Comment on Five-minute EV charging: CATL says "Hold my electrons and watch this"

• BussyCat@lemmy.world ⁨1⁩ ⁨day⁩ ago

  It doesn’t need to be, high voltage transmission lines can run 1000s of MW then you can use a transformer to step the voltage to what you need and then use a rectifier bridge to convert to DC.

  The problem I see is the effect of trying to turn on and off 1MW power from a grid could cause problems so the battery could work a bit as an expansion tank to smooth out grid power, so that you always charge it at 100KW and if you need to increase supply you can slowly increase your power draw without shocking the grid.

  At the end of the day I personally think 1MW charging is overkill and a 10 minute charge time is a perfectly reasonable goal

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  • AnUnusualRelic@lemmy.world ⁨13⁩ ⁨hours⁩ ago

    Couldn’t they have something like capacitor banks at the charging station? They’re not charging vehicles nonstop after all. I’m not sure what the efficiency loss would be, electricity isn’t my forte, maybe it’s a stupid idea.

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  • ExLisper@lemmy.curiana.net ⁨18⁩ ⁨hours⁩ ago

    I see couple other problems:

    • you need to put some of the chargers in the middle of nowhere (next to a highway, hundredths of km from big cities. in Spain for example there’s a lot of depopulated areas). Building all the infrastructure to get the power there will be very expensive
    • even in cities changing the grid like that can be very difficult. My office wanted to put 10 slow (20kW) chargers in the office and it took a year for the power company to make the necessary changes.
    • at a gas station it’s hard to break the gasoline supply. Individual pumps can break but the supply is very robust. If anything at the 1MW charger breaks (lines, transformer, converter) the entire things goes out of service and will take hours/days to fix. Building those charges to be as reliable as gas stations will be difficult and expensive.

    The charging times are not about how long do you have to wait while your car is charging but how many cars can you charge at peak hours. Last Easter in Spain there were huge lines to the charges because everyone was driving at the same time and there were simply not enough chargers. 5 min vs 10 min charging means the line is moving twice as fast.

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    • BussyCat@lemmy.world ⁨17⁩ ⁨hours⁩ ago

      For low travel areas slower charging and batteries make a lot more sense as the investment in ultra fast charging is not viable and I don’t see that changing

      I think regulatory inertia Is always going to be a problem but if we are regularly adding charging stations it will get faster as power companies have an incentive to build them and you get staff trained up on them

      Gas stations can still have single point failures for example if their underground tank gets contaminated or damaged and they don’t have a back up and electric doesn’t need to have single point failures you can run them in parallel with breakers able to isolate portions of the system and have redundant transformers

      EV works best if most people charge at home/work and people only charge in public if they don’t have the ability to do it at home or they are on a long drive. So you don’t need to meet the same cars per hour as gas stations.

      I don’t see a world where fast charging is as cheap as slower charging just due to increased losses and more expensive equipment so I believe having 10 500kw chargers would be a better investment than 6 1MW chargers even though technically the MW chargers have a larger throughput they are more expensive to produce/run and have more issues if for example 8 people arrive at once

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      • ExLisper@lemmy.curiana.net ⁨16⁩ ⁨hours⁩ ago

        Agree with everything (especially the 10 x 500kW > 6 x 1MW part), I’m not saying building out the infrastructure will not happen, I’m just saying that it will be difficult and what I see in real world is far from the ideal you’re describing. On any longer travel I have to pass through low travel areas. Entering cities to charge is impractical because getting in and out can take 0.5-1h. The chargers are still unreliable so planning a longer route is not easy. I have to carefully check the chargers maps, looking at the distances between each charger and possible backups. 99% of people are not going to do this. Until a big. reliable network of fast chargers exists they will just stick to gasoline cars (or protest if you force them to switch). And building such networks is a slow and expensive.

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  • LucidiaDiamond@lemm.ee ⁨23⁩ ⁨hours⁩ ago

    Why not use a large capacitor as a buffer. Would give peak power at the beginning of the charging cycle which is what you want anyway for quick turnaround.

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    • BussyCat@lemmy.world ⁨18⁩ ⁨hours⁩ ago

      Electricity is not my forte so correct me if I’m wrong but if you had a long gap in cars using the charger a capacitor would quickly become saturated. Which means you would need more wattage going to the capacitor at all times. Whereas with a battery if you have a car on a 5 minute charger with 5 minutes in between you could pretty easily run 500kW constantly to the battery and then as the battery dropped in level you could slowly ramp up the power draw

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• Buffalox@lemmy.world ⁨1⁩ ⁨day⁩ ago

  Charging this fast is always battery to battery, right?

  It’s DC but I think it’s from grid through inverters. And those inverters are quite expensive. So my guess is they can go on indefinitely.

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  • ExLisper@lemmy.curiana.net ⁨1⁩ ⁨day⁩ ago

    Interesting, I’ve found this quote:

    “Unlike regular EV chargers, these new high-powered units can’t simply be installed anywhere, as they demand substantial electrical capacity to operate at full capacity. They may require more direct access to high-voltage mains, limiting their deployment to locations with robust grid infrastructure.”

    I thought getting a 1MW connection to the grid is pretty much impossible for a charger. I wander if we’re going to see this in Europe.

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    • progandy@feddit.org ⁨1⁩ ⁨day⁩ ago

      There are multiple development projects for megawatt chargers with MCS plugs active in the EU.

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    • Buffalox@lemmy.world ⁨1⁩ ⁨day⁩ ago

      300 kW chargers are pretty common here (Denmark), I did a search, and the fastest I can find is 400kW. But they are rare, and I don’t think many cars can utilize that yet.
      I have no doubt that when cars that can handle 1MW become common, we will also get the chargers for them. But it will probably also be expensive to use.

      China doesn’t have 1MW yet either, BYD has just begun building them. The fastest Tesla supercharger here is 250 kW.

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      • ExLisper@lemmy.curiana.net ⁨1⁩ ⁨day⁩ ago

        Ionity has 300kW chargers in Spain but there are pretty rare. 50kW-100kW is most common here. Rolling out 1MW network will be very slow due to all the infrastructure it requires and judging by the prices of 150kW chargers, charging at 1MW speeds will probably be more expensive than gasoline. But in the end that’s the only way to actually replace gasoline cars so they will have to build it eventually. My guess would be 10-15 years before you can reliably (as in network big enough that you can easily find working chargers) charge at those speeds.

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    • sugar_in_your_tea@sh.itjust.works ⁨1⁩ ⁨day⁩ ago

      Why would it be impossible? A typical distribution power line is something in the range of 3MW, and that’s just the regular power lines running along the side of the road in your typical city. Larger power lines (i.e. long distance lines) have orders of magnitude higher voltage and, I assume, total power delivery.

      So something official like a large recharge station (i.e. converted gas station) could pretty reasonably support 1-2MW if needed, though they’d probably end up w/ local storage so they don’t spike power demand like crazy, and then recharge that storage w/ solar in the day and base load at night.

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