What is the advantage of the natural gas generator? Is it cheaper to power rigs via natural gas generator than with regulator electric?
You can get natural gas for as low as $100 per 1000 cubic meters, it is usually 10 000 kW*hours - $0.01 per kW*hour
Modern high-power turbine generators go as far as 42% efficiency so we can expect something around $0.03 per kW*hour
Not bad at all. But you should seriously consider how long it will take to ROI. If you have some need for secondary heat output (say hot-water for sale) it helps a lot in terms of ROI. Unfornutaly at the moment we got $300 for natural gas locally and $0.05 for electricity so I have no chance to proof my studies for-real :-(.