In reply to Michel Jullian's message of Thu, 14 Dec 2006 10:21:21 +0100: Hi Michel, [snip] >This made me wonder how much electrical energy would be thus stored in this >Earth-atmosphere capacitor: > >C*V^2/2=q*V/2 = (28 440 * 300 000) / 2 = 4 266 000 000 = 4.3*10^9 J
You forgot to square the voltage. ;) The correct answer is 1.28E15 J. Still only a tiny fraction of what we use on a daily basis, but then how do we know it takes the Sun a whole day to charge this capacitor? > >This is two orders of magnitude less than the 4.3*10^11 J order of magnitude >estimate at page 20 of this physics lecture material (a good reference for >capacitor calculations BTW): >http://galileo.phys.virginia.edu/classes/632.ral5q.summer06/Lecture1-16_Powerpoints/lecture_5_mat/PHYS632_C5_25_Capac.ppt > >This energy, according to the same source, is renewed daily by the sun (king >sized photovoltaic module ;). But even their much higher estimate is still 2 >million times less than the world's daily energy consumption (about 10^18J), >very disappointing! > >Michel Regards, Robin van Spaandonk http://users.bigpond.net.au/rvanspaa/ Competition provides the motivation, Cooperation provides the means.
