Skywise wrote:
Larry Dighera wrote in
:

She also said the hydrogen would be compressed to ten bar,
which would raise its energy density comparable to that of
gasoline.

I'm not so sure about that.

An article I found many many years ago, published in 2002,
discusses such things. If the information in the article is
correct, it is extremely difficult to beat gasoline for
energy density.

It lists gasoline as having an energy density of 9000Wh/l
(watt-hours per liter).

150 bar H2 is only 405 Wh/l.

Liquid H2 is 2600 Wh/l.

Lithium batteries are listed as 250 Wh/l, but mind you
this was published 12 years ago. Battery technology has
made large leaps since then. Even if they've only
doubled in energy density since then, that would still
beat 150 bar H2.

http://www.tinaja.com/glib/energfun.pdf

Brian

For aviation use, the energy density by weight and volume are both important.

Try he

http://en.wikipedia.org/wiki/Energy_density

Note none of these account for any required container, which in some
cases can be very significant.



--
Jim Pennino