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

[Emlyn]

On 17 May 2011 23:20, Keith Henson <hkeithhenson at gmail.com> wrote:
> On Tue, May 17, 2011 at 12:01 AM, Eugen Leitl <eugen at leitl.org> wrote:
>> On Mon, May 16, 2011 at 11:19:37PM -0600, Kelly Anderson wrote:
>>
>>> Ok Keith, I see where I went off the tracks now. You're talking about
>>> ENERGY payback time, and at the time I was thinking about monetary
>>
>> EROEI is always preferable to EPBT. You can have short EPBT at
>> negligible EROEI, e.g. if you use polymer PV which burns out
>> in a couple years.
>
> 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
> 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.
>
> I would rather have a short EPBT.  YMMV.
>
> Keith

If the tech is improving at a good clip, then the idea of short
payback time, disposable cells (hopefully recyclable) might be highly
preferable to long lasting tech; you don't want those cells up on your
house for 40 years if 5 years after you install them, they are an
order of magnitude worse than the new cheap stuff in the shop. Sort of
like, who is currently using a 40 year old computer, or even a 10 year
old one?


>
>>> payback time, which is completely different. My apologies for the
>>> misunderstanding.
>>
>> --
>> Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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