Think of it, the Earth itself is always spinning at about 1660 Km/Hour near the equator. That is a lot of energy that could be tapped.

My idea has some pre-requisite's however:

Space Elevators, for getting the construction material to orbit cheaply.

Microwave energy transmission/Laser energy transmission.

Superconduction wire, a single wire thousands of kilometers long.

The concept is simple, and has even been discused in various forms. My variant has a few important differences.

The 'Sky-Wire' is simply a loop of superconducting wire run around the earth in orbit, where the maximum gain from the earths magnetic field can be attained. (probably far from the normal satelite orbits, and probably further out than geosynchronus)

The systems itself works by a simple magnetic dynamo effect. The ring of wire is simply rotated counter earth-orbit spin wise. As it passes thru the magnetic field lines of the earth it develops a huge charge, which is transfered by Microwave transmission points along the wire to Space-Elevator recieving stations. There are multiple recieving stations (space elevators), along the earths equator as the Sky-wire rotates the transmission points aim at the next reciever in the line-of-sight.

There are several problems I will attempt to address as well.

The sky-wire will incurr drag from particles coliding into it, and as it rotates against the earths magnetic field. The solution to this is simple, feed power INTO the sky-wire to speed up its rotation again. (turning into a giant motor)

Also Sky-wire may just overload and vaporise itself. (uhm, bigger thicker cables then... although a perfect super-conductor could absorb HUGE amounts of current.)

But beyond those problems, this system should work. It's certanly NOT violating any of the laws of thermodynamics, as technically its converting the Earth's orbital kenetic energy itself into current by utilizing the magnetic field of the earth... so it would slow earths orbit by some small ammount. (not likely to be noticed in millions of years)

This I would think is as close to free power as possible, without some really exotic effects like vaccum energy or black holes.
-- Melchior, Mar 06 2005

David Brin http://www.davidbrin.com/tankfarm1.html
[normzone, Nov 21 2006]

//The ring of wire is simply rotated counter earth-orbit spin wise//

How are you planning to accomplish this simple rotation? Whatever it is you are using will be the motive power in this generator, not the Earth's rotation. IF you were somehow fixing the ring of wire to the moon, or something equally difficult, this might work, but I doubt it would make a profit. Where has this been "discused"?
-- baconbrain, Mar 06 2005


Lots and Lots of Ion thrusters, for the rotation.

Also the rotation is optional. The Sky-wire could also be static in space (relative to the earth) and still generate power. I was thinking about having the ability to use it like a giant flywheel for excess energy storage on a grand scale.

Practical, perhaps...in a few decades or so. Also is Nuclear, Coal, Oil or Natural Gas and the associated support supply lines cheap? NO. It costs billions upon billions of dollars to build them, over a half century.

So this is comparitively quite cheap to build.

Also annother variation could be used like a giant antenna to catch the solar wind. (no idea about how practical THAT variant is however...)
-- Melchior, Mar 07 2005


You realise ion thrusters use electicity to run?

You can't beat the laws of thermodynamics, keeping the thing in place will take all the energy generated by it plus a little bit more.

The only way to could keep it generating is to hook it to something thathas a BIG difference in kinetic energy relative to Earth. ie. The Moon.

Also, yous have to build the thing on the Moon too (if you built it on Earth it would be stationary and hence generate no power).
-- Cats Whiskers, Mar 07 2005


Aren't we considering running the risk of inadvertently erasing all the magnetic media used on the planet? To say nothing of all the scout troops lost in the woods because their compasses no longer point properly to magnetic north ....
-- Soterios, Mar 07 2005


See the short story "Tankfarm Dynamo" by David Brin (if I'm not mistaken...)
-- cowtamer, Nov 21 2006


I found a link to the story.
-- normzone, Nov 21 2006



random, halfbakery