As I've been thinking about it more, the most disturbing part of the tower design is not the low energy yield. It's far more alarming that this gets picked up as an exciting direction for development (judging by the discussion of the tower on TreeHugger, Inhabitat, and similar sites).
I desperately want us to figure out how to capture energy from renewable sources in an economically viable manner. If we don't do that, we are royally screwed. However, the central problem is not, for example, that we have no land for wind turbines or solar panels. The core problem is low power density. We need to be putting up the most efficient, cheapest turbines we can build in the windiest areas, not less efficient turbines in a not very windy area with the added costs of building integration.
It's not a good idea that won't quite work-- it's a terrible idea that's headed in the wrong direction. It's morons like David Fisher (the designer) who give conservatives a reason to say "Bah, that renewable energy stuff is a load of crap."