From: utzoo!decvax!harpo!zeppo!whuxlb!ech Newsgroups: net.space Title: Re: Re: Reactors on the Moon - (nf) Article-I.D.: whuxlb.574 Posted: Fri Sep 17 15:44:48 1982 Received: Tue Sep 21 09:29:51 1982 #R:sri-unix:-330400:whuxlb:9300003:000:1162 whuxlb!ech Sep 17 15:24:00 1982 The observations about the relative advantages of solar over nuclear power on the moon are persuasive, except for one glitch: the sun shines only about half the time, and when it does shine you have to "point" your collectors at it for maximum advantage (simply spreading a sheet on the more-or-less horizontal means you wind up with a power uptake that looks like a sine curve with the negative side clipped to 0). Indeed, the solar arguments are most persuasive only when the sun shines almost all the time, e.g. in orbit. This is the tremendous advantage of the L5-style space colony: the sun is almost always there to tap, and keeping the collector aimed at it is fairly easy in freefall. The major problem with solar power on planetary surfaces remains the lack of effective energy storage technology. The need for energy storage transcends solar needs, of course: any electric utility would like to be able to run its generating plant at a constant rate, storing the surplus at times of low demand and tapping it for peak demand. Solar power for mining the moon has the dual problem: a constant demand and a fluctuating power source. =Ned Horvath=