[PSUBS-MAILIST] Fuel cells

[CWall@swri.edu]

Herve, I work for a group that designs advanced vehicle systems, and I'm their
fuel cell guy.

It's not quite as rosy as the press releases would lead you to believe.  The
biggest problem is that of the fuel itself- most fuel cells require hydrogen,
and hydrogen is bulky.  Reforming other fuels to get that hydrogen involves a
lot of additional equipment.

Other fuel cell chemistries are available, and manned submersibles have been
built using them....but I really don't think you want to go after
hydrazine/nitrogen tetroxide systems.

Having said that, there are some opportunities to use small fuel cells as APUs
for battery charging, but these are Proton Exchange Membrane Fuel Cells
(PEMFCs) that require hydrogen- and they aren't cheap.   Nor are they readily
available, despite what you see on the websites.

The one real hope is for small SOFCs (Solid Oxide Fuel Cells) that can be run
with hydrocarbon fuels following a simplified reforming process.  They are
unfortunately high temperature cells- in the 700-900C range, and they aren't
available yet either- but they may be soon, and in the 3-10 Kw range that would
 be useful.   The problem is, you can't start and stop them easily- it takes a
day or two, and basically you'd never want to shut them down.    And like all
fuel cells they require air or oxygen or at least some oxidizer. They'd make a
good trickle charging device for shoreside power, though.

Craig Wall