Wind is awesome, but I don't think the total wind resource at tower-like heights is sufficient to wean the humans off fossil fuels; but I don't have hard numbers. Maybe power-to-gas is a solution.
Thank you very much for helping me explore this!
The numbers I've seen suggest that in the case of Germany, wind power can get you most of the way to a carbon free economy, but you still need to cover 1-2% of the land with solar panels (i.e. all roofs and a bit of land). Under the assumption that we also improve energy efficiency by insulating homes, switching to heat pumps, and switching to electric cars. Without those efficiency improvements it was unlikely that we'd have enough space. Under this scheme we'd need a little battery storage (for a day of consumption or so), and power-to-gas for longer periods of low generation.
I'm not sure whether he has talks in English, but Prof. Quaschning has some nice resources in German about this topic.
I was also surprised by that low capacity factor. Before doing the math I estimated maybe 100sqm per person. The US installation averages probably benefit a lot from the deserts and being much closer to the equator. Solar is pretty bad in Germany during winter.
I agree that we most likely don't need week long battery storage btw, but mostly because of wind energy that is also available at night and during winters. We can probably get away with just over night batteries and power-to-gas for long winters.