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Towing a Tesla at 70 MPH replenishes battery at fast charger rates

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Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#331

Post by worldsayshi »

recursive wrote: post #171
worldsayshi wrote: post #124

Couldn't we use smart kites that would fly around hooking up to your car as sails whenever there's a lot of wind in an area with open skies? Get towed, charge a bit and/or save battery. The car automatically sends some fee payment as a thanks. Requires a lot of smart infrastructure that we don't have but it seems like one of those things that should be doable once we've figured out autonomous driving...

How often will someone be driving slower than the wind? Almost never.

You can sail faster than the wind when you push against a medium though.

Veritasium has a very relevant interesting episode on this: https://youtu.be/jyQwgBAaBag

Although I agree it would be challenging to get any significant speed from it.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#332

Post by rini17 »

jvanderbot wrote: post #287
bigiain wrote: post #218

Earlier quoted context omitted.

A 20% grade is probably unachievably steep for ordinary railways. Even a 5% grade is considered remarkable. Wikipedia says ( https://en.wikipedia.org/wiki/Saluda_Grade ): Saluda Grade is the steepest standard-gauge mainline railway grade in the United States.[1] Owned by the Norfolk Southern Railway as part of its W Line, Saluda Grade in Polk County, North Carolina, gains 606 feet (185 m) in elevation in less than th…

per train . Long track: more trains, right? Great points though!

Then you also need hefty wires and adjacent infrastructure on whole track to collect all this electricity.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#333

Post by rand49an »

cartoonworld wrote: post #252
xattt wrote: post #244

Earlier quoted context omitted.

I had a VW Golf with a DSG (DQ250) which I regularly engine braked on hills. However, I noticed that the instantaneous fuel economy meter would show some consumption on downshifting versus no consumption on coasting in drive. It turns out that the logic will try to rev match to be in a lower gear before cutting off the fuel again. Rev matching wasn't perfect either, as going down more than one gear would cause the en…

Ouch, lots of the VW fans I've known were die hard due in part to the ergonomics and feel of the manual transmission. Something about a cable I think. Too bad VW mechatronics doesn't read the throttle position for a clue here. It all just seems so obvious.

VW transmissions haven't used a cable in many years, 30 plus.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#334

Post by underwater »

tomjakubowski wrote: post #74
underwater wrote: post #67

Earlier quoted context omitted.

Windy is a perfectly valid descriptive word for a twisting road.

the confusion in this thread is that windy, as written, could mean there's lots of wind (said "win-dee") or lots of bends (or "winds", said "whine-dee"). "winding" is less ambiguous

Obviously. But `croon` seemed to think that windy was was incorrectly, not just ambiguously: "I think OP meant winding and not windy"

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#335

Post by elihu »

kllrnohj wrote: post #167
elihu wrote: post #120

This seems like an interesting solution to the "what to do if my battery runs out in the middle of nowhere" problem. Normally, you'd either have to have to call a tow truck or have someone with a generator come along and recharge. However, towing for awhile (probably at much less than 70 mph for safety reasons) to recharge the battery enough to get to the next town is something that could presumably be done by just a…

Only if any of those passing cars are gas-powered. If the passing cars are themselves also EVs, then there's both more obvious forms of energy transfer, but also you'll be taking that much range (and more) from the EV doing the towing.

Transferring energy from one car to the other isn't quite that straightforward, even though it's something that sounds like it ought to be easy. (The simplest thing would be jumper cables, but there's not usually any easily-accessible high voltage terminals, and the batteries might be different voltages anyways. And you'd want to limit curren, and so on....) Maybe if the new Ford F150's 220-volt outlet becomes a common feature, then charging from one car to anther will be easier (though very slow).

I think the main towing advantage a typical ICE car would have over an EV with extra battery capacity is the ability to shift into 1st or 2nd gear. It's not really an intrinsic property of EVs that they can't have transmissions, but so far the major manufacturers have decided it's not worth it. (The Taycan is a notable exception.)

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#336

Post by Gravityloss »

FridayoLeary wrote: post #78
ols wrote: post #56

The most spectacular example of regenerative braking are trains that are used in Scandinavia, heavily loaded with iron ore that is transported to the coast: "In Scandinavia the Kiruna to Narvik electrified railway carries iron ore on the steeply-graded route from the mines in Kiruna, in the north of Sweden, down to the port of Narvik in Norway to this day. The rail cars are full of thousands of tons of iron ore on th…

The heavy iron ore is essentially a large battery storing gravitational energy. In a way it's just another natural energy source. Maybe in the future clean power can be generated from pulling down mountains.

Scifi novel idea: A habited planet without a sun (these actually exist) with heavy elements and high gravity. The surface unevenness is the best source of energy. After millions of years of extracting energy from flattening, the planet becomes a perfect ball and all life ceases as there is no energy to be found anywhere.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#337

Post by jeofken »

rightbyte wrote: post #162
jeofken wrote: post #84

Earlier quoted context omitted.

Volvo did a trial of this. Not sure how it ended up. https://www.volvogroup.com/en/news-and-media/news/2018/sep/v...

There are nasty leak currents when the ground is wet. I wonder of they managed to fix that. Air wires will probably be the way to go, but those will unfortunately be to high for cars.

They also did a trial of a highway with power lines above, like a city tram, but I don’t know the search query to find anything about it. Was ~5 years ago

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#338

Post by jgjot-singh »

bodyfour wrote: post #146
mdeeks wrote: post #113

Earlier quoted context omitted.

Apparently there is already the concept of rail train batteries: https://www.vox.com/2016/4/28/11524958/energy-storage-rail You run the trains up the hill when energy is cheap or, for example, when the sun is out and solar works. Then when you need it, you run the trains down hill to generate electricity. Similar to pumped hydro where they do the same by pumping water up hill and then draining it downhill later. Supe…

It's interesting as a thought, but I don't think it's likely to be large-scale practical. Suppose you wanted to run a normal electric train up a mountain. It would certainly take a decent amount of power but not so much that it would be a big challenge for a city-scale power grid. So far you're not yet talking the scale of power where storing it would really be interesting to a grid. One option to store more power wo…

Perhaps the trains could partly be passenger trains, costing amusemant park rates.

Then collected money could eventually pay off the cost of construction, and eventually maybe even offset the maintenance cost.

If nothing else, it would certainly boast the advantage of being more fun than water storage.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#339

Post by lucian1900 »

Retric wrote: post #20
croon wrote: post #8

Earlier quoted context omitted.

I assume this is tongue-in-cheek, but just pulling up close to you and springing out a charging cable arm would be more efficient.

And even better just embed some wires in the road and charge everyone at highway speeds. Either ground-level power supply through conductive rails or inductive coils both work with different tradeoffs. https://en.wikipedia.org/wiki/Electric_road

Trolleybuses are a much simpler design with better efficiency. And trains are even more efficient than that.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#340

Post by fho »

dandelany wrote: post #315
fy20 wrote: post #258

Earlier quoted context omitted.

The idea of pumped storage is pretty simple, but compared to lithium batteries the energy density is ridiculously small. If you already have an area that can be used for it (abandoned mine or reservoir) then it's pretty simply technology to build, but otherwise it's probably not worth it. As an example of how low density it is, imagine having a 1000l IBC tank, filled with water, on your roof at a height of 10m. That…

Density isn’t everything. It’s likely a lot cheaper and less environmentally destructive to dig a big hole in the ground than to manufacture a lithium battery.

Stripmining was not exactly "environmentally beneficial" ... and that is literally digging a big hole.
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