650 for Chinese miners and how much for the rest? I think it maybe closer to 800 to produce 1 bitcoin, can anyone confirm what it truly costs?
It would depend where you are getting your power (and your cooling for that matter) - solar power to generate the funds and underground for insulation with venting to cool perhaps? (You wouldn't necessarily have solar power in colder climates, but then again perhaps you could have hydro power from the snow thawing into nearby lakes)