The wire contains the potential for electricity. The magnetic fields surrounding the magnets change the polarity of the atoms in the metal, thus causing electrons to be released. The faster the magnets spin in the metal coil, the more electrons are released and the higher the voltage created by the generator. More coils of wire will create more voltage. If your generator isn't producing electricity, try more coils of wire and ensure that the wire isn't broken or shorting out because of poor insulation.