At it's simplest is a ring with power flowing through it, the power requirements would be minimal, 1 Tesla needed and a deflection of a fraction of a degree. I

At it's simplest is a ring with power flowing through it, the power requirements would be minimal, 1 Tesla needed and a deflection of a fraction of a degree. I've seen estimates in the single digit MW range which we build solar plants on Earth for a few million each. Power generation is somewhat irrelevant, getting the material up there and maintaining it will be the real monetary challenge. Read the link at the end of the popsci article. There's a huge amount of research going into generating magnetic fields for spaceships and inhabited bases.