Andy Champ wrote:

unlike the output of windmills which is much less
predicable and close to random in distribution through 24 hours.

Damn. Can't find out who wrote that...

... but. You'll find there is a diurnal pattern in the wind. It often
goes light around sunset, especially in areas where there's a sea breeze
powered by temperature difference between the land and the water.

only at ground level

Up a 100ft its blowing just the same.

Andy.