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It seems like it would be to expensive to build and maintain this kind of cabling over a significant portion of the highway, but it would be interesting to have

It seems like it would be to expensive to build and maintain this kind of cabling over a significant portion of the highway, but it would be interesting to have it over smaller sections so trucks can re-charge without stopping.

jessriedel 7y ago
Naively, the ability to re-charge without stopping seems of limited value. Given predictable routes and the existing network of specialized stops for trucks, I expect that battery swapping and overnight charging of trucks is sufficient, and does not require maintaining expensive overhead wiring infrastructure stretching over miles. Just consider what is going to require more hardware: a single battery swap station, or miles and miles of overhead wiring necessary to recharge a truck battery given known limits to battery charging speeds.
- Reason077 7y ago
  Battery swapping is an inefficient use of resources. Batteries are expensive assets and make up the bulk of the cost of an electric truck. You want to have all your batteries inside trucks, working as much as possible, not sitting around stored at swap stations waiting to be used. Fast charging infrastructure beats battery swapping, and recharge times aren’t really an issue. In Europe, truck drivers are required to take breaks every 4.5 hours anyway.
  - jessriedel 7y ago
    > You want to have all your batteries inside trucks, working as much as possible, not sitting around stored at swap stations waiting to be used. Batteries don't sit at swap stations just waiting to be used, they sit there charging. (The big difference is that the vehicle, which is also an expensive asset, doesn't have to be attached to them while doing this.) Stations will have the minimum number of batteries on hand to ensure there is always one available to swap in. Insofar as you need extra capacity to handle fluctations in usage, leading to charged batteries sitting around, you have a a strictly worse problem if the batteries are permanently attached to vehicles (since vehicle demand fluctuations don't go away, and you have the additional problem that you can't remove batteries from vehicles that aren't going to be used for a while). Another way to see this is that swappable batteries is just an extra ability; you can always charge the battery attached to the vehicle if you want. If you have a link to a technical argument for what you're trying to gesture at, I'd love to see it, but the argument you've given doesn't hold water. Arguments relating to the cost of the swapping infrastructure are at least plausible. > and recharge times aren’t really an issue. In Europe, truck drivers are required to take breaks every 4.5 hours anyway. In that case, there is no point to the overhead charging system discussed in the OP article.
    - Reason077 7y ago
      ”Stations will have the minimum number of batteries on hand to ensure there is always one available to swap in.” Therein lies the problem. You may be able to optimise your network, scheduling truck routes according to availability of swaps, etc. But it’s always going to require a substantially greater number of batteries than trucks. And for what gain? Time savings are zero-to-minimal, and fast charging is cheaper, easier, and more flexible than swapping. Also, truck batteries are going to be much bigger than car batteries. A long-range truck pack will weigh several tonnes. A station that can swap these quickly in a semi-automated way is likely to be a substantial, expensive undertaking.
      - netsharc 7y ago
        Trucks already have a mechanism to attach and detach their cargo trailers, I'd imagine any battery swap feature would use this as a starting point.
      - jessriedel 7y ago
        > But it’s always going to require a substantially greater number of batteries than trucks. I already addressed this is my comment. It's a loss that applies just as well to batteries that cannot be attached to vehicles, so it's not an argument against detachable batteries. > Also, truck batteries are going to be much bigger than car batteries. A long-range truck pack will weigh several tonnes. Stations already have massive underground infrastructures for dealing with fuel, which has an effective energy density that is less than a factor of two smaller than batteries. And unlike fuel, which must be stored on-site for the entire time between fuel shipments (~24 hours), you don't need to store a comparable number of batteries on site, just enough to have them continuously charging. > A station that can swap these quickly in a semi-automated way is likely to be a substantial, expensive undertaking. Putting in miles and miles of overhead charing capabilities is, I claim, significantly more expensive. But I'm not interested in having a detailed conversation on the expense of swapping machinery if we can't even agree on the simple point about utilization rates of swappable batteries being as least as large as non-swappable ones.
    - Reason077 7y ago
- Someone 7y ago
  Recharging from these wires may not even be necessary to make this economically viable. If a truck only needs to take power from batteries for the stretches it rides outside such highways, it can have much smaller and lighter batteries, significantly increasing its cargo carrying capacity.
  - jessriedel 7y ago
    I mean maybe, but the point of GhostVII's comment was to consider only stretches of overhead power that were just long enough to recharge batteries (because stretches long enough to keep trucks moving on their entire trip would be prohibitively expensive infrastructure).
mensetmanusman 7y ago
Near weighing stations/rest areas where they go slowly/park overnight...
Retric 7y ago
There is surprisingly little Highway Miles in most countries. The US interstate system is only 48,191 miles long. If this cost 1 million per mile per year to maintain that’s only 50 billion per year which is likely far less than the amount of fuel saved. A larger issue is top speed, this needs to work at 70MPH to be really useful. Though high speed electric trains demonstrate that should be possible.
- yodsanklai 7y ago
  Another issue is your electricity production. If it comes primarily from coal, I suppose you are better off with diesel trucks.
  - TeMPOraL 7y ago
    Actually no, you're not. It's easier and more efficient to filter out pollution at a power plant than in each car.
    - kaybe 7y ago
      And it's a lot easier to replace.
_visgean 7y ago
Well it has been built in rail networks that are as long as highways.

jessriedel 7y ago

Naively, the ability to re-charge without stopping seems of limited value. Given predictable routes and the existing network of specialized stops for trucks, I expect that battery swapping and overnight charging of trucks is sufficient, and does not require maintaining expensive overhead wiring infrastructure stretching over miles. Just consider what is going to require more hardware: a single battery swap station, or miles and miles of overhead wiring necessary to recharge a truck battery given known limits to battery charging speeds.

Reason077 7y ago
Battery swapping is an inefficient use of resources. Batteries are expensive assets and make up the bulk of the cost of an electric truck. You want to have all your batteries inside trucks, working as much as possible, not sitting around stored at swap stations waiting to be used. Fast charging infrastructure beats battery swapping, and recharge times aren’t really an issue. In Europe, truck drivers are required to take breaks every 4.5 hours anyway.
- jessriedel 7y ago
  > You want to have all your batteries inside trucks, working as much as possible, not sitting around stored at swap stations waiting to be used. Batteries don't sit at swap stations just waiting to be used, they sit there charging. (The big difference is that the vehicle, which is also an expensive asset, doesn't have to be attached to them while doing this.) Stations will have the minimum number of batteries on hand to ensure there is always one available to swap in. Insofar as you need extra capacity to handle fluctations in usage, leading to charged batteries sitting around, you have a a strictly worse problem if the batteries are permanently attached to vehicles (since vehicle demand fluctuations don't go away, and you have the additional problem that you can't remove batteries from vehicles that aren't going to be used for a while). Another way to see this is that swappable batteries is just an extra ability; you can always charge the battery attached to the vehicle if you want. If you have a link to a technical argument for what you're trying to gesture at, I'd love to see it, but the argument you've given doesn't hold water. Arguments relating to the cost of the swapping infrastructure are at least plausible. > and recharge times aren’t really an issue. In Europe, truck drivers are required to take breaks every 4.5 hours anyway. In that case, there is no point to the overhead charging system discussed in the OP article.
  - Reason077 7y ago
    ”Stations will have the minimum number of batteries on hand to ensure there is always one available to swap in.” Therein lies the problem. You may be able to optimise your network, scheduling truck routes according to availability of swaps, etc. But it’s always going to require a substantially greater number of batteries than trucks. And for what gain? Time savings are zero-to-minimal, and fast charging is cheaper, easier, and more flexible than swapping. Also, truck batteries are going to be much bigger than car batteries. A long-range truck pack will weigh several tonnes. A station that can swap these quickly in a semi-automated way is likely to be a substantial, expensive undertaking.
    - netsharc 7y ago
      Trucks already have a mechanism to attach and detach their cargo trailers, I'd imagine any battery swap feature would use this as a starting point.
    - jessriedel 7y ago
      > But it’s always going to require a substantially greater number of batteries than trucks. I already addressed this is my comment. It's a loss that applies just as well to batteries that cannot be attached to vehicles, so it's not an argument against detachable batteries. > Also, truck batteries are going to be much bigger than car batteries. A long-range truck pack will weigh several tonnes. Stations already have massive underground infrastructures for dealing with fuel, which has an effective energy density that is less than a factor of two smaller than batteries. And unlike fuel, which must be stored on-site for the entire time between fuel shipments (~24 hours), you don't need to store a comparable number of batteries on site, just enough to have them continuously charging. > A station that can swap these quickly in a semi-automated way is likely to be a substantial, expensive undertaking. Putting in miles and miles of overhead charing capabilities is, I claim, significantly more expensive. But I'm not interested in having a detailed conversation on the expense of swapping machinery if we can't even agree on the simple point about utilization rates of swappable batteries being as least as large as non-swappable ones.
  - Reason077 7y ago
Someone 7y ago
Recharging from these wires may not even be necessary to make this economically viable. If a truck only needs to take power from batteries for the stretches it rides outside such highways, it can have much smaller and lighter batteries, significantly increasing its cargo carrying capacity.
- jessriedel 7y ago
  I mean maybe, but the point of GhostVII's comment was to consider only stretches of overhead power that were just long enough to recharge batteries (because stretches long enough to keep trucks moving on their entire trip would be prohibitively expensive infrastructure).

mensetmanusman 7y ago

Near weighing stations/rest areas where they go slowly/park overnight...

Retric 7y ago

There is surprisingly little Highway Miles in most countries. The US interstate system is only 48,191 miles long. If this cost 1 million per mile per year to maintain that’s only 50 billion per year which is likely far less than the amount of fuel saved. A larger issue is top speed, this needs to work at 70MPH to be really useful. Though high speed electric trains demonstrate that should be possible.

yodsanklai 7y ago
Another issue is your electricity production. If it comes primarily from coal, I suppose you are better off with diesel trucks.
- TeMPOraL 7y ago
  Actually no, you're not. It's easier and more efficient to filter out pollution at a power plant than in each car.
  - kaybe 7y ago
    And it's a lot easier to replace.

_visgean 7y ago

Well it has been built in rail networks that are as long as highways.