Ask a Sailboat Racer about wind (Score 1)

Much of this is common knowledge for people that sail. There is more wind at the top of the mast than at the bottom. Boats in front of you affect the wind you see in different ways. Sailing towards a land feature will change the wind direction and speed. In the simplest case building a wall in front of a windmill that is 90 degrees to the wind will increase wind speed at the bottom of the windmill. That's a win. Curved wall maybe buys you some velocity increase from slightly changing wind directions. But if the wind direction changes a lot, but not 90, or 180 degrees from the wall, you get "dirty air" (sailor term) from the wall and decreased performance from your windmill. I do like the idea of planting trees to create a windbreak for prevailing wind direction, but most windfarms I know of are in places where trees don't grow.