[ExI] Novel technique for cheap and abundant hydrogen

[Eugen Leitl]

On Tue, Nov 13, 2007 at 09:58:59PM +1100, Stathis Papaioannou wrote:

> Why not store the electricity in batteries 

Hydrogen/air fuel cells *are* batteries, which happen
to have gaseous electrodes. DMFCs have liquid electrodes.
LiIon has solid electrodes. The electrolyte can also be
anything from liquid to solid.

> instead of using it to make explosive gases?

Hydrogen in a storage tank isn't explosive. You'd
need to mix it with an oxidiser. Natural gas is very
explosive, too, and not nearly as quick to dissipate
as hydrogen, but is nevertheless used widely. 
It's considerably safer than e.g. a lithium battery which
suffers an internal short-circuit, and produces a nice
runaway metal fire. Also, batteries have very limited
charge/discharge cycles, after which they must be recycled
in their entirety. Both lead-acid and lithium batteries
are problematic, for toxicity and scarcity reasons.

Water is cheap and plentiful, while lithium is not.
Pressure storage tanks are cheap, too. You can also use
a gasometer, of course, since the energy density is
quite considerable.  Water electrolysers are fundamentally 
very cheap, and can generate pressure directly,
without using a compressor. Fuel cells can be made very 
cheap fundamentally, with a bit more R&D. Same applies
for improving electrolysis efficiency.

-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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