Can't remember which author OR book, now, but there was a SciFi that
depicted a world where all transportable energy sources were by giant
springs -- except with some futuristic molecular science in them that
allowed a single spring that could reasonably fit in a small vehicle
power same for hundreds of miles.
I can't remember the story exactly, but it was about a rebellion on a
colony planet. The colonizing society was high-tech, but the colony was
forced to be low-tech; thus the spring-wound transportation.
Long ago, I think it was in England, they had something I think it was
called a Penny Farthing, something like that, I think.It was a wind up
spring motor for bicycles. Long before that, a guy in Italy invented
some sort of a wind up spring 'car', or at least he sketched it on
I will remind all that businesses usually try to avoid
the use of compressed air for things like tools when
It's a very expensive & wasteful mode of
"Over 15% of total motor energy in the industrial sector goes to producing
compressed air, yet compressed air systems are inherently inefficient, producing
only one unit of useful work for every 5 units of energy input."
"For a compressed air system in constant operation in a facility whose
electric energy cost is 5 cents/kWh, a 1/16 diameter leak costs about $500 per
year, a 1/8 diameter leak about $2,000 per year, and a 1/4 diameter leak about
$8,000 per year."
Well, if this is true, then the air car is doomed. :(
There are also compression losses itself, from the heat produced (pv = nRT),
but I was under the impression those would be relatively minor, altho I
haven't done the calcs. Theoretically, in an insulated tank, this really
wouldn't be a loss, but insulation is indeed a pita.
It could be that the rotor losses are indeed substantial.
For example, the energy retrieved from wind energy is only about 50%,
because of the "dead" air at the blades, etc.
I sort of assumed that in an engine, they would have greatly reduced these
losses, but mebbe not.
In the original features of the french guy designing this air car, they
claimed that it cost like $2 for an air charge that was good for a whole
bunch of miles, amounting to a *fraction* of the gasoline cost.
And yeah, it seems reasonable that an air tool WOULD be substantially less
efficient than an electric tool, as there are losses in BOTH directions:
compressing the air, AND delivering the air through the tool rotor, whereas
the electricity used to compress that air can just drive the tool directly,
at near-100% efficiency.
Heh, mebbe batteries ARE the way to go.... but the problem there is the
PRICE.... holy shit.....
No free lunch, eh??
Air Car = Cold Fusion??? No real excuse for all these ambiguities....
Mebbe a big-assed spring is an answer......
But be careful with that, you'll poke yer eye out.... (Xmas Story.....)
Pt 2: Just how big ARE these heat losses?
pV = nRT.... mebbe p1v1/T1 = p2v2/T2, solve for T2, then E = mcdelta T as
the energy lost??
Heh, but what's V1?????
Could just measure T2..... how hot is hot??
But since m and c for any gas are pretty small, the total energy is pretty
small. I mean, we're talking a delta T of, what, mebbe 100 deg? 200 deg?
Still a very small E.
I personally think the blade losses, as in a windmill, would swamp the heat
losses due to compression.
I looked at running some numbers but quickly got
in over my head so I fell back to MIL-STD-1522A,
page 10, which gives a chart of potential energy
The classic example is 2 tanks, equal volumes
connected with a valve. Pressurize one to n psia,
the other to zero psia, calculate total energy,
open valve, recalculate total energy. As I
understood your original statement, the total
potential energy should stay the same.
From the chart in MIL-STD-1522A you can work out
that if n0, you lose 30% of your energy and
with n00 you lose 10%. Not as huge as I
expected, but not negligible either.
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