Factories with no need for humans, saving on heating and lighting costs.
Management guru Warren Bennis has said:
"The factory of the future will have two employees: a man and a dog. The man's job will be to feed the dog. The dog's job will be to prevent the man from touching any of the automated equipment."Fanuc, for example, does it. They have a building where robots procreate, robots making robots.
It gets creepier though, there's another reason that the lights are out at some of these plants, here's Mitsubishi: