Locked solar orbit. Interesting thought. That would solve some (not all) of the problems Mr. Goodwins raises. Of course it might create others.
If we put it somewhere between Mars and the asteroid belt, it would be a lot closer to its raw materials. ISTM to make a lot more sense to ship smelted metals or manufactured products than raw ore from there back to Earth. But at that distance, would a factory satellite have enough solar energy available to be useful?