In reply to Jed Rothwell's message of Tue, 28 Sep 2010 17:16:40 -0400: Hi, [snip] >Now here's the kind of solution to energy crisis I'd like to see. >Space-based systems capable of producing 100 billion times more power than >we now consume! With a collection sail 8400 km wide. >
I have run similar calculations before, and I think they are off by a factor of about 100 billion. >The only problem is that you have to locate it far from earth. Actually the Earth itself is already such a magnet (which is all a current carrying coil is). > >See: > >http://www.newscientist.com/article/dn19497-outofthisworld-proposal-for-solar-wind-power.html > >QUOTES: > >Forget wind power or conventional solar power, the world's energy needs >could be met 100 billion times over using a satellite to harness the solar >wind and beam the energy to Earth though focussing the beam could be >tricky. . . . > >["Tricky" hardly begins to describe it!] > >. . . The concept for the so-called Dyson-Harrop satellite begins with a >long metal wire loop pointed at the sun. This wire is charged to generate a >cylindrical magnetic field that snags the electrons that make uphalf the >solar wind. These electrons get funnelled into a metal spherical receiver to >produce a current, which generates the wire's magnetic field making the >system self-sustaining. If you focus electrons onto a metal sphere, you get a sphere that builds up a space charge. Eventually the space charge is so strong that no more electrons can be added. For a current to flow, they have to have somewhere to go. Furthermore 99.99 % of the energy in the solar wind is in the protons, not the electrons (because they both travel at the same speed, but the protons are way more massive). > >Any current not needed for the magnetic field powers an infrared laser >trained on satellite dishes back on Earth, designed to collect the energy. . ..or evaporate cities. >. . > >. . . A relatively small Dyson-Harrop satellite using a 1-centimetre-wide >copper wire 300 metres long, a receiver 2 metres wide and a sail 10 metres >in diameter, sitting at roughly the same distance from the sun as the Earth, >could generate 1.7 megawatts of power . . . > >A satellite with the same-sized receiver at the same distance from the sun >but with a 1-kilometre-long wire and a sail 8400 kilometres wide could >generate roughly 1 billion billion gigawatts (10E27 watts) of power, "which >is actually 100 billion times the power humanity currently requires", says >researcher Brooks Harrop, a physicist at Washington State University in >Pullman who designed the satellite. . . . Either Brooks Harrop or the reporter needs to go back to school. 1E27 (not 10E27) Watts is 3 times the entire power output of the Sun. > >. . . but there is one major drawback. There's a lot more than one. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/Project.html
