On Apr 30, 10:51=A0am, mimus <tinmimu...@[EMAIL PROTECTED]
> wrote:
> On Tue, 29 Apr 2008 06:31:07 -0700, a...@[EMAIL PROTECTED]
wrote:
> >http://www.cnn.com/2007/TECH/03/09/cars.100mpg.popsci/index.html
>
> All three of those techniques mentioned were interesting, and ought to
be
> combined in a four-seater.
>
I especially liked this portion:
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The EPA has built a modified hybrid that uses a hydraulic system, not
a battery, to store braking energy. When you press the brakes, the
wheels drive a pump that compresses nitrogen gas, which is inexpensive
and inert. When you accelerate again, that compressed gas runs the
pump in reverse to help power the vehicle.
The hydraulic-hybrid system, scheduled to begin testing in two UPS
trucks this month, with another to follow next year, promises to
return at least 70 percent of the braking energy back to the wheels,
which would lead to a 60 to 70 percent jump in fuel economy and a 40
percent reduction in emissions.
Perhaps that's why Charles Gray, the director of the Advanced
Technology Division and one of the developers of the hydraulic hybrid,
can't contain his excitement about its potential.
"This is going to be the biggest revolution in automotive history," he
declares. "Bigger than the assembly line."
That's yet to be seen, of course, but the hydraulic hybrid is also
smaller and cheaper than conventional hybrids.
"I can hold a 500-horsepower hydraulic pump motor in my hand, and I'm
not a big guy," Gray says. Because the technology would eliminate the
need for a transmission -- the engine merely pressurizes the hydraulic
system, while the hydraulic motors power the wheels -- and several
other parts, it could be installed in a small car for almost no
additional cost.
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It sounds credible, and given that the applicability of this to
existing vehicle designs is very wide, very exciting.
> But it's hard to believe a gallon of gas, however well converted to
energy=
> (other than by nuclear reactions, and maybe not even then), could
> transport two people 300 miles.
>
> Maybe at a mile an hour. =A0Maybe.
>
In the case above, as they point out, most of the time there's a lot
of waste heat and wasted momentum.
> Also, all of this is, again, just so many band-aids for, and so
> much diversion from, and so much continued avoidance of facing up to the
> need to do something about, our gross global overpopulation.
>
In the long run, this is important too. A context must be created in
which we provide better for those living in poverty, and for greater
empowerment of women and girls precisely so that both the incentive
and the opportunity to have large families declines.
That will take a while to turn around though, and there's probably no
avoiding 9 billion people. But with good programs, by 2100, world
population might well taper to something like 7-8 billion and mid 22nd
Century at about the 6.5 billion we have now.
Of course, if everyone wants to consume at the rate we are in the
first world, then a 'sustainable' population is probably closer to
about 2-3 billion. Fortunately, large tranches of this consumption are
simply wasteful, and once that is taken out of the mix and we make
more rational use of the resources available, the society of that day
ought to be able to sustain 5 billion pretty comfortably.
Fran
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