The link in the title is to a story at Wired about the proposed "Freedom Tower" for the World Trade Center site. It is to be very tall and will provide as much office space as the twin towers did. It will also have a bunch of wind turbines in the latticework between the top floor and the antenna base. These it is hoped will provide 20% of the building's electricity.
The figure, of course is in kilowatt-hours: 2.6 million! That is in fact the theoretical output of only a 1-megawatt wind turbine. And this building will sport a whole series of turbines, so they're obviously going to be rather small. The picture in the article shows bigger ones in the center, flanked by smaller ones on the outside. (Their proximity to each other will probably cause interference, so the actual output would likely be very much less than the projected claim; and they would have to be shut down when ice is a possibility, or else risk throwing it all over lower Manhattan, which doesn't need more of that, thank you very much.)
So what, you say? Small rooftop turbines sound like an ideal choice in the city. They aren't expensive, they generate power right where it's used, and they can reduce some of the building's need from the grid. True enough, and this project is being hyped as a showcase of such urban use of renewable electricity generation (the building will also have solar panels).
But those tiny propellors 1200 feet up at the top of a massive building surrounded by other massive buildings amidst the dense urban roar will be used to promote jumbo-jet-sized turbines thump-thumping around on giant poles in rural areas, including unspoiled prairies and mountains.
