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From: jwm@stdc.jhuapl.edu (James W. Meritt)
Newsgroups: talk.politics.misc,sci.misc
Subject: Re: NOT greenhouse effect / solar power satellites
Message-ID: <163@aplcomm.UUCP>
Date: 31 Mar 88 14:07:28 GMT
References: <22678@bbn.COM> <5564@well.UUCP> <761@spdcc.COM>
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Reply-To: jwm@stdc.jhuapl.edu.UUCP (James W. Meritt)
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Organization: The Johns Hopkins University Applied Physics Laboratory
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In article <761@spdcc.COM> eli@spdcc.COM (Steve Elias) writes:
>In article <5564@well.UUCP> pokey@well.UUCP (Jef Poskanzer) writes:
>>reason Steve is full of shit.  As John Carr and others mentioned, most of the
>>inefficiencies in SPSs are off-planet.  The conversion from microwaves to
>>electricity is extremely efficient.  (Yes, 90%.  Not 80%.  Not 50%.)  And the
>     efficiency has nothing to do with the problem of thermal pollution.

To the contrary, efficiency has a great deal to do with it, if you are talking
about the heat produced where.  As I recall from the original posting,
one of the primary "efficiencies" discussed involved the absorption of
the light in the first place.  Everything absorbed will become heat,
eventually, so that is not really an issue.  The percent absorbed in
the first place, however, IS.  As given in the example, sand reflects
light and solar panels do not (mostly).  The reflected LIGHT goes back
into space.  Thus, solar panels trap energy into the earth/atmosphere
system that would ordinarilly be immediately returned into space.
This occurs no matter their ELECTRICAL efficiency ... in fact, it happens
even if they are merely black painted wood.

>   all energy
>   produced by solar power satellites would not otherwise enter the
>   earth/atmosphere system.  so your _____ arithmetic is pointless.
>   if you had done your _____ calculations properly, you would see that
>   solar satellites are infinitely worse than most other energy sources.

Initial statement concerning energy entering the earth/atmosphere system
is correct, unless it is running only while eclipsing the earth.
The arithmetic, however, is not pointless.  It demonstrated that:
1. We are very unlikely to produce sufficient energy to significantly
   directly increase the overall average temperature of the earth/sea/
   atmosphere system.
2. Importing electrical energy directly (in the form of microwaves?
   skyhook-type LLLLOOOOOOONNNNNNNNNNNNGGGGGGGG extension cord?)
   would provide energy without the indirect thermal problems associated
   with on-site generation by any means.  The waste heat associated
   with the generation of electricity by any means at any efficiency
   produces waste heat.  SPS will produce this waste heat outside of the
   e/o/a system, other methods produce it inside the system.  If you
   want the electricity  (and I notice you are not willing to do without
   simply by the fact that you are reading this) you gotta do something
   about the inefficiencies of electrical generation.  

>>For the few reasonable people out there: the CO2-induced "greenhouse effect"
>>is very very different, and is indeed a serious problem.  But of course
>>SPS wins there too.
 
>    jef -- you misunderstand my point completely.   jfc and  others out
>    there apparently do not.  and they are capable of civil discussion.
>    get lost.  take your silly arithmetic and silly 'one-f' and go
>    eat some microwaves.

If the point is "thermal pollution is a problem", I concur that it is
an interesting problem.  As the arithmetic displays, however, it is
not a hazardous problem except to those in the immediate vicinity of
the power sites.  (or an advantage, depending.  There are some
tropical fish and reptiles living in New York:  seems they wound up
in a power plant cooling pond, which was warmed up to tropical 
temperatures by the power plant.  If it goes, they go.)

Now for my major gripe with the general trend of this discussion.
flaming, while it may satisfy your ego, does not advance your ideas.
And you have a tendency to discredit yourself by an hominem (sp?)
attacks.  I really expected more.
Do you notice something odd about the sentence containing "civil
discussion" followed by the phrase "get lost", both followed by
one containing the self-evaluated "silly" twice and an absurd
suggestion?

As a question, what do you estimate the electrical requirements of a 
planet to be that would produce a thermal problem to fit within the
"dangerous" (which is?) region?



Disclaimer: Individuals have opinions, organizations have policy.
            Therefore, these opinions are mine and not any organizations!
Q.E.D.
jwm@aplvax.jhuapl.edu 128.244.65.5