The main question has been answered in comments, I think, but to further put things into perspective:

The total energy of Earth's magnetic field is very roughly our current energy consumption over a thousand years. This on one side sounds seriously huge, it's enough to boil away the Caspian sea (twice, actually). On the other hand, it is not at the absurd scales most other cosmic things are (e.g. dismembering the entire planet, solar energy output, or worst, supernovae), we could get there if we very very seriously want it even with current tech.

(I hope I remembered the total energy correctly, as modern Google is utterly useless when trying to verify them; all other numbers have been re-calculated.)