Don't quote me on this, but I recall reading that there is a layer of air at ground level that is very turbulent/choppy due to it's interaction with the ground which makes it terrible for wind power generation.
Only the generator is at the bottom, the power still comes from the upper part of the structure and is
transferred mechanically, I would assume.
What the parent-post means is that the machinery of the generator is positioned at the bottom below the blades instead at the top of a tall column behind the blades. Presumably this creates some savings in terms of construction and maintenance.
perhaps also aerodynamics relative to a big generator blob right at the top?
VAWTs do ok in turbulent conditions. HAWTs don’t like it because they need a consistent stream of air flowing in one direction.
General fluid speed is ~0 at any surface and has some gradient to the proper wind speed as you get some distance away from the surface.