fuel cells?

It seems that every day now some electronics giant is announcing their micro
fuel cell.
See: http://www.goodcleantech.com/2008/05...ybrid_fuel.php

What I want to know is whether these things have a place in gliders. The
first concern that pops into my head is that they must depend on atmospheric
oxygen which might not be enough at high alititudes. Anybody know?

On Mon, 05 May 2008 12:57:36 -0600, Bill Daniels wrote:

It seems that every day now some electronics giant is announcing their
micro fuel cell.
See:
http://www.goodcleantech.com/2008/05...ybrid_fuel.php

What I want to know is whether these things have a place in gliders.
The first concern that pops into my head is that they must depend on
atmospheric oxygen which might not be enough at high alititudes.
Anybody know?

I suppose you could always use an (electrically driven) supercharger if
that is a problem. However, as Aerovironment were planning to use a fuel
cell in their electric flying wing, which operates at 80,000 ft, I suppose
the problem, if it is one, is solvable.

The more relevant questions concern the energy density of a fuel cell plus
supply tank and its energy efficiency. I've not seen anything about energy
density, but its efficiency over a charge/discharge cycle is far below
Li-poly batteries - something like 66% vs 85%, which makes it less
attractive for a solar powered 'eternal airplane' than Li-poly cells.

If you're talking about using it to fly a ground-charged SLMG, then the
energy density would be the critical factor. You probably wouldn't want to
use a hydrogen fuel cell because the energy density of a tank of hydrogen
is rather low.


--
martin@ | Martin Gregorie
gregorie. |
org | Zappa fan & glider pilot