11 ms·

Can electric cars on the highway emulate plane-to-plane refueling?

47 points by jonbaer 7y ago

jccc 7y ago
Asking sincerely: Why should we not simply pull over to do this? Planes obviously are a different situation, but cars can easily just stop. While cool to imagine, it seems unnecessarily complicated and unsafe to do this in motion on the road. [Edit: The prof and his team are quite serious about it, so I assume there must be a reason and I'm actually curious what it might be.]
- irishcoffee 7y ago
  This is the correct question. Planes did it because they had to. Highly trained pilots execute in-air refueling. Not kids with their folks teslas.
- willis936 7y ago
  It seems like a valuable proposition if we threw out the existing paradigms of road transport. If we throw out concepts such as ownership of vehicles and fuel and treat all road vehicles as one system of controlled individual elements, you could envision is a more efficient solution. Traffic jams would be lessened, trip times would be shortened, total fuel usage would go down, etc. On road-fueling would be one element in a world like this: road based freight delivery could run without stopping by using vehicles expected to have short journies to refuel the trucks along the way. This is all to define a hypothetical new paradigm in road transport and to quantify its potential consequences (good and bad). I had not thought about on-road refueling before and I think there is good value in pointing it out. We're not at the point where we're seriously charting a course to world like this, but we need to know what the world looks like before we can start to do that.
  - bdamm 7y ago
    Many things are valuable if we throw out the constraints of dealing with existing reality. Even then I'm not sure it is valuable; roads suffer from lack of maintenance already. If anything we should be looking at how to make roads less expensive. Having autonomous vehicles disperse their weight to reduce prevalence of potholes, for example.
    - willis936 7y ago
      Right, and that is one thing to weight for when choosing the behavior of the system. While the article in question doesn't explicitly say this, I think these seemingly impractical solutions add to the theoretical toolkit that we can use to shape a road utopia, if society ever agrees on what that would look like. If society does ever agree on a road utopia and then consider it worthwhile to pursue, it will be valuable to have these ideas laid out. Perhaps they are useless today, but they motivate this idea. If they weren't proposed then the possibility of a future road utopia is entirely impossible.
  - lmilcin 7y ago
    If we are "throwing out the existing paradigms of road transport” then why not throw out roads completely. Rails are way more efficient.
    - loa_in_ 7y ago
      That's true only if they reach all destinations
      - jakecopp 7y ago
        Yep, they do already! The future is here, just not evenly distributed (to the US :P) https://www.openrailwaymap.org/?lang=null&lat=48.21003212234042&lon=8.28369140625&zoom=5&style=standard https://www.openrailwaymap.org/?lang=null&lat=48.21003212234...
        tdhoot 7y ago
        Can I go from my house to my friends house using only rails? My house to the supermarket? Not all pairwise points are connected by rails, while they generally are by roads.
        lmilcin 7y ago
        The post is about long distance travel.
        tdhoot 6y ago
        My point still applies.
  - rdrock 7y ago
    An old-new paradigm of road transport, https://en.wikipedia.org/wiki/The_Roads_Must_Roll https://en.wikipedia.org/wiki/The_Roads_Must_Roll makes for a good read.
- yawgmoth 7y ago
  The non-serious answer is that we need to charge while driving to best emulate F-Zero https://youtu.be/BIe4AvKLSa4?t=217 https://youtu.be/BIe4AvKLSa4?t=217
  - nitwit005 7y ago
    That was a mid-air repair of another flying vehicle.
    - ta17711771 7y ago
      F-Zero & F-Zero X allowed you to use the shield bar as boost-fuel as well.
- baltimore 7y ago
  Because charging takes much longer than filling up with gas. If someone is willing to pay a premium for charging while driving to reduce total trip time, that's a business opportunity.
  - goodcanadian 7y ago
    This is often said, but I am not so sure. Fast-charging takes somewhat longer than filling with gasoline/petrol, but I usually also want a bathroom and coffee break. I can easily do that while my car is charging. That is not really true while dispensing gasoline. It is not so obvious to me that I am losing out time-wise. This is not idle speculation. I own an electric car. Furthermore, the vast majority of my charging occurs at home, over night. The total amount time I have saved by not having to visit gas stations for literally months is significant.
    - vonmoltke 7y ago
      > Fast-charging takes somewhat longer than filling with gasoline/petrol, but I usually also want a bathroom and coffee break. It's more than "somewhat". I can put over 400 highway miles of range into my vehicle in five minutes with a gas pump. It takes 30 minutes to put half that into an EV. I don't want to stop for half an hour every 200 miles. > This is not idle speculation. I own an electric car. Furthermore, the vast majority of my charging occurs at home, over night. The total amount time I have saved by not having to visit gas stations for literally months is significant. It sounds like you don't have many days where your driving exceeds the range capacity of your vehicle. The technology in the article, and the post you are responding to, are in the context of long-distance highway travel. It's for cases where a vehicle must be recharged in the middle of a trip, even when it starts with a full battery.
      - tonyedgecombe 7y ago
        * I don't want to stop for half an hour every 200 miles.* Ugh, I don't even want to drive 200 miles in a day if I can avoid it.
      - 7y ago
- valuearb 7y ago
  Commercial planes don’t even do midair refueling, because it’s expensive and dangerous.
pjkundert 7y ago
One of the next obvious steps for self-driving vehicles is “flocking” or drafting; this is an almost trivial problem once two or more vehicles are autonomously locked within a few inches of each other.
- jstanley 7y ago
  If you have a car only a few inches behind you and you spot a problem and need to emergency brake, you can't actually start braking until the car behind has started braking, otherwise the car behind will crash into the back of you. If you have 3 cars in a row, and the first car spots a problem, it can't start braking until after the 2nd car has started, but the 2nd car can't start braking until after the 3rd car has started. It gets linearly more dangerous as more cars are added. Not saying it can't be done, but the problem is more subtle than just working out how to stop the cars from crashing into each other at speed: they also need to be able to brake in emergencies without crashing into each other. Possibly the way to do it would be to mechanically couple the cars like a train, so that it is safe for the one in front to start braking earlier than the one behind, albeit with reduced performance.
  - cheerlessbog 7y ago
    The idea is predicated on autonomous control and presumably the vehicles communicate in real time...they all brake together at the delta V of the least capable member.
    - jstanley 7y ago
      The "real time" control loop between the sensor on one car and the brakes on the same car is much tighter than that between the sensor on this car and the brakes on another car and then feedback from the other car that braking has started. I don't actually know how long it takes between the computer deciding to brake and the car actually starting to slow down, but I expect you can't just throw out a message saying "I'm braking immediately" and start braking without any kind of confirmation that the message was received, and expect it to be OK. But maybe you can afford to wait for a confirmation? The speed of light is pretty fast, and you're not transmitting that many bytes. Especially if you consider that a human could easily take 200 milliseconds to react to something even if it's really paying attention. You could request a braking confirmation from the other side of the Atlantic and still come out ahead!
zackkatz 7y ago
This reminds me of old Popular Science magazines promising a future of unrealized technology. I do not think this is the future. But it’s something I’d like to see in a sci-fi movie.
nicoburns 7y ago
Wouldn't it make more sense to build the charging into the road?
- umvi 7y ago
  We could make the road out of interlocking hexagonal solar panels
  - cheerlessbog 7y ago
    This was done as you probably know [1] but it's not clear that the road surface is a good place for solar panels. They get dirty and damaged. It's certainly orthogonal to charging vehicles on the road, given we know how to transmit power already. [1] https://www.google.com/amp/s/www.theverge.com/platform/amp/2016/12/22/14055756/solar-panel-road-electricity-france-normandy https://www.google.com/amp/s/www.theverge.com/platform/amp/2...
    - cheerlessbog 7y ago
      Indeed [2] BTW when searching on Google it is quite obnoxious that it doesn't navigate to the actual URL but instead prefixes it with Google.. [2] https://www.google.com/amp/s/www.businessinsider.com/first-solar-road-france-failure-photos-2019-8%3famp https://www.google.com/amp/s/www.businessinsider.com/first-s...
    - umvi 7y ago
      Are you saying charge vehicles on the road using i.e. inductors underneath the road?
bob33212 7y ago
The only good options are: 1. Make much more rapid charging possible on the cars much closer to the interstate. 2. Add a electrified metal rail to the road so that the cars can charge like a subway car.
ashtonkem 7y ago
Why bother? With top line EV ranges reaching close to 400 miles, after that amount of time I need to get out of the car. If you want people to be able travel huge distances cleanly without stopping, then what you’re actually looking for is a train.
- willis936 7y ago
  What about an autonomous semitruck that could run 24 hours a day except for unloading/reloading cargo, refueling, and maintenance?
  - ashtonkem 7y ago
    Trains. The fact that long haul semi trucks are a thing is a failure of infrastructure. Edit: as some have pointed out, it’s more a failure of policy.
    - willis936 7y ago
      Trains are large and inflexible. Short of having a city-block resolution freight train network at every population center, you'll need something flexible for the last mile of delivery.
      - ashtonkem 7y ago
        You’re misunderstanding. The only reason why you’d need on-road recharging for hypothetical autonomous semi trucks is if they’re regularly traveling outside the range of their batteries, which is probably in the 400-500mi range. In a well designed infrastructure system, that shouldn’t happen often. Instead the hops of hundreds of miles should be handled by trains, leaving semi trucks for the last dozens of miles from train hub to area of need. Some long haul trucking will happen, but it should be a slim minority of cases.
        dsfyu404ed 7y ago
        Adding an extra step (rail hub to short haul truck transition, potentially at both ends of the trip) adds cost. This cost is (and will be for the foreseeable future) less than having the less efficient semi-truck do the entire trip at least for the kinds of loads that are currently carried by semi-truck. JIT inventory systems also don't play nice with rail.
patall 7y ago
Can anyone explain what happened to battery swapping. A few years ago there was this Tesla show where they swapped three cars in the time it took to refuel a normal ICE automotive. But after that nothing happened. I know it is difficult to handle when you do not own the battery but I would guess 90% of private long distance trips are return trips, so you could swap batteries at your trusted former gas station every 200 miles and then on the way back home do the same and get your old battery back at your last stop and keep that pack for all your short day to day trips. But somehow, this idea seems to be 100% abandoned. Edit: Follow up conspiracy: Could it actually be because the battery is the one component of an EV that degrades the fastest and thus cars would last much longer (and no manufacturer would want that) if you could just swap the main battery every 100.000 miles or so?
- ravenstine 7y ago
  That's because it's not "cool". We wanted our flying cars, so if we aren't getting those, we at least want our cars to do wild and unbelievable things like flock together and fuel each other like jet planes. Who's going to invest in battery swapping technology? It's effectively a solved problem and not exciting.
- matz1 7y ago
  Probably the same reason why smartphone battery is not swappable. For various reason we don't have swappable smartphone battery even though it is technically much easier problem to solve.
  - ravenstine 7y ago
    What reason would that be? I always assumed that was because of the pursuit of slimmer phones and to discourage repair.
    - Retric 7y ago
      It’s also a more complex and expensive. Swapping cellphone batteries means you need to own another battery which few people did once capacity increased. With cellphones people that want a swappable battery can just get an external battery pack but most people can simply recharge daily.
ppod 7y ago
Maybe special powerful cars that are constantly charged could drag others along a fixed line in a kind of "train".
mmaunder 7y ago
I’m assuming very high power transmission in short period of time. Thus moderate amps and very high voltage or you’ll need thick cables.
jsjohnst 7y ago
I see no problems at all with being magnetically coupled via an extended probe to another car transferring high voltage and/or current while driving at highway speeds, none what so ever...
viburnum 7y ago
Replacing highways with trains for most trips is more sustainable.
letitbeirie 7y ago
Emulating plane-to-plane refueling entails all sorts of system dynamics problems because of the untrained human driver in the mix. Wouldn't it be a lot easier (and likely cheaper in the long run) to emulate overhead line-to-train power transfer? Seems like "transfer of electricity into an (ideally) land-bound vehicle from its infrastructure" would be a more closely related problem than "transfer of fluid from one airborne aircraft to another."
toss1 7y ago
I've been thinking for years that fully-automated platooning / drafting should be a good option for self-driving cars. Run it via an app, cars make themselves available for drafting, others nearby sign up, they all line up and save energy. Could be a nice feature for Tesla, or a competitor, to augment the value of being in their network. Obviously, this would rely on both self-driving and car-to-car communications to ensure simultaneous braking, acceleration, etc. to avoid accordion effect and chain-reaction collisions. Charge-sharing as in this article could be a nice addition too. Also seems most plausible to automatically pay for shared charge in credits of some sort, or cash through the app. My biggest question is whether the shared charge would be sufficiently useful in comparison to the cost/maintenance of the extra moving parts. Seems like induction power&charging in sections of road could be more effective.
nullsmack 7y ago
Why not just have overhead lines that you can attach to when you need a charge? Do it like the street cars. Or have something like a railroad you can drive up onto and then it charges you while you're traveling over it.
spiritplumber 7y ago
I think it's called a train...
Someone 7y ago
I think http://eptender.com/en/battery-tender-2-2 http://eptender.com/en/battery-tender-2-2 (renting a battery in a small trailer to extend a car’s range, potentially dropping it off at a different place from the one you picked it up) has more chance of succeeding In the market.
lmilcin 7y ago
Seriously doubt fast charging a battery of running car from battery of another running car.
simonblack 7y ago
Why do that? Incorporate a charging loop into the road. Better still, throw away those heavy and toxic batteries and just collect the car's power directly from the road.
- PhantomGremlin 7y ago
  What's the efficiency on something like that? What's the cost of tearing up every single highway in existence to add a charging loop?
munsters 7y ago
This seems like it would only work if you're able to stay bumper to bumper with the charging car for 30+ minutes. You'd have to be traveling a very long distance along the same route (and, the charging car's destination MUST be before it runs out of power after transferring its power). What are the odds of that happening, on a reliable basis? At that scenario, it seems more sensible to install overhead wires (or underground) along freeways for long distance travel.

47 points by jonbaer 7y ago

jccc 7y ago

Asking sincerely: Why should we not simply pull over to do this? Planes obviously are a different situation, but cars can easily just stop. While cool to imagine, it seems unnecessarily complicated and unsafe to do this in motion on the road. [Edit: The prof and his team are quite serious about it, so I assume there must be a reason and I'm actually curious what it might be.]

irishcoffee 7y ago
This is the correct question. Planes did it because they had to. Highly trained pilots execute in-air refueling. Not kids with their folks teslas.
willis936 7y ago
It seems like a valuable proposition if we threw out the existing paradigms of road transport. If we throw out concepts such as ownership of vehicles and fuel and treat all road vehicles as one system of controlled individual elements, you could envision is a more efficient solution. Traffic jams would be lessened, trip times would be shortened, total fuel usage would go down, etc. On road-fueling would be one element in a world like this: road based freight delivery could run without stopping by using vehicles expected to have short journies to refuel the trucks along the way. This is all to define a hypothetical new paradigm in road transport and to quantify its potential consequences (good and bad). I had not thought about on-road refueling before and I think there is good value in pointing it out. We're not at the point where we're seriously charting a course to world like this, but we need to know what the world looks like before we can start to do that.
- bdamm 7y ago
  Many things are valuable if we throw out the constraints of dealing with existing reality. Even then I'm not sure it is valuable; roads suffer from lack of maintenance already. If anything we should be looking at how to make roads less expensive. Having autonomous vehicles disperse their weight to reduce prevalence of potholes, for example.
  - willis936 7y ago
    Right, and that is one thing to weight for when choosing the behavior of the system. While the article in question doesn't explicitly say this, I think these seemingly impractical solutions add to the theoretical toolkit that we can use to shape a road utopia, if society ever agrees on what that would look like. If society does ever agree on a road utopia and then consider it worthwhile to pursue, it will be valuable to have these ideas laid out. Perhaps they are useless today, but they motivate this idea. If they weren't proposed then the possibility of a future road utopia is entirely impossible.
- lmilcin 7y ago
  If we are "throwing out the existing paradigms of road transport” then why not throw out roads completely. Rails are way more efficient.
  - loa_in_ 7y ago
    That's true only if they reach all destinations
    - jakecopp 7y ago
      Yep, they do already! The future is here, just not evenly distributed (to the US :P) https://www.openrailwaymap.org/?lang=null&lat=48.21003212234042&lon=8.28369140625&zoom=5&style=standard https://www.openrailwaymap.org/?lang=null&lat=48.21003212234...
      - tdhoot 7y ago
        Can I go from my house to my friends house using only rails? My house to the supermarket? Not all pairwise points are connected by rails, while they generally are by roads.
        lmilcin 7y ago
        The post is about long distance travel.
        tdhoot 6y ago
        My point still applies.
- rdrock 7y ago
  An old-new paradigm of road transport, https://en.wikipedia.org/wiki/The_Roads_Must_Roll https://en.wikipedia.org/wiki/The_Roads_Must_Roll makes for a good read.
yawgmoth 7y ago
The non-serious answer is that we need to charge while driving to best emulate F-Zero https://youtu.be/BIe4AvKLSa4?t=217 https://youtu.be/BIe4AvKLSa4?t=217
- nitwit005 7y ago
  That was a mid-air repair of another flying vehicle.
  - ta17711771 7y ago
    F-Zero & F-Zero X allowed you to use the shield bar as boost-fuel as well.
baltimore 7y ago
Because charging takes much longer than filling up with gas. If someone is willing to pay a premium for charging while driving to reduce total trip time, that's a business opportunity.
- goodcanadian 7y ago
  This is often said, but I am not so sure. Fast-charging takes somewhat longer than filling with gasoline/petrol, but I usually also want a bathroom and coffee break. I can easily do that while my car is charging. That is not really true while dispensing gasoline. It is not so obvious to me that I am losing out time-wise. This is not idle speculation. I own an electric car. Furthermore, the vast majority of my charging occurs at home, over night. The total amount time I have saved by not having to visit gas stations for literally months is significant.
  - vonmoltke 7y ago
    > Fast-charging takes somewhat longer than filling with gasoline/petrol, but I usually also want a bathroom and coffee break. It's more than "somewhat". I can put over 400 highway miles of range into my vehicle in five minutes with a gas pump. It takes 30 minutes to put half that into an EV. I don't want to stop for half an hour every 200 miles. > This is not idle speculation. I own an electric car. Furthermore, the vast majority of my charging occurs at home, over night. The total amount time I have saved by not having to visit gas stations for literally months is significant. It sounds like you don't have many days where your driving exceeds the range capacity of your vehicle. The technology in the article, and the post you are responding to, are in the context of long-distance highway travel. It's for cases where a vehicle must be recharged in the middle of a trip, even when it starts with a full battery.
    - tonyedgecombe 7y ago
      * I don't want to stop for half an hour every 200 miles.* Ugh, I don't even want to drive 200 miles in a day if I can avoid it.
    - 7y ago
valuearb 7y ago
Commercial planes don’t even do midair refueling, because it’s expensive and dangerous.

pjkundert 7y ago

One of the next obvious steps for self-driving vehicles is “flocking” or drafting; this is an almost trivial problem once two or more vehicles are autonomously locked within a few inches of each other.

jstanley 7y ago
If you have a car only a few inches behind you and you spot a problem and need to emergency brake, you can't actually start braking until the car behind has started braking, otherwise the car behind will crash into the back of you. If you have 3 cars in a row, and the first car spots a problem, it can't start braking until after the 2nd car has started, but the 2nd car can't start braking until after the 3rd car has started. It gets linearly more dangerous as more cars are added. Not saying it can't be done, but the problem is more subtle than just working out how to stop the cars from crashing into each other at speed: they also need to be able to brake in emergencies without crashing into each other. Possibly the way to do it would be to mechanically couple the cars like a train, so that it is safe for the one in front to start braking earlier than the one behind, albeit with reduced performance.
- cheerlessbog 7y ago
  The idea is predicated on autonomous control and presumably the vehicles communicate in real time...they all brake together at the delta V of the least capable member.
  - jstanley 7y ago
    The "real time" control loop between the sensor on one car and the brakes on the same car is much tighter than that between the sensor on this car and the brakes on another car and then feedback from the other car that braking has started. I don't actually know how long it takes between the computer deciding to brake and the car actually starting to slow down, but I expect you can't just throw out a message saying "I'm braking immediately" and start braking without any kind of confirmation that the message was received, and expect it to be OK. But maybe you can afford to wait for a confirmation? The speed of light is pretty fast, and you're not transmitting that many bytes. Especially if you consider that a human could easily take 200 milliseconds to react to something even if it's really paying attention. You could request a braking confirmation from the other side of the Atlantic and still come out ahead!

zackkatz 7y ago

This reminds me of old Popular Science magazines promising a future of unrealized technology. I do not think this is the future. But it’s something I’d like to see in a sci-fi movie.

nicoburns 7y ago

Wouldn't it make more sense to build the charging into the road?

umvi 7y ago
We could make the road out of interlocking hexagonal solar panels
- cheerlessbog 7y ago
  This was done as you probably know [1] but it's not clear that the road surface is a good place for solar panels. They get dirty and damaged. It's certainly orthogonal to charging vehicles on the road, given we know how to transmit power already. [1] https://www.google.com/amp/s/www.theverge.com/platform/amp/2016/12/22/14055756/solar-panel-road-electricity-france-normandy https://www.google.com/amp/s/www.theverge.com/platform/amp/2...
  - cheerlessbog 7y ago
    Indeed [2] BTW when searching on Google it is quite obnoxious that it doesn't navigate to the actual URL but instead prefixes it with Google.. [2] https://www.google.com/amp/s/www.businessinsider.com/first-solar-road-france-failure-photos-2019-8%3famp https://www.google.com/amp/s/www.businessinsider.com/first-s...
  - umvi 7y ago
    Are you saying charge vehicles on the road using i.e. inductors underneath the road?

bob33212 7y ago

The only good options are: 1. Make much more rapid charging possible on the cars much closer to the interstate. 2. Add a electrified metal rail to the road so that the cars can charge like a subway car.

ashtonkem 7y ago

Why bother? With top line EV ranges reaching close to 400 miles, after that amount of time I need to get out of the car. If you want people to be able travel huge distances cleanly without stopping, then what you’re actually looking for is a train.

willis936 7y ago
What about an autonomous semitruck that could run 24 hours a day except for unloading/reloading cargo, refueling, and maintenance?
- ashtonkem 7y ago
  Trains. The fact that long haul semi trucks are a thing is a failure of infrastructure. Edit: as some have pointed out, it’s more a failure of policy.
  - willis936 7y ago
    Trains are large and inflexible. Short of having a city-block resolution freight train network at every population center, you'll need something flexible for the last mile of delivery.
    - ashtonkem 7y ago
      You’re misunderstanding. The only reason why you’d need on-road recharging for hypothetical autonomous semi trucks is if they’re regularly traveling outside the range of their batteries, which is probably in the 400-500mi range. In a well designed infrastructure system, that shouldn’t happen often. Instead the hops of hundreds of miles should be handled by trains, leaving semi trucks for the last dozens of miles from train hub to area of need. Some long haul trucking will happen, but it should be a slim minority of cases.
      - dsfyu404ed 7y ago
        Adding an extra step (rail hub to short haul truck transition, potentially at both ends of the trip) adds cost. This cost is (and will be for the foreseeable future) less than having the less efficient semi-truck do the entire trip at least for the kinds of loads that are currently carried by semi-truck. JIT inventory systems also don't play nice with rail.

patall 7y ago

Can anyone explain what happened to battery swapping. A few years ago there was this Tesla show where they swapped three cars in the time it took to refuel a normal ICE automotive. But after that nothing happened. I know it is difficult to handle when you do not own the battery but I would guess 90% of private long distance trips are return trips, so you could swap batteries at your trusted former gas station every 200 miles and then on the way back home do the same and get your old battery back at your last stop and keep that pack for all your short day to day trips. But somehow, this idea seems to be 100% abandoned. Edit: Follow up conspiracy: Could it actually be because the battery is the one component of an EV that degrades the fastest and thus cars would last much longer (and no manufacturer would want that) if you could just swap the main battery every 100.000 miles or so?

ravenstine 7y ago
That's because it's not "cool". We wanted our flying cars, so if we aren't getting those, we at least want our cars to do wild and unbelievable things like flock together and fuel each other like jet planes. Who's going to invest in battery swapping technology? It's effectively a solved problem and not exciting.
matz1 7y ago
Probably the same reason why smartphone battery is not swappable. For various reason we don't have swappable smartphone battery even though it is technically much easier problem to solve.
- ravenstine 7y ago
  What reason would that be? I always assumed that was because of the pursuit of slimmer phones and to discourage repair.
  - Retric 7y ago
    It’s also a more complex and expensive. Swapping cellphone batteries means you need to own another battery which few people did once capacity increased. With cellphones people that want a swappable battery can just get an external battery pack but most people can simply recharge daily.

ppod 7y ago

Maybe special powerful cars that are constantly charged could drag others along a fixed line in a kind of "train".

mmaunder 7y ago

I’m assuming very high power transmission in short period of time. Thus moderate amps and very high voltage or you’ll need thick cables.

jsjohnst 7y ago

I see no problems at all with being magnetically coupled via an extended probe to another car transferring high voltage and/or current while driving at highway speeds, none what so ever...

viburnum 7y ago

Replacing highways with trains for most trips is more sustainable.

letitbeirie 7y ago

Emulating plane-to-plane refueling entails all sorts of system dynamics problems because of the untrained human driver in the mix. Wouldn't it be a lot easier (and likely cheaper in the long run) to emulate overhead line-to-train power transfer? Seems like "transfer of electricity into an (ideally) land-bound vehicle from its infrastructure" would be a more closely related problem than "transfer of fluid from one airborne aircraft to another."

toss1 7y ago

I've been thinking for years that fully-automated platooning / drafting should be a good option for self-driving cars. Run it via an app, cars make themselves available for drafting, others nearby sign up, they all line up and save energy. Could be a nice feature for Tesla, or a competitor, to augment the value of being in their network. Obviously, this would rely on both self-driving and car-to-car communications to ensure simultaneous braking, acceleration, etc. to avoid accordion effect and chain-reaction collisions. Charge-sharing as in this article could be a nice addition too. Also seems most plausible to automatically pay for shared charge in credits of some sort, or cash through the app. My biggest question is whether the shared charge would be sufficiently useful in comparison to the cost/maintenance of the extra moving parts. Seems like induction power&charging in sections of road could be more effective.

nullsmack 7y ago

Why not just have overhead lines that you can attach to when you need a charge? Do it like the street cars. Or have something like a railroad you can drive up onto and then it charges you while you're traveling over it.

spiritplumber 7y ago

I think it's called a train...

Someone 7y ago

I think http://eptender.com/en/battery-tender-2-2 http://eptender.com/en/battery-tender-2-2 (renting a battery in a small trailer to extend a car’s range, potentially dropping it off at a different place from the one you picked it up) has more chance of succeeding In the market.

lmilcin 7y ago

Seriously doubt fast charging a battery of running car from battery of another running car.

simonblack 7y ago

Why do that? Incorporate a charging loop into the road. Better still, throw away those heavy and toxic batteries and just collect the car's power directly from the road.

PhantomGremlin 7y ago
What's the efficiency on something like that? What's the cost of tearing up every single highway in existence to add a charging loop?

munsters 7y ago

This seems like it would only work if you're able to stay bumper to bumper with the charging car for 30+ minutes. You'd have to be traveling a very long distance along the same route (and, the charging car's destination MUST be before it runs out of power after transferring its power). What are the odds of that happening, on a reliable basis? At that scenario, it seems more sensible to install overhead wires (or underground) along freeways for long distance travel.