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From: KING%KESTREL@sri-unix.UUCP
Newsgroups: net.space
Subject: Light Antennae
Message-ID: <12222@sri-arpa.UUCP>
Date: Wed, 8-Aug-84 16:47:00 EDT
Article-I.D.: sri-arpa.12222
Posted: Wed Aug  8 16:47:00 1984
Date-Received: Fri, 10-Aug-84 08:14:52 EDT
Lines: 43

From:  Richard M. King 

	I don't see why storage should be considered impractical, since it
is already being done on a large scale.

	We could, for example, only use hydro at night or on cloudy days,
doubling or more the amount you get from a given river.  (Less power is
used at night than during the day.)  The fact that an electric car would
usually never need to be recharged (A roof+hood area of 3-4 square meters 
gives about 2KW at noon; if the car has a duty cycle <10%, and most do, it
would never taste an electric outlet!) might make them a winner finally.  
Solar shingles would be a real possibility.  (Note that converting sunlight
to electricity and using resistance heat is more efficient than most solar
collectors, if you believe the 75-80% figure.  Also, the efficiency of a
thermal collector falls proportionally to the insolation (virtually nil on a 
cloudy day), and this wouldn't.

	An article in Technology Review of about 1 1/2 years ago gave about
3-4 cents/KWH as the cost of the home storage unit (Flywheel, Kevlar, ball
bearings, permanent magnet motor/generator, evacuated) and approx 10 cents/
KWH for the collectors.  (This is from memory; correct me if I'm wrong.)

	With the cells so cheap and efficient we can afford to provide enough
to power our load on cloudy days!  

	To summarize, the major uses of energy can adapt well to this source:

ground transport	electric cars with receiver roof
domestic		thermal (600 degree cast iron stores 20 KBTU/cu. ft;
				you need a 4 foot cube to heat a house for
				48 hours)
			electrical (flywheels, batteries, whatever!)
commercial		easier than domestic; less happens at night
heavy industry		store the product!  (Seriously, we would need twice
				as much (say) aluminum smelting capacity to
				meet America's need as we do now (assuming 
				existing plants run at night - do they?) 
				but the major cost of Aluminum is the
				electricity.

	These comments were jotted down very quickly - pardon any inaccuracies.

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