MY summer power is 17 fucking cents a kwatt! but even at 17 cents my rigs earn money.
lets say 50 kwatts a day for 200mh that is 85 cents x 30 = 255 usd for power!
but right now 200 mh is earning close to 780 a month so I net over 500 usd a month.
So if the difficulty doubles and the price drops 40%, you will make a loss. The farms must have cheap electricity.
i concur if you have a big farm you need to build it on and exclusively with very cheap electricity, below 0.1 or even better, below 0.05
this is the reason why i never built a big farm, because of my fucking expensive electricity, i have the fund to build one but i can not risk the unprofitable times where the high electricity will kill my earning