The Dyson Harrop satellite (DHS), however, draws energy from the solar wind’s electrons, using the Sun’s high energy photons only to eject the electrons once their useful electronic energy has been collected.
DHS can provide power at a rate that increases proportionally to the square of current through the Main Wire. A current of 0.444 A would produce ~1.7 MW of power, while tripling the current produces about 10 times more power. A 1-kilometre-long wire and a sail 8400 kilometres wide could generate roughly 1 billion billion gigawatts (10^27 watts) of power, which is 100 billion times the power humanity currently requires. Dyson-Harrop satellites rely on the constant solar wind found high above the ecliptic – the plane defined by the Earth’s orbit around the sun. Consequently, the satellite would lie tens of millions of kilometres from the Earth. To beam power from a Dyson-Harrop satellite to Earth, one “would require stupendously huge optics, such as a virtually perfect lens between maybe 10 to 100 kilometres across. A smaller version of this satellite could help power some space missions. It could generate power for something like the Ulysses spacecraft, which went around the poles of the sun.
DARPA is trying to make lasers in the 150 KW range and trying to get to power density of < 5 kg/kw. So besides the focusing problem is the challenge of making lasers or microwave transmitters of the needed size and in volume. It should be relatively cheap to construct, given that the system is composed almost entirely of copper and doesn’t require circuitry. Later versions could use carbon nanotubes (when they are cheaper and made in higher quantity) for lighter wires that can handle more current. Our Sun emits a solar wind of only ~10^-14 MS/yr, and the 0.444 A model of the DHS merely diverts ~10-14 of the Sun’s solar wind (~10-28 MS/yr).
The Sun (A) emits a plasma half-composed of electrons, half of protons and positive ions (B). Electrons are diverted (via Lorentz force from a cylindrical magnetic field (C) from their radial trajectory towards the ‘Receiver’ (D), a metallic spherical shell. When the Receiver is “full”, excess electrons are diverted through the hole in the Sail. The large positive potential on the Sail drives an electron current through the ‘Pre-Wire’ (E), which is a long, folded wire designed to cancel out the magnetic fields of the current towards the Sun. Once it reaches the end of the Pre-Wire, it travels down the ‘Main Wire’ (F), creating the magnetic field (C), which makes the field-current a self-sustaining system. The current passes through a hole in the Receiver and then through the ‘Sail’ (G), passing through the ‘Inductor’ (H), and the ‘Resistor’ (I), which draws off all of the electrical power of the Satellite to the ‘Laser’ (J), which fires the electrical-turned-photonic energy off to a designated target. Drained of its electrical energy, the current continues to “fall” to the Sail (G). Here, electrons will stay until hit by appropriately-energetic photons from the Sun, at which point they will leap off (K) from the Sail towards the Sun, and then be repelled by the magnetic fields (C) and excess solar wind electrons (B) away from the Satellite, imparting kinetic energy to the Satellite away from the Sun
The search for Dyson Spheres has been propelled not only by the hope of discovering intelligent alien life, but by humanity’s ever-increasing need for energy. However, the Dyson Sphere is not a practical design, requiring too much matter to build and too much energy to stabilize. Here we discuss the various designs of a Dyson Sphere and propose the Solar Wind Power (SWP) Satellite, a simplistic, self-sustaining system that draws power from the solar wind and uses a laser to fire energy to collectors (on space stations, bases, etc.) positioned anywhere in the Solar System. While a small SWP Satellite can provide an estimated 2 MW of power, larger (or networks of) satellites could provide terawatts of power or more. The cost of the SWP Satellite would be relatively cheap – it primarily consists of shaped copper, with only a few complex systems onboard. Detection of such a satellite would be difficult using current technology, because at this time we can only detect solar wind deviations of up to 10^−13 MS yr−1, while a 2 MW satellite would only divert 10^−34 MS yr−1. Thus, only very large SWP Satellites could possibly be detected.