[ExI] Direct solar electrolysis - decentralised fuel infrastructure, is it viable?

Emlyn emlynoregan at gmail.com
Tue Oct 14 03:28:35 UTC 2008


Keith's evangelism of solar power satellites is very interesting, but
the extreme centralisation of the power production has to make you
nervous; at best, it's business as usual big capital monopoly on
power. I think we should probably do it, actually, but the barriers
seem so large.

On a related note, I recently watched the talk "Energy Literacy" by
Saul Griffith (http://etech.blip.tv/file/1018152/), and was of course
daunted by the scale of terrestrial plant we'd need to construct (and
the amount of land it would require) to do anything serious about
greening world energy production.

It got me to thinking, is there a way to decentralise this? Could we
think of a way that, instead of requiring mega engineering, mobilised
thousands (millions?) of "mom and pop" operations to do the work?

Also, I'm based in South Australia, one of the great early losers of
the climate change debacle. The feeder river into the state (there is
only one of any consequence), the River Murray, is just about dead,
and it's just not really raining any more. So, the northern part of
the state which is unusable for agriculture (think red desert) is
marching south at speed, the ability to provide enough water for the
state capital Adelaide is in doubt, and farmers are no longer allowed
to irrigate in many places, ie: are sooo screwed.

So what we have here is:
- Sunshine (not much ozone layer to worry about way down south here, either)
- Land (unusable)

So I think solar power is probably a go.

What we should really do here is create some godawfully huge solar
power farms, cover masses of that desert, produce massive amounts of
power, use it to run lots of desalination plants, and away we go. The
city isn't landlocked, after all. If we threw money at it on a large
enough scale, we could set up serious world leading research
facilities, boost the unis, and eventually maybe have something of
interest to export.  But I digress.

I'm thinking, what can small amounts of capital do here? You could set
up a little solar farm, presumably, for thousands rather than
millions, on cheap land (you can buy ghost towns for less than a
modest house in the city), but then what? I get the impression it is
expensive to be a traditional power plant; you can just pump the
output of your small solar farm into the grid and expect that to be ok
or make you money.

Or you could make hydrogen, I'm thinking. Pump the solar generated
electricity into hydrogen electrolysis equipment, voila lots of
hydrogen. You need water, problematic potentially, but do you need
much? Anyway, suddenly you are making fuel. That fuel can now be
trucked around, or you could sell it directly if you were next to a
decent road, just put a fuel station ("gas" station) on the front of
your farm.

And that turns out already to be being done in California, apparently.
I can't find a link to anything direct about that, but apparently
there is such a station there. Can someone link something more
specific?

So... could you turn this into something commercially viable for a mom
& pop operation, such that they lay down their dollars, a solar farm +
hydrolysis equipment + storage facilities + commercial gas station is
constructed, and they then operate this, selling their gas? I don't
have numbers, and am struggling to put any together, just not my
expertise I'm afraid. With 25 year lifespan on the kinds of solar
cells you'd use, you don't have the problem of replacing cells all the
time, but it could possibly be scuttled by a poor hydrolysis
efficiency compared to centralised large facilities. Also it assumes
people actually start wanting hydrogen in the future; right now no one
wants it, certainly not at the price of electrolysis (see here:
http://www.iags.org/n032805t2.htm).

I also can't get a feel for how much land you'd need to produce a via
amount of hydrogen. I have access to a nanosolar solar cell sample
here, with peak output of about 0.33 watts for a piece about 0.01m^2 ,
so thats 33 watts for 1m^2, or 1kW for 30m^2. It's not a high
efficiency type of cell (20% I think), but flexible printed stuff,
cheap apparently, no numbers available though sorry.

-- 
Emlyn

http://emlynoregan.com - my home
http://point7.wordpress.com - downshifting and ranting
http://speakingoffreedom.blogspot.com - video link feed of great talks
on eCulture



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