The solar flux at earth orbit is on average (because the earth's orbit is not circular and the solar output is not constant) more or less 1370 W/m2; The Earth's radius is 6.378 X 10^6m; The Earth's albedo is around 0.3. So the total incident solar energy that is obstructed by the earth's disk and that is not reflected back out into space is solar flux * Area of earth's disk *albedo = 1370 W/m * 1.278 * 10^11 m2 * 0.30 albedo = 5.2499373183089.4 * 10^14 watts
So according to my quick back of the envelope calculations planet earth receives a solar flux on average of well over500 Terawatts after factoring in the energy reflected back into space. And that is just the energy that is intersected by our planets disk... imagine how much energy a Dyson sphere could harvest. ________________________________ From: LizR <lizj...@gmail.com> To: everything-list@googlegroups.com Sent: Wednesday, February 12, 2014 4:25 PM Subject: Re: Edging closer to nuclear fusion... On 13 February 2014 12:44, Chris de Morsella <cdemorse...@yahoo.com> wrote: We all do use it already -- even as we burn the fossil fuel banked in coal seams and gas & oil bearing formations, all of which ultimately exists because a long time ago some plant had done the work of transforming a minuscule portion of the energy of flux put out by our fusion energy source in the sky during that long ago era into hydrocarbons with a potential chemical oxidation energy stored in them. >Yes, sorry, I should have said exclusively, or more or less so. (I don't >consider burning hydrocarbons to be a useful way to use sunlight, because of >the by-products.) The Sun lavishes something like 10,000 times more energy on >Earth than the entirety of the energy used by human civilisation, I believe? >Certainly a lot more than we need, even if you knock off the amount used for >keeping warm and so on (most of it goes back into space anyway, I think). -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
