For your information. For th electical energy i pay 0.28CHF /kwh (around 0.35USD) and get back for the overproduction 0.06CHF/kwh (0.08USD)
Wow, that's an outright scam.

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Anyway, you missed a very important piece of info, which is how much power you got sitting on the sidelines? Let's just drop a random example of 3KW for 4 hours a day, or a total of 12kWh, you could sell that to the grid and make roughly $1 a day with no added investment or risk.
If you buy a 3KW gear instead and say it's an M60 170th costs roughly $2000 (not sure about tax and so on in your country) it makes 9$ / day or $1.5 every 4 hours, but then you already lose that $1 of selling the surplus, so in reality, you only end up making 0.5$ a day for $2000 investment that's a terribe one.
The 4 hours, the M60, and even the current profitability are all RANDOM. You may plot other numbers as you wish -- the logic stays the same; mining is not for you.