From: ems@michael.apple.com (E. Michael Smith)
Subject: Re: Renewable Energy - solar
Organization: Apple Computer Inc, Cupertino, CA
Date: Sat, 21 Nov 1992 17:25:40 GMT

In article <1992Nov20.060352.20615@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>In article <Nov18.182720.65718@yuma.ACNS.ColoState.EDU> kk881595@longs.LANCE.ColoState.Edu writes:
>>In article <1992Nov14.185409.17561@ke4zv.uucp>, gary@ke4zv.uucp (Gary Coffman) writes:
>>|> Actually, all the approaches listed, with the exception of geothermal,
>>|> *are* solar energy. And *all* have better efficiency than *direct* solar.
>>|> However, the *most* efficient collectors of solar energy remain *plants*.
>>|> Burning plants, freshly dead, or concentrated under tons of rocks for
>>|> eons, is still the most efficient use of solar energy. And there is very
>>|> little capital cost involved with setting up the "plants."  :-)
     ^^^^^^^^^^^^^^
I suppose in the clasical economic sense of land, labor, & capital...
but if you consider land cost as a capital expenditure ... farms
are not cheap...
 
>>If one added the
>>additional processes involved in converting the plant to
>>fossil fuel then the "efficiency" would be even worse.
>
>Ah, but unlike photovoltaic cells, or solar thermal collectors,
>it costs us nothing, or nearly nothing to deploy organic solar
>collectors. 

Whoa there!!  It is clear to me that you have never lived in farm country!
Running a farm is not 'nearly nothing' in costs!  It is running about
$10,000/acre for decent land out here...and don't talk to me about
what it would take to buy new water rights ...

>Converting that energy to readily usable combustibles
>also costs us nothing. 

Again, a quibble:  Every seen a Rice Dryer?  Corn Dryer?  Right now
there is a major jump in propane demand 'cause they had a bumper
corn crop in the MidWest.  That standing crop of wet fuel plants
will need to be collected, chopped/formed/whatever, and DRIED.

Now, you could let it dry in the fields, if you live somewhere like
California where the rain stops in summer.  But that standing crop
drying in the field is preventing you from planting your second crop
of the season ...  If you dry it by stacking it, you have labor costs
to transport and handle.

OK, so we go for a wet ferment instead of drying it ... now you have
the capital cost of the fermenter and the labor costs and ...

My point?  'costs us nothing' is a brazen red flag.  On a farm,
everything costs you something ... 

>Our only cost is that of recovery, and that's
>only a fraction of the cost of photovoltaics.
>
>Whether the *thermodynamic* efficiency of photovoltaics is higher
>or not, I can't say, but the *economic* efficiency of plants as
>energy collectors is a clear winner.

While I agree with the general conclusion that plants can be 
an effective solar energy collector, the zero cost items on
your list are in need of a bit of review ;-)

The biggest advantages of solar plant farms are the production of
chemical feedstock alternatives and the innate energy storage system.

-- 

E. Michael Smith  ems@apple.COM

'Whatever you can do, or dream you can, begin it.  Boldness has
 genius, power and magic in it.'  -  Goethe

I am not responsible nor is anyone else.  Everything is disclaimed.