You need to determine the wattage you'll need, the kWh consumption, the cooling requirements (natural/artificial and winter/summer) the amount of phases you'll need (no idea about amperage and how much each phase supports).
Also, difficulty increase overtime, forecasting in the BTC value (those last two factors are an unknown) and ultimately, ROI and profit.
I've already done all that and my last big hurdle is the electricity. With my planned minimum setup, I will be pulling a very liberal 1000 kwh/day.