The Earth's magnetic field, like any magnetic field, has an energy density of B²/2*µo or about 0.88mJ/m3, which is insignificant (and we have no idea how to recover it).
That weak field comes from a huge magnetic dipole, so the question should be can we extract energy from that dipole? Well that dipole may only create a weak
B field at the earth's surface, but the
A field there is certainly not weak. At the equator it is something like 200 Weber/m and it runs E-W (to get an appreciation of this you would find that value of
A field at the central cylindrical surface of a huge fully-magnetized piece of iron that is 400m in diameter, 4km long and weighing 4 giga-tonnes!). So is it possible to use this huge field?
It is well known that an
A field that is changing with time creates an
E field,
E=-d
A/dt (1)
and a charge
q in that field will endure a force
F=
q*
E. (2)
Combining the two effects gives you
F=-
q*d
A/dt (3)
which is classical transformer induction.
In some EM theories
q*
A is seen as a form of canonical or hidden momentum that is added to the mechanical momenum m*
v. Then since a force develops from rate-of-change of momentum
F=-d(m*
v)/dt-d(
q*
A)/dt (4)
is the force developed when a body loses momentum. The back force you feel holding a hosepipe is due to mass escaping at constant velocity given by
F=-
v*dm/dt which is one derivative of the first term in (4), the other
F=-m*d
v/dt being classical mass inertia. Similarly if a body residing an an
A field loses charge a force
F=-
A*d
q/dt (5)
will be developed which is one derivative of the second term in (4), the other being the classical transformer induction (3).
This topic has been discussed before in relation to some form of motor, but not with regard to the TPU, see
https://www.overunityresearch.com/index.php?topic=3395.0For the TPU it could transpire that the inner coil wound onto a cylindrical former made of cork is caused to vibrate in some simple mode (hence the soft cork), the force coming from the earth's
A field via (5). This requires other coils to induce alternating voltage (hence surface charge) onto the inner coil. Now with vibrations set up and the force coming from an external source, we can use the vibrating wires as a generator in classical
v X
B motional induction, with the
B coming either from local PM's or from other local coils. Is this worth further exploration?
Smudge