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

[Damien Sullivan]

On Sat, May 21, 2011 at 01:59:09PM -0700, Damien Sullivan 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
> 
> If you had that you'd have EROEI of 48 months / 2 months = 24, pretty
> good.

I'm apparently too sleep-deprived.  That'd be 24 months / 2 months = 12,
of course.

Which raises the question: is it better to have fast growth but high
maintenance costs, or slower growth but cheaper equilibrium?  If you
have 2 month payback, EROEI 12, vs. 2 year payback, EROEI 24 (48 year
lifetime), which is better?  The first lets you transform faster, but
has twice the 'maintenance and replenishment tax', not counting labor
costs.

(Similar to bus rapid transit vs. urban rail; you can deploy the buses
faster, but the trains take less maintenance and energy over their
lifetime.)

-xx- Damien X-)