🚀 go-pugleaf

In article <30E0AFD5.41F5@mti.sgi.com> jps@mti.sgi.com "James Salsman" writes:

>John McCarthy wrote:
>> 
>> I would guess James Salsman misinterpreted or misread the
>> Exploratorium poster.
>
>
[Snip, Someone else can deal with this]

>For terrestrial collectors, I revise from about five square 
>kilometers to about 100,000 (based on the up-to-date efficiency 
>and weather factors from other posters.)  That's a square 
>200 miles on each side, or about 1/20th the area of Saudi Arabia, 
>or 2/5th of Nevada.  Again, that's to serve the electrical power 
>needs of everyone on the planet, and it's all solid state, 
>zero-emission renewable (at least for the next 3 billion years)
>technology.


The silicon PV tecnology takes more energy to produce then it
can produce over the lifetime of the cell. Howether there is 
another way to do solar collectors on this scale. If you plant
a large number of fast growing plants and then burn them in a 
heat engine you will get a reasonable efficiency with no overall
pollution (Assuming combustion tempeture is low enougth to avoid 
NOx production). Of course you need water which may be difficult 
in the areas we are talking about. You will produce the same
amount of CO2 as was used by the plants. 


BTW.
There is a plant in florida? which uses direct solar concentrator
array to produce power. In the absence of sun light it uses gas to
rase steam. Apparently cost per KWh is comparable to other forms
of power generation. 

Just my $0.02
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