I got all the firewood for next winter cut yesterday. I find this very satisfying and go all smug about how 'green' we are in this regard. The wood grows on our property and trees either fall down from time to time or need thinning. I ought to be specific there. Our native bush is protected from any cutting, but taking fallen wood is okay, so we do. But the non-forested part is fair game and we let the odd tree grow here and there. They need cutting down every so often because otherwise we'd have all forest and no pasture (which would make the sheep unhappy). It is surprising how fast those trees grow.
If I were really, really green I would cut everything with an axe. This would probably make my wife quite pleased because she gets likes to see me chopping wood. But I'd never get it all done. So I use a chainsaw for most of it, though I split it with an axe, which is actually easier than the chainsaw.
So the wood gets all piled up in a covered area where it can dry nicely over the summer. Come winter it will be ready for burning. Our wood burner is connected to a wetback to the hot water cylinder so as well as heating the house it heats the water. During summer the hot water comes from the solar heater on the roof. The system depends on a small electric pump, just as the wood requires fuel for the chainsaw, so not completely green, but close. The fossil fuel energy used is minimal compared to the output and, of course, this is reflected in the costs ie very close to zero operational cost.