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From: eli@spdcc.COM (Steve Elias)
Newsgroups: talk.politics.misc,sci.misc
Subject: Re: efficiency / greenhouse effect / solar power satellites
Message-ID: <774@spdcc.COM>
Date: 4 Apr 88 16:17:38 GMT
References: <22678@bbn.COM> <5564@well.UUCP> <761@spdcc.COM> <4195@bloom-beacon.MIT.EDU> <763@spdcc.COM> <2997@sfsup.UUCP> <768@spdcc.COM>
Reply-To: eli@spdcc.COM (Steve Elias)
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Organization: S.P. Dyer Computer Consulting, Cambridge MA
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John -- i'm not missing the points you make below.  though maybe we should
consult with Jef in order to see what my beliefs are.

dealing with increased power demand is the crux of the issue...

my contention is that to meet a large increase in power demands with solar
power satellites will add something on the order of one percent or so to 
the total energy flux that the earth receives.  i believe i am accurately
stating this theory as i learned it from Frank Drake.

if one accepts the premise that we do have the potential to need so much power
such that many high capacity satellites would be necessary -- we do have to
argue about the effects of this increase in solar flux.  it may be a small
percentage increase -- but it will occur continuously.  

this leads me to reiterate my question about the atmosphere's reaction to 
long term increases in solar flux...  we've been told by an atmospheric
scientist that the atmosphere reacts quickly to localized increases in 
thermal energy.  i don't think there is one 'proven theory' as to how
it would react to a long term global increase in solar flux.  

In article <4288@bloom-beacon.MIT.EDU> jfc@athena.mit.edu (John F Carr) writes:

>You are missing the point: SPS will not be put up just for fun; no one
>will say, "I want to launch a 500MW SPS, whether or not anyone will buy
>the power."   We will only use SPS if there is a demand for the power.
>When demand is predicted to exceed supply, there are only two choices:
>increase supply or reduce demand.  Decreasing demand is not practical,
>and may not be possible.  So, we are left with the decision, "How do we
>generate the extra power?"   The amount of heat which will be generated
>to produce this power is P/eff.  The power consumption sets a lower bound
>on heat, but efficiency is important.  (Assuming there is agreement that
>demand for power will increase) we must assume fixed generating capacity,
>and argue the relative merits of different systems.  How are earth-based
>systems better?  I believe that, considering only thermal and poluution
>problems, they are not.  Building a heat engine on the earth will also
>add heat to the environment that would not otherwise be present.

	heat engines which use energy already present in the atmosphere
	or elsewhere on earth would not add net heat to the environment...

	agreed?  i'm not saying these power sources are necessarily the
	'best' -- just that they do exist...