[Tfug] OT:Battery Powered Transportation

[Bexley Hall]

Hi Charles,

> Sorry Don, for some reason you were always Bexley to me.

<grin>  I've been called worse!  ;-)

> Anyway, you say,
> 
> > So, instead of driving your land yacht to the grocery store
> > half a mile away, you possibly walk (gasp!) instead.  Or,
> > use the eq
> 
> According to the numbers, apparently people are incapable
> of fathoming the enormity of the energy demand in the
> transportation sector. ie. quadrillions, 10^15 BTU, etc.

Of course!  I'm an engineer and, once you get past a handful
of zeroes, all numbers become meaningless!  People also fail
to see how *population* (numbers has such a dramatic effect
on things.  E.g., you drive an extra mile a week and it
seems like that's a drop in the ocean -- until you "look down
the shoreline" and realize there are millions of people that
are making that same 1 mile trivialization.

Numbers are hard for people to wrap their minds around.
A favorite (trivial) mind game to illustrate this:

Make a steel strap that fits the Earth snugly at the equator
(assume oceans are solid, mountains flat).  That strap will be
~25,000 miles long -- roughly 125,000,000 *feet* (since most
folks can't do that math in their heads "on the spot").
Now, cut that strap and insert a 36 inch long (3 feet) piece.
Assuming the enlarged strap "floats" equidistant from the
Earth in all places (i.e., "concentric"), how large a gap
will there be between the strap and the surface of the
Earth?  (remember, the strap previously was a *snug* fit)

This is a trivial problem to solve yet the answer -- about
6 inches -- stuns people!  It seems "too large" to most
folks!  Yet, it is exactly what it *should* be AND when
considered w.r.t. the dimensions of the Earth, it does seem
as *tiny* as intuition suggests it should be!  But, people
dont see it that way.

Another similar example I use to illustrate weight gain/loss:

Average person gains about 10 pounds each decade (up to a point;
then it reverses for some, etc.).  That's roughly a pound per
year.  A pound is roughly 3000 "calories" so figure this
means the person's metabolism is burning ~10 calories LESS
than that person is consuming DAILY.  I think a life saver
is something like 14 calories (?).  I.e., if you eat one life 
saver less each day, you "break even".

> Even if that yacht were reduced by a factor of 1000,
> essentially weighing about 3 pounds (include some
> uncertainty factor less than 10 here), an additional 5000
> regular sized nuclear plants, or the equivalent capacity in
> windmills, would have to be produced to power its transport
> across the same mileage as the aggregate US population, ie.
> meeting the mobility needs of 300million+ individuals, each
> weighing and average of 100lbs., say.
> 
> I don't buy the whole battery powered vehicle arguments, I
> suppose if you want to make a small vehicle, make a small
> vehicle, but the energy is going to come from somewhere, and
> it's going to be a similarly incomprehensible amount.

I don't think the electric vehicle argument makes sense, either.
But, I *do* think you need something "noticeably different"
in transportation to get people to change their expectations
of energy consumption for transportation.  You can't just make
small gas powered vehicles; people don't buy them (in the long
run).  You need to change the equation so that inefficient
transportation mechanisms simply "don't work".  E.g., imagine
hauling an SUV around town and only being able to drive 80
miles before needing to recharge it (since doubling the size
of its battery is not as easy as doubling the size of its
gas tank!).  Then, the inconvenience of having to "fill up"
3 times a week becomes enough of an annoyance that maybe
the owner considers something less burdensome.

I *do* think there is a market for a "metro" sized electric
vehicle.  Especially in reasonably urban areas.  But, the
economics of batteries just don't make much sense.  Imagine
having to replace/rebuild your engine every 3 years or so...

> I'm pro-hydrogen.  The shuttle doesn't propel itself
> into orbit using a battery for a reason. I think the whole
> battery vehicle thing is absolutely ridiculous and just a
> power grab by the electricity industry which I would imagine
> is hundreds of thousands of times larger than the hyrogen
> industry. Not that it's a conspiricy however, just wishful
> thinking, IMHO.

I think that just shifts the problem without really changing the
mindset.  Like when diesel came into its own as a mainstream
fuel (70's).  Those folks who switched to diesel vehicles
early on saw some savings.  But, now diesel is just the same
as gasoline.  Energy density is similar so people don't
change their driving habits.

H2 may have an impact *if* the practical limits on tank size
end up significantly reducing overall driving range.  But, I
suspect The Industry will address that by making swappable tanks
so fillups aren't as inconvenient/time consuming.

> I suppose car could run on anything if the roads were
> frictionless and inside a vacuum tube, perhaps no actual
> work would be necessary (integrating a round trip). 
> :)

Railroads.  Steel on steel.  It amazes me how much the
trains can move on a given unit of energy!

<shrug>  I can't change the world.  But, I can try to
influence "this much" (arms outstretched).  That's what
I set as a realistic goal for *myself*.

YMMV <wink>

--don