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

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

#51

Post by brownbat »

ashtonkem wrote: post #22
willis936 wrote: post #21

Earlier quoted context omitted.

What about an autonomous semitruck that could run 24 hours a day except for unloading/reloading cargo, refueling, and maintenance?

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.

Trains are far more efficient, less subsidized, safer, less polluting...

https://grist.org/article/freight-trains-19th-century-techno...

Even if you electrify trucks the tire and brake wear and road degradation contribute an enormous amount of PM 2.5.

Sure you'll need trucks for the last mile but every ton of freight we can move to rails or waterways is a victory for humanity.

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

#52

Post by ashtonkem »

dsfyu404ed wrote: post #41
ashtonkem wrote: post #31

Earlier quoted context omitted.

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…

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.

Semi trucks are cheaper because they receive a $125B+ yearly subsidy in the form of road maintenance. Semi trucks do 99% of the damage to our public roads, but only pay 35% of the cost.

I suspect that rail would be much more price competitive if we took that subsidy away.

You’re right about JIT, but we’re also seeing the downsides of JIT infrastructure during this pandemic. I suspect that we’ll see a push for more redundancy in our supply chain for reasons completely unrelated to trucks vs. trains.

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

#53

Post by ztakeo »

patall wrote: post #26

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 2…

Well if you want to see one way the battery swapping model can fail work, check out the book Totaled, which is about the Israeli EV startup Better Place that tried battery swapping before Tesla was a thing. Granted there were a lot of complicating factors that may not apply in the Tesla case (securing battery swapping locations in Israel came with specific challenges), but it may provide some insight.

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

#55

Post by SketchySeaBeast »

Retric wrote: post #46
ravenstine wrote: post #38

Earlier quoted context omitted.

What reason would that be? I always assumed that was because of the pursuit of slimmer phones and to discourage repair.

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.

Hmmm... is this not also an option with an electric car? A "long distance" battery pack trailer of some sort? Lose some sleekness, but gain a ton in utility, and storage space for those long trips.

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

#57

Post by ianai »

NickM wrote: post #39
patall wrote: post #26

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 2…

It was abandoned because fast charging stations keep improving, and are much simpler and cheaper to operate than battery swap stations. It's already at the point where you can take a 400-500 mile road trip in a Model 3 with maybe a single twenty minute charging stop, which is just not that much extra time, and most people like to take a short break every few hours anyway. I suspect Tesla knew this would probably happ…

I’d still like to be able to tow a battery behind me for extended trips.

I don’t know how running the AC impacts range, I would like to know. Places with extreme weather and major population centers can make an otherwise short drive really taxing on resources through ac use or just being stuck in place for extended periods of time. Like how peak LV traffic can turn a 15 min drive into a 50 minute drive in 120f+ heat.

Tow-able batteries would make wide use cases like apartments more viable too.

Edit-typo

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

#58

Post by mgr86 »

amirhirsch wrote: post #50
NickM wrote: post #39

Earlier quoted context omitted.

It was abandoned because fast charging stations keep improving, and are much simpler and cheaper to operate than battery swap stations. It's already at the point where you can take a 400-500 mile road trip in a Model 3 with maybe a single twenty minute charging stop, which is just not that much extra time, and most people like to take a short break every few hours anyway. I suspect Tesla knew this would probably happ…

A car with a 40 mile range would be cheaper to buy, and a lot lighter so also more efficient. You could swap in a 400 mile battery when you actually need it.

The problem I have with the 40 mile range is that is highly dependent on

1. temperature. Extreme cold lowers range 2. topography. Inclines can drain a battery quickly. Declines can add range. 3. driving style. Do you have a lead foot? 4. Driving type. Are you on a highway?

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

#59

Post by vangelis »

willis936 wrote: post #21
ashtonkem wrote: post #17

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.

What about an autonomous semitruck that could run 24 hours a day except for unloading/reloading cargo, refueling, and maintenance?

A diesel electric duorail truck would be great for large freight loads.

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

#60

Post by NickM »

nradov wrote: post #29
cheerlessbog wrote: post #10

Earlier quoted context omitted.

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.

Braking delta V depends on many variables such as mechanical condition, component temperature, road surface friction, etc and is thus difficult to predict to that level of precision. Even with real-time communications, if the vehicle in front slows less than expected due to hitting a pothole or something then the vehicles behind are going to have to react damn fast to avoid a collision. It might be achievable on cert…

Yeah all good points, and just to add, there's also the challenge of maintaining perfectly reliable and low-latency communications over any sort of wireless medium in a variety of unpredictable outdoor conditions.
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