirt buildup, (among others), would cause problems - but they will also cause problems with wireless charging schemes. Not to mention the cost of repair. What's going to be more expensive - hiring a guy to fix or replace an above-ground piece of automation, or hiring a construction crew to dig up the a

    • We could have automated gasoline refueling already if we really wanted and needed to. But we didn't really want or need to. We don't need to do it for EVs, but we may want to. Its simply not that big of a deal to plug a car in.
    • Someone else posted this automatic charger:
      http://www.theverge.com/2016/6... [theverge.com]

      The electronic guidance needn't be any more complex than the Lego Mindstorms line/ligght following robot, recommended for kids 10 years old and up.

      This kit does essentially the same thing and costs £16.50.

      https://www.kitronik.co.uk/219... [kitronik.co.uk]

    • I'm pretty sure neither of the things you mention are autonomous. We haven't figured it out which is kind of the point.

    • MagPlug!
  • by packrat0x ( 798359 ) on Saturday December 24, 2016 @05:44AM (#53547457)

    "Wireless charging is a technology that our customers have told us they are interested in",
    our customers also want flying cars.

  • by Anonymous Coward

    need some proof. It'll take some work to convince me that 90% is even near of theoretical possibilities, let alone practical realities.

    I'd say: startup snake oil.

  • Gruzen envisions a future in which EV owners can send autonomous cars to charging stations remotely, a future that would only be possible with wireless charging stations.

    This dude and his garage begs to differ http://www.theverge.com/2016/6... [theverge.com].

    GM if anyone would have the engineering resources to put together a reliable and automatic physical charging connection.

    /greger

  • by hackertourist ( 2202674 ) <.ln.tensmx. .ta. .tsiruotrekcah.> on Saturday December 24, 2016 @07:53AM (#53547655)

    They claim a few meters of cable and a plug are only 90% efficient. ("which would make it at least as efficient as a plug-in charger")
    If that were true, charging at 20 kW would result in red-hot cables. So this claim is bullshit.

    • by short ( 66530 )

      The supercharger cables get warm but they charge at 150 kW. Tesla has been experimenting with some supercharger liquid cooling according to googling. But 90% is not just about the cable, probably most of those 10% is lost during the chemical charging of the battery itself. And Tesla battery HVAC runs on full power when the car is being supercharged.

      I do not advocate the wireless charging itself, that is a non-sense IMO.

      • Chemical losses also occur during wireless charging. When comparing wireless and wired charging, the only metric that counts is the transmission losses. If they're including other losses without specifying them, their numbers are meaningless.

    • by Ozoner ( 1406169 )

      Came here to say this. The inefficiency is an ADDITIONAL inefficiency to that lost in the charger.

  • by wbr1 ( 2538558 ) on Saturday December 24, 2016 @09:47AM (#53547877)

    Gruzen envisions a future in which EV owners can send autonomous cars to charging stations remotely, a future that would only be possible with wireless charging stations.

    Uhhhh... no. With the state of computer vision (used by autonomous cars of all things), you can easily program a device to automatically align and plug in a cable. Wireless is just a drop in efficiency. Right now, with the state of battery storage and the goal of ostensibly reducing emissions, you would think efficiency would be engineering goal #1.

    • by JBMcB ( 73720 )

      How about combining the two technologies so you don't have to worry about the socket getting dirty, or the plug wearing out, or having different standards of plugs? If the charging inductor is on the end of a robotic arm, it can get it right next to the inductor on the car, and your inductive loss goes down to nearly zero.

  • by mykepredko ( 40154 ) on Saturday December 24, 2016 @12:30PM (#53548445) Homepage

    The biggest concern about EVs is the limited range and the need to constantly charge them.

    Having cheap, wireless chargers that can be embedded into concrete means that drivers can constantly keep their vehicles charged - whether it's in the city in parking spots, at home or on trips where they should be getting out and walking around every 1.5 to 3 hours (100 to 200 miles) for their health. Every time they stop, their cars are being charged/topped up so they never have to worry about running out of charge.

    If cities put in wireless chargers in street parking spots, they can provide a service that EV owners would be willing to pay for (and I imagine that the link/payment would be automatic and keyed to the car's license so it's convenient for the owners).

    If businesses put in wireless chargers into their parking lots, then they have an additional source of revenue as well as a reason for EV owners to come directly to them.

    As many people have noted, wireless charging isn't as efficient as a direct connection and there will be huge infrastructure costs to install the chargers, power to them and network connections as well as add them to existing EVs as well as design them into future vehicles, but there seems to be a pretty strong business case that will make this type of technology very desirable in the near future.

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