Okay lets see 660gh x 12 = 7920 gh or 7.920th. at about 20000 watts
and a tweaked s9 using brains software will do 8th at about 670 watts
so op WTF are you thinking?
you want to spend 20,000 watts an hour vs 670 watts an hour.
For what possible reason?
Free power is fine but if you have free power buy some s9's and run them instead.
If you have 20,000 watts an hour to burn.
Buy 2 s9's and run them at 14th each at 1300 watts = 28000th for 2600 watts.
I have s9's for you if you are USA based.