"... a French company called NewWind has been developing aesthetically pleasing, tree-shaped turbines meant to run silently within cities, at ground level. The innovation is simple named “L’Arbre à Vent” or in English “The Wind Tree”. The tree features 72 artificial leaves where each leave is a small turbine that rotates around a vertically directed axis. The leaves are very light-weight, which means that they can generate power from very small amounts of wind. Actually it takes nothing more than 4.4 mph (2 meters/second) of wind for them to function, and this is amount of wind is equal to a gentle breeze."
Photo: Michaud LARIVIERE, http://www.cite-telecoms.com/decouvr/arbre-a-vent/
Via Miguel Prazeres, Ashish Umre