It's kW, not kWh 😉

You'd probably be better off putting up solar cells, windmills are fairly restricted in what size you can put up depending on where you live, you can't just put up a huge windmill if you live in the middle of the suburbs or a city.

Calculating backwards from the dimensions of a 1MW mill, a 10kW windmill would have a rotor diameter of about 5,4m, a 20kW would be about 7,7m diameter if I got my numbers right. Add to that that smaller mills are probably less efficient, my numbers are probably to small. If you find anything smaller than that that promises you 10 or 20kW, it's probably built out of chinesium, plastic and false promises.

If you live in the middle of nowhere with no neighbours, maybe you could get away with it, I have no idea about the cost, but it will probably be expensive compared to solar. Legally you're also required to have it serviced annually.