So firstly, I wanted to test out how an all lower-cased title would look.

Second, I was watching an episode of "Life After People" with my family and they talked about this billboard in Time Square that's run off of wind turbines and solar panels. After 2 sec of searching, I found a NY Times article on it: http://www.nytimes.com/2008/11/15/nyreg ... board.html

I did a small paper on vertical axis wind turbines and wind in urban environments, so I find this a great proof of concept. The sign isn't electronic like every other one in Time Square, it's just a painted billboard with 16 300-watt floodlights, so it uses 4800 W, or 4.8 kW while the turbines output an average of 22 kW, so it seems to find a very nice energy balance. Is my math right?

I saw that episode too! I actually thought of you Chris when I saw it. Maybe we have a telepathic connection or something. Weird.

Anyway, are these turbines being used anywhere else in the world? I remember seeing them in various concept designs, but I've never seen them implemented.

No, no one really uses vertical wind turbines, they don't have the efficiencies that horizonal-axis ones do, but they're good for turbulent wind that quickly changes direction (like in a city). There are smaller versions sold as residential models, but I don't know how many people are biting. But in the article, they mention the company that made these particular ones and said they were custom made.

one of the big problems with residential turbines is (i think) getting them high enough to be in smooth wind, regardless of whether they're vertical or horizontal. it's hard to build a tower high enough in a lot of places.
Is the turbine output 22kW rated capacity (meaning that with a 20% capacity factor it's right around the 5kW the sign wants)? and what's their cut-in speed?

The turbines for the billboard were custom made. Collectively, the article states that they output an average 22 kW and that there's an average wind of 10 mph. I think the articles basically states that the cut-in speed is 5 mph. That average 22 kW comes from 16 turbines on 4 axes, which is kinda pitiful actually (the 16 turbines part, not the 4 stacks part).