[ExI] Small scale solar payback time (was Re: Planetary defense)

[Eugen Leitl]

On Tue, May 17, 2011 at 06:50:52AM -0700, Keith Henson wrote:

> If you had a polymer PV that had an energy payback time of a couple of
> months and lasted 2 years, that would be possible to grow energy on

Great if you roll it out in the desert, and weigh down with stones.
Total deployment time: <30 min. And you can always drive down
to Walmart and get another roll of polycells-last-all-summer-long.

Not so great if your home's outer skin is made from it. Here
you'd want to go for 40+ years. (Yes, houses and people will
be still around in 40+ years).

> the energy harvested, i.e., short doubling time.  PV that takes years
> to pay back the energy used to make it has a slow doubling time.

When PV panes are autopoietic, yes. As long as you put them up
by people, not so great.

Apropos solar: http://postbiota.org/pipermail/tt/2011-May/009071.html
 
> I would rather have a short EPBT.  YMMV.

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