That depends on how many sun hours or/and wind you’ve got at your place, how much panels you can install and of course how much light you’re using. I don’t have the knowledge to do the math on that.

Is there a free market to buy (sustainable) electricity from at your place? Or are you forced to buy from the local/regional provider?

Both will blow a lot of dirt and greenhouse gases into the atmosphere. What about solar panels or a windmill?