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From: eder@ssc-vax.UUCP (Dani Eder)
Newsgroups: net.space
Subject: Re: Space Solar Power
Message-ID: <592@ssc-vax.UUCP>
Date: Tue, 1-Nov-83 12:25:38 EST
Article-I.D.: ssc-vax.592
Posted: Tue Nov  1 12:25:38 1983
Date-Received: Fri, 4-Nov-83 04:51:43 EST
References: <3408@umcp-cs.UUCP>
Organization: Boeing Aerospace, Seattle
Lines: 27


                                                   1 November 1983


I'd like to make two comments about the 'heat problem'.  First, it is true
that the energy finally produced by an SPS is eventually converted to waste
heat, ALL useful work produces heat as the final byproduct.  The advanteges
of SPS are that there is less waste heat initially, and it can be compensated
for.

     In a conventional power plant, only about 33% of the prime mover power
is converted into electricity.  Thus three times as much heat is produced as
useful energy.  With an SPS, the added flux in microwaves can be compensated
for because the recieving antenna or 'rectenna' on the ground is made of 
metal, rather than ordinary earth.  The net result is .4 units of heat for
each unit of useful energy with an SPS, versus 3 units of heat / unit useful
energy with conventional sources.

     Second, with ground based solar, either thermal or photovoltaic, you are
covering the ground with a very dark surface, thus increasing the absorbtion
of solar energy and causing the very problem you speak of.

                                               Dani Eder
                                               ssc-vax!eder
                                               Boeing Aerospace
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