Xref: utzoo talk.politics.misc:8751 sci.misc:1247
Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!umd5!uvaarpa!mcnc!rti!xyzzy!owen
From: owen@xyzzy.UUCP (Karl Owen)
Newsgroups: talk.politics.misc,sci.misc
Subject: Re: greenhouse effect / solar power satellites
Message-ID: <737@xyzzy.UUCP>
Date: 1 Apr 88 17:59:29 GMT
References: <22678@bbn.COM> <5564@well.UUCP> <761@spdcc.COM> <4195@bloom-beacon.MIT.EDU> <763@spdcc.COM>
Organization: Data General, RTP NC.
Lines: 45

>, >!: eli@spdcc.COM (Steve Elias)
>! jfc@athena.mit.edu (John F Carr)

>!:     efficiency has nothing to do with the problem of thermal pollution.
>!Efficiency has everything to do with thermal pollution.  For a fixed power
>!consumption, efficiency determines the amount of heat generated relative to
>!useful power.
>       you are wrong, here.  both the 'useful power' and the 'waste heat'
>       end up in the environment as heat.  

Steve is apparently not reading what he is responding to, or is
unbeleivably slow to pick up the central idea here.  Note the phrase
"for a fixed power consumption".  Under that assumption, the less
efficent the power production, the more total energy must be liberated
to support the "fixed power consumption".  Thus, while it is correct to
say that both the "useful power" and the "waste heat" wind up in the
environment as heat, this is irrelevant to the point being made, which
is that for the more efficent process, the sum of these is smaller.

>!Adding heat will not raise the temperature
>!noticeably until the rate of addition approaches the solar flux on the earth.
>!Adding CO2 has already warmed the earth (the articles have numbers).  
>      yes!  my point is that hundreds of solar power satellites
>      WILL add energy on the order of the present solar flux!

Simple arithmetic makes this claim incredible.  The present solar flux
reaches earth through an effective window perhaps 1X10^8 square
kilometers.  For "hundrds of solar power satellites" to produce energy
"on the order of the present solar flux", each one would have to be 100
kilometers across.  As far as I know, proposals for SPS have satellites
with 1/100th of that surface area, and only a few tens of them, not
"hundreds".  And all this without even accounting for the fact that much
of the waste heat in this process would be released outside the
biosphere.

Certainly, the claim that SPS would necessarily create more thermal
pollution than competing ground-based systems involving solar,
biomass, petrochemical, or nuclear processes is nowhere nearly
established by anything Steve has put forward so far.

--
Nothing is so useless as a general maxim.
                                --- Thomas Babington
-- 

	Karl M. Owen			owen@dg-rtp.dg.com
	Data General, RTP, NC		...!mcnc!rti!xyzzy!owen