If nearly all the savings is from reducing wind resistance, by drafting,
then the rails aren't really needed. We could build more expensive
infrastructure, but a cheaper solution is often better. In other words,
the focus should be on making drafting possible, not reducing rolling
resistance.
On wikipedia, one estimate for Teslas semi battery is 11800 kg, or more
than 20 tons. So, yes, a lot of weight. So, non battery power could
help. But it doesn't have to be rails. Centenaries would be much less
expensive to construct. Still, my guess is the long term cheapest
solution is the large battery. Over time, they will get cheaper and
lighter.
The biggest issue is emergencies. Even with a restricted lane, things
happen. If it's not completely separated, someone can drift in. Even if
only segments near exits have separation gaps, you still need to plan
for incursions. And even without incursions, a truck may suddenly have a
mechanical issue. In theory, I suppose this last case could be handled
by rapid reaction of the following vehicles. If you do a completely
restricted lane with it's own exits, the risk of emergencies would
drastically be reduced.
Peri
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------ Original Message ------
From: e...@vanderwal.us
To: "Peri Hartman" <pe...@kotatko.com>; "Electric Vehicle Discussion
List" <ev@lists.evdl.org>
Sent: 03-Dec-20 5:27:50 PM
Subject: Re: [EVDL] 'All's not well with UK public charging' / Autonomy
What kind of emergency? This is a "restricted" lane, so the only vehicles that
should be there are other vehicles on rails, so they can't go any faster than the one in
front of them. They can use adaptive cruise to maintain spacing, or even better some
kind of peer to peer network to coordinate their speed as well as entry/exit from the
lane.
As for using the rails for power, I'm not sure you are considering HOW many
batteries it would take to power a semi-tractor trailer rig. Air resistance is
proba bly over 90% of the energy requirement, switching to rails saves energy,
but less than 10%.
By my calculations each truck will require roughly 1 ton of Li-Ion batteries to
go 100 miles. To go 500 miles, it would need 5 tons, in addition to 5 tons of
cargo it can't carry, 5 tons of batteries is a LOT.
Using powered rails means they never need to stop to recharge. Since they
don't have to worry about driving around vehicles, etc. You won't need a driver
when it's on the rails, so even if you dont use autonymous trucks, the drive
can sleep while it's on the rails. With powered rails the truck only needs
enough batteries to get to/from the highway, 1 ton will probably be sufficient
(since it can charge them while on the rails)
December 3, 2020 2:25 PM, "Peri Hartman via EV" <ev@lists.evdl.org> wrote:
Very interesting idea. Would it be possible to design something that allows
that transition: to and
from rails ? It would need to be able to make the switch in a few tenths of a
second in order to
respond to emergencies. I've seen the track work trucks which have rubber
tires and steel wheels
that can be lowered, but they don't have quick action. Maybe a similar
mechanism could work,
though.
As for electrifying, that sounds unnecessary. True, there would be a lot of
wind resistance eating
up energy, but overall the efficiency should still go up dramatically and we
are already reaching
the economic point of using a large battery for long hauls. Or, am I wrong on
this: is the majority
of energy, at 70mph, used to push wind ?
Another consideration: with good "autopilot" software, drafting becomes
possible. That means a
series of trucks could approach the efficiency of a train, as far as wind
resistance goes. If wind
resistance is the major player, here, then the steel rails aren't needed. Just
do the drafting.
Then, there's the cost consideration: how much would it cost to put in high
quality rails on the
long stretches of the Interstates ? A lot.
Peri
<< Annoyed by leaf blowers ? https://quietcleanseattle.org >>
------ Original Message ------
From: "Peter VanDerWal via EV" <ev@lists.evdl.org>
To: "Electric Vehicle Discussion List" <ev@lists.evdl.org>
Cc: e...@vanderwal.us
Sent: 03-Dec-20 9:07:07 AM
Subject: Re: [EVDL] 'All's not well with UK public charging' / Autonomy
If that's the case, then they aught to embed steel rails in the lane. The
truck can get to/from the
lane on rubber tires and then switch to steel wheels on steel rails. Much
better efficieny, reduce
wear on tires (saves money) and less micro-partical pollution.
As an added bonus the rails could be electrified to power the trucks so they
don't need to haul
around tons of batteries. Power could be derived (at least part of the time)
by using solar roofs
for those lanes.
This, of course, would make too much sense to ever be implemented.
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