It seems to me that building one of these Solar Chimney on just a flat piece of ground is the most expensive place to build one.
Where I think one needs to be sited, is a spot with a wide empty area of land right next to a tall mountain peak. That way the collector can be built on the flat ground and the chimney can be built right up the side of the mountain peak right on the ground. That would bring the cost way down and get rid of the eye sore of a tall tower.
Seems to me that Colorado and California should have sites that fit that description.
We need to think of these power plants like we think about hydroelectric plants. Finding the right site is everything.