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From: Ordania-DM@cup.portal.com (Charles K Hughes)
Newsgroups: sci.energy,sci.electronics,sci.physics,sci.space
Subject: Re: solar cells
Message-ID: <37550@cup.portal.com>
Date: 4 Jan 91 02:33:50 GMT
References: <37448@cup.portal.com> <1991Jan2.015717.23554@amd.com>
  <37487@cup.portal.com> <88637@lll-winken.LLNL.GOV>
Organization: The Portal System (TM)
Lines: 120

>
>	The issue of chemical vs. nuclear poisons was brought up yet
>again. I feel that this anti-nuclear allergy that too many people have
>will someday be remembered as one of the irrational phenomena of our
>time. But I doubt that it is worse that the turn-of-the-century
>enthusiasm for patent medicines made from radium and other radioactive
>materials.

  I don't think the "allergy" is irrational given 3-mile island, 
Chernobyl, lists of missing nuclear fuel, 55 gallon drums of nuclear waste
carelessly spewn across the ocean floor (& associated tales of using rifles
to shoot holes in drums that wouldn't sink), etc.
  Radioactive materials are dangerous to complex organisms, and the more
RM that is around, the more dangerous it is (the probability of an 
accident increases).

>
>	As to chemical poisons being decomposable, that depends on
>what kind of chemical poison. Heavy metals cannot be chemically
>decomposed. And some chemical poisons are difficult to decompose, such

  Heavy metals don't need to be decomposed - they can be refined and reused.

>as chlorinated hydrocarbons. The persistence of certain pesticides
>like DDT should be well known. True, DDT and other such
>non-biodegradable substances can be burned at high temperature, but
>burning at high temperature is just that.

  What we can make, we can unmake.  I don't think the environment should be
responsible for decomposing the unnatural chemical compounds that we
introduce into it.
  The cost of "unmaking" is very high, mainly because it is cheaper in the 
short run to just discard the waste byproducts.  In the long run, these
byproducts will come back to haunt us - cf. Lovecanal, DDT, etc.

>
>	I remember some years back that the EPA was hoping to burn
>some toxic wastes in a ship at sea, but some environmentalists didn't
>like that idea very much.

  I can't imagine why.

>
>	I keep on being amazed by the anti-RTG movement. They complain

  What is RTG?

>that those who send up RTG's on spacecraft have not done comprehensive

  A nuclear power plant?

>studies of possible alternatives. Yet I wonder if the anti-RTG people
>have done anything similar. Consider the difficulties of doing
>maintenance on a spacecraft, which usually cannot be brought back to
>its designers. Millions of dollars and months of work go into
>designing some spacecraft, so it is important that they be likely to
>keep on working. One should try to use components that need as little
>maintenance as possible, and RTG's fit the bill very well. They are
>continuously "on" and have no moving parts. Solar cells are one common
> [solar cells degrade]
> [focused sunlight systems require lots of moving parts]
>	Chemical reactions are out of the question. Buth fuel and
>[good reasons deleted]
>moving). Batteries have a minimum of moving parts, but they usually
>have a very low available power to mass ratio (ask any designer of a
>battery-powered car). Fuel cells are relatively efficient, but even
>they have moving-part problems, and they require liquid hydrogen and
>oxygen, which must be kept away from heat. Systems using combustion
>can use fuels and oxidizers that are liquid at room temperature, but
>they also suffer from problems with moving parts -- consider typical
>turbines and piston engines.
>
>	So either solar cells or RTG's are the way to go for
>spacecraft. I presume that this is the standard argument.

  Hmmm...why not ground or space power generation for those satellites
that orbit the earth & moon?  Deep space satellites are of little concern
here because once they leave, they're gone for good.

  RTGs (assuming they are small nuclear plants) are dangerous in any orbit 
that decays before the nuclear fuel becomes non-radioactive.

>
>	In fairness to opponents of nuclear energy, I think that there

  This is war buddy....you know the saying... :)

>
>	And on the issue of safety, one should ask what kinds of
>critical tests are possible. It is much easier to perform really tough
>tests on an RTG than on a nuclear reactor, so one may feel more
>confidence in their safety.

  I still don't like the idea of a blob of nuclear goop falling from the 
sky into my living room. :)

>
>	And another possible difficulty with solar cells -- how much
>energy does it take to make them? They would not be too good if the
>amount of energy needed to make them was only equal to their output
>for several years of running. Has that question ever been addressed?

  If the energy is free, who cares how much it took to make them?

>
>
>$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
>Loren Petrich, the Master Blaster: loren@sunlight.llnl.gov
>
>Since this nodename is not widely known, you may have to try:
>
>loren%sunlight.llnl.gov@star.stanford.edu

  The real question (as I see it) is the *TRUE* cost.  Burning fossil fuels 
is cheaper than solar, nuclear is cheaper then solar, almost everything
is cheaper than solar if only the current fuel costs are looked at.  If the
total cost of burning fossil fuels, using nuclear energy, etc is 
totalled, solar will come out the clear winner.

Charles_K_Hughes@cup.portal.com