What kind of windmills are these?

Question

There are some new type of windmills being used in a major city....they are made a different way than the ones you see in California on the wind farms....they stand vertical and shaped like a spiral....anyone know what they are called?

Answer 1

Vertical axis windmills have been around for a while - making them efficient and cost effective in manufacture has required a lot of computer work.  

http://www.windpower.org/en/tour/design/...

http://images.google.com/images?sourceid...