generating power

I’ve been reading recently abour various “unusual” power-generation methods. One of those that I’ve seen mentioned in several places is the solar updraft tower.

After having read about that, I wonder why more industrial steam stacks don’t utilize something similar: if you’re throwing away the steam, couldn’t you put a VAWT or other energy-capturing device in the tower to collect some chunk of that energy back either to the plant itself, or to the grid?