Well, it says right on the drawing that the wind always blows at 1000 feet, so perhaps the bottom fans are at 1000' and the thing goes up from there?

Probably a half mile high. They thought big in everything.
An interesting website is "Tales of Future Past".

http://www.davidszondy.com/future/futurepast.htm

That thing looks like at least a quarter-mile across at the base, and it appears to be almost three times as tall, so we're talking three thousand, maybe four thousand feet.

Meanwhile, at the actual wind farm closest to me, the turbines are a mere 217 feet tall.

Heh! Bird blenders! Birds for some reason are drawn to wind farms and seem to suffer from the collisions with big, heavy blades. The raptors them come in for the food and get blended also.

It would take a lot of wind farms to even make a small dent in the demand for electricity. It does not mean we should not try but it will take ALL of the new technologies in concert to even come close to helping.

Nuclear is now VERY efficient. Much more so than when it started out. As are solar cells. BUT, it takes a lot of them. ETOH is VERY wasteful - it takes 80% of the energy you get out of it to make it. Not very efficient. Plus the soil gets depleted pretty quickly unless crops are properly rotated. Not to mention the amount of water it takes - water to grow the plants, brew the mash, cool the boiled off vapor.

Here's something on it.

http://www.davidszondy.com/future/power/wind.htm