Yes, grim, in a way, we should recover it where we can, but the scenario you describe gets only that single last deceleration, over a few hundred meters. Your car (truck, whatever) had to output vastly more energy overall to get you there: Initial acceleration, maintaining speed against the resistance of the air, slow and speed up several times during the trip. Now, at the very end, one recovers a poofteenth assuming one either enters the extractor at normal speed or it is a downhill run to the filling station. You cannot recover more than it takes to get you back on to the freeway at speed, less inevitable losses.
(Yes the slowing truck might well launch your car, so it might be worth building)

The principal attraction of pneumatics is the same as for batteries etc. To make it work, one has to trim the vehicle down to fit the power source. We can already do that. Had a 800cc Suzuki with a top speed of eighty that would now be thirty years old. It is light enough to convert to battery, to pneumatic, or to just run economically on fuel. If all commodores, big fords, toorak tractors etc were so trimmed, there would be almost no need for this thread.

rstuart,
The misunderstanding is not entirely mine. You did not say the Lexus gave a net consumption of 13kWh over a typical journey, did you? You extrapolated from a constant speed, as indicated at 100km. I used your figure. I just bet the power indicator exceeds 25kW many times during a real journey, particularly when starting and accelerating. If you were actually quoting average consumption on typical journey say so.

The optimality I referred to is compared to the aged and heavy cars actually on our roads in great numbers. Steady driving at 100 is not what many do, even in a lexus. If regenerative braking is so good, then style is not the issue, speed is.

The EV gives better performance, but it was not your example, was it? The Tesla too, but it is not a lexus and not cheap. The consumption is still the same order of magnitude. Many if not most commute for more than half an hour. It still uses far too much energy to have transport of the standard we are used to on a home renewable source.

I don't doubt that such will get better and better. I want them to.

What I am pleased about is that the new electrics are better than I thought.

Cheers

Rusty

Thanks Everyone for your input.

I think you're right about hydrogen-powered cars.
Ah well, wishful thinking on my part as usual,
I suppose. I watch these TV programs, get all
excited about what I think is a new innovation -
and then someone comes along and sets me straight.
(Besides I'm trying to impress examinator).

Back to the drawing board.

I'll stick with scientific American mags. from now on -
rather than National Geographic. :)

I'm obviously out of my league here.
So I think I'll go - bake a chocoalte cake
instead...

Yes Foxy it's really a great dilemma. People need to look past the length of their noses to see there's really no solution at the moment without some revolutionary scientific discovery. When looking at alternatives like hydrogen, compressed air and other such waky ideas, one need to ask a very simple question, where did the energy come from that creates these alternatives!

Rawmustard

"where did the energy come from that creates these alternatives!"

An excellent question and definitely something to be mindful of, however we will never make a move at all if we allow ourselves to be tangled by too many trees. We do need to focus on the big picture which is to attain a sustainable economy. There not being any magic bullets, all ideas deserve consideration. Where I get impatient, is that we do have some alternatives we could be implementing right now. Significant investment into public transport, being just one example.

And hydrogen should not be dismissed completely given that it is the most common element in the universe. However, ATM the electric car is holding much promise and I am confident we will find a way to create small high powered batteries. We have some great minds working on these issues. We are only limited (no I am not going to say 'imaginations') we are limited by a powerful minority who don't want or fear change.

Hydrogen may yet have a role for some high-performance applications.

What rstuart has been trying to approach (repeatedly with me, unfortunately) is that with regenerative braking the electrics are way ahead of the competition. A motor that worked just as excellently as a dynamo, and batteries with minimal cycling losses starts to approach the energetic simplicity of a ballistic path. Suddenly the only losses are resistive (engine friction, battery and electrical resistance, and the resistance of the air). These are all reducible to some extent, including by going slower as resistance is proportional to the square(or such) of speed.

We still need to feed these less hungry beasts. If all cars were suddenly electric, the grid would have to deliver considerably more power. I had thought several times more, rstuart has convinced me that maybe as little as twice (though I think more is likely) - so long as everybody drives some limited distance such as 25km or less.

That is within the realm of possibility. The fuel the cars would have burnt will burn better in large fixed generators, the cars being considerably more efficient will use less overall. This might serve as a stop gap till enough alternatives could be added to double the supply to the grid.

And that could be done with no new technology.

where next?