8 ms·

The limit is the battery chemistry or the chemistry related internal resistance of the battery, not the cable. Lowering the resistance of the cable helps keep t

• ypcx 5y ago
  Forget all that. If we tried to swich half the cars to electric overnight, the power grid would collapse into a permanent blackout. Has anyone estimated the cost and time of upgrading the power grid for electric cars? Is hydrogen delivery from power plants to electric charging stations a viable option to bridge the gap until the grid is upgraded?
  • tonyedgecombe 5y ago
    >If we tried to swich half the cars to electric overnight It's a good job nobody is suggesting that then. >Has anyone estimated the cost and time of upgrading the power grid for electric cars? I don't know about the US but in the UK we just need to take generation back to 2002 levels to cover the whole fleet moving to electric.
    • Balero 5y ago
      I think the biggest issue in the UK is how to get cars parked on street to be charged overnight. In towns and cities (and elsewhere too) it is very common to park your car on the street, potentially a good distance away from your home. Where exactly to build the charging infrastructure for people parking like this. I guess if you only need to charge at the same frequency as you would refuel you could have chargers in super market parking lots. Cars charge whilst you do your weekly shop. Or at work, if they have space. I also heard about one idea to have chargers at every street light, as they already have an input from the grid in them. Hopefully this is an issue that can be solved without having to re-wire huge portions of the urban areas.
      • clouddrover 5y ago
        > I think the biggest issue in the UK is how to get cars parked on street to be charged overnight. Do it with wireless charging: https://www.youtube.com/watch?v=aq7SP18sPKw https://www.youtube.com/watch?v=aq7SP18sPKw https://www.youtube.com/watch?v=9IoPA0rq0yw https://www.youtube.com/watch?v=9IoPA0rq0yw
      • rbanffy 5y ago
        > Where exactly to build the charging infrastructure for people parking like this. On the sidewalks. There are a number of chargers like that in the city I live that are more or less subscription based. > Cars charge whilst you do your weekly shop. Or at work, if they have space. That's one excellent solution. You can take the money that won't be spent with healthcare (because air pollution) and channel it as incentives to build out that infrastructure. > I also heard about one idea to have chargers at every street light, as they already have an input from the grid in them. That's another interesting idea, if the power is available. With the move to efficient lighting, the need for power has been reduced and I assume the cable gauges have reflected that. > Hopefully this is an issue that can be solved without having to re-wire huge portions of the urban areas. If the cars can recharge for hours, the need to rewire for higher currents is smaller.
        • lttlrck 5y ago
          I guess street chargers work great if you park on the street and can leave your EV in the same spot even after it is charged, like a regular parking spot. Otherwise it's just a chore to charge and move your EV to a non-charging spot when it's finished (of which there would be fewer)?
        • greedo 5y ago
          Are there any safety/vandalism concerns with leaving a car charging unattended?
          • rbanffy 5y ago
            It's not more or less susceptible than a parked car.
  • wil421 5y ago
    No they wouldn’t. Steam turbines can take days to ramp up and connect to the grid. Several dams in my state barely reach full capacity and are not running 24/7. The co-op that supplies my power offers a flex plan that gives you free power from 11pm-6am. You’re supposed to schedule your car to charge during that time. If half the cars in my county did this nightly it would be easier to predict the nightly loads.
    • RcouF1uZ4gsC 5y ago
      > The co-op that supplies my power offers a flex plan that gives you free power from 11pm-6am. Can you sign up for that plan and just mine Bitcoin during that time?
      • loonster 5y ago
        Just call it an electric heater.
      • obiwan14 5y ago
        I get free eletricity from 8pm - 5am. And yes, I did mining for while during that time frame when it was still possible to mine with one GPU.
    • jacquesm 5y ago
      But then it almost certainly wouldn't be free anymore.
      • deleted 5y ago
        [deleted]
      • ZeroGravitas 5y ago
        It probably will still provide some "payment" back, as long as some control is allowed for the grid operator. At the moment they're happy with "charge any time between these hours", once everyone starts doing it it'll probably be "free if you leave your car plugged in and let us decide when and how much to charge". Shifting demand has a price and they'll pay that to the users that help them achieve it in some form or other. After all, if you don't charge it then, they'll need to provide the power later when it could cost them many multiples, it's just good business sense.
  • ben_w 5y ago
    If we were to try to switch all vehicles to EV “overnight”, we’d almost certainly also mandate PV on all car rooftops. I have observed that discussion of this solution normally divides into these two groups: (1) “That’s ridiculous, a car covered in with PV will only make enough electricity to go 10-30 miles per day!” (2) “That’s a great idea, a car covered with PV will make enough electricity to go 10-30 miles power day, and most people only go 12-35 miles per day!” When there is serious concern if the grid can cope, we should take all the mitigations we can get. Reducing aggregate charging demand by 90% is good even when every single driver still needs to use an external charger.
    • jimrandomh 5y ago
      Car rooftops are a bad place for PV cells because in hotter climates, people park in the shade to avoid overheating their car's interior.
      • ben_w 5y ago
        Suboptimal, but this was a hypothetical about “overnight”.
  • natch 5y ago
    Just because you can't think of a solution does not mean others have not already thought of solutions. Rooftop solar for example. Doesn't work for all buildings, but we are talking about the aggregate effect on the grid, which it does work for in most locales. In other locales, there are other solutions. You mention hydrogen. Pretty corrosive and explosive stuff, but maybe.
  • natch 5y ago
    Please stop downvoting the above comment. Sure, it is wrong thinking imho, but it is a doubt that a lot of people have, and it needs to be seen and addressed. If we just downvote questions like this into oblivion, it kills the discussion and people continue on with their misconceptions, which never get addressed.
    • rootusrootus 5y ago
      In my experience, many of the people who say things like this don't just have misconceptions, they have an axe to grind. In that case, preventing the spread of their misinformation may have more value than trying to 'educate' them.
      • natch 5y ago
        It's not so much to educate those who have an ax to grind, and I tend to agree on where (many of) these people are coming from. It's to allow everyone else to see under the open light how weak the ax is, and what a dull blade it has, and what poor metal it was forged out of, and how it was never a good ax to begin with. Instead of just saying (not that you directly said this, but downvotes kind of say it): "let's not talk about that."
        • rootusrootus 5y ago
          I think I agree with you, but I may have less faith in the ability of random people to get past the first argument and make it to the counterpoints. I'm probably being uncharitable; especially somewhere like HN.
    • ypcx 5y ago
      OP here. The second sentence came out all wrong and the downvotes are deserved. What I was trying to ponder, was - given the summer blackouts (in certain areas) due to people running their ACs (more than on average) - how do we plan to cope with the advent of EVs. So I did some googling[1] and apparently, until 2030 there's only 1 million EVs planned to hit the roads in the US, which is quite shocking given the dire trends of climate change and toxic pollution on this planet. Another interesting fact is that the costs of extending the power grid will be passed on to all its consumers in the form of increased rates (as it should, because if you don't drive an EV, you should be "taxed" on the extra pollution your car creates). [1] https://www.bcg.com/publications/2019/costs-revving-up-the-grid-for-electric-vehicles https://www.bcg.com/publications/2019/costs-revving-up-the-g...
  • rootusrootus 5y ago
    > If we tried to swich half the cars to electric overnight Let's not, then. The logistics of swapping 150 million cars in a single night would be a nightmare. Charging wouldn't be my first concern. On a more realistic note, even if we outlawed the sale of ICE cars today and mandated that every single new car hitting the road was electric, the required growth of the grid would be feasible. It would take quite a few years to replace the entire fleet.
• rbanffy 5y ago
  They don't lower the resistance - they just remove a lot of waste heat very quickly before the cable vaporizes. When I was reading the article, I was wondering what that kind of current would do to the poor batteries in the car and how would they get rid of the extra heat.
  • jacquesm 5y ago
    There are some interesting battery chemistries: https://en.wikipedia.org/wiki/Lithium-titanate_battery https://en.wikipedia.org/wiki/Lithium-titanate_battery Still not energy dense enough to replace Li-Ion but there are quite a few groups working on that problem.
    • rwmj 5y ago
      Supercaps would also work, although of course with even lower density (probably impractical for a useful car).
      • rbanffy 5y ago
        You can use the supercapacitors in the railguns for temporarily storing the incoming surge and pass it smoothly to the batteries. That’s a great excuse to have railguns on every car.
        • cogman10 5y ago
          super capacitors make more sense for the braking and acceleration. They aren't dense enough to really make any appreciable difference in charge time. They can be, however, dense enough to smooth out the power demands so you aren't trying to pull or push in too much power into the main battery during regular driving.
          • jacquesm 5y ago
            Wasn't there a rumor or even a factoid about one of the F1 teams using supercaps for their KERS?
• captainmuon 5y ago
  If the cable was the bottleneck, then you could half charging time by just using two cables. I used to wonder why nobody tried this.
  • jsilence 5y ago
    It is not only the cable from the station to the car, but also from the grid to the station. And so on.
  • cogman10 5y ago
    Funnily, that's exactly what the early Tesla Semis do. They have a charger aggregator which takes multiple supercharging stalls to charge one truck. The issue is, of course, not one of delivering the power, but rather that the battery chemistries we have today can't accept that much power without being damaged.
    • Symbiote 5y ago
      I've seen this on electric buses a few years ago (i.e actual production vehicles), but I don't know if it's still done.
• deelowe 5y ago
  What's the lower limit for a single rechargeable cell? That's the lower limit for the pack as well, if they can all be charged in parallel. I'm sure the thermal engineers would have fun dealing with that but it's possible in theory at least.