For a used Antminer S9 you need average total electricity price to be below $0.08/kWh to have break-even in 1 year, it seems. In year 2 you will have earned abo

For a used Antminer S9 you need average total electricity price to be below $0.08/kWh to have break-even in 1 year, it seems. In year 2 you will have earned about $600. If you look at GPU mining, a single RTX 3090 setup (assuming you already have a computer to put it in) requires electricity cost below $0.05/kWh to have break-even in 1 year.