On Mon, 23 Jun 2008 16:35:03 GMT, wrote in
:

Larry Dighera wrote:
On Mon, 23 Jun 2008 15:15:03 GMT, wrote in
:

Except they can't as battery technology is an order of magnitude short
on energy density to be able to do it.

I've always thought that the energy stored in metallic aluminum might
be harnessed for motive power. If you look at it on the energy
density chart http://en.wikipedia.org/wiki/Energy_density, it would
appear to be a reasonable energy source.

Storage type Energy density Energy density
by mass (MJ/kg) by volume (MJ/L)
----------------------------------------------------------
Gasoline[7] 46.9 34.6
Aluminum (burned in air) 31.0 83.8
Hydrazine (toxic) 19.5 19.3
combusted to N2+H2O

So while aluminum isn't as rich an energy source pound-for-pound as
gasoline, it is significantly better than rocket fuel.

Well yeah, except it takes huge amounts of energy to make metallic
aluminum from ore in the first place

Right. http://electrochem.cwru.edu/ed/encyc...a01-al-prod.ht
It takes about 225 KWH to produce 50 lbs of metallic aluminum.

All the energy that went into making the alumna into metallic aluminum
is just waiting to power an IC engine. Grind the Al into a fine dust
and blow it into the cylinders. :-)

and burning aluminum is not something you really want to be around.

Can you tell me more about that?