en http://en.wikipedia.org/wiki/Wind_turbine_design#Blades square of the radius of the turbine http://en.wikipedia.org/wiki/Wind_turbine_design#Blades size of wind turbines Wind turbine design 70 to 80% of Betz' law limit en square of the radius of the turbine Blade count size of wind turbines English Wind turbine design square of the radius of the turbine Blade count Wind turbine design square of the radius of the turbine wiki square of the radius of the turbine wikipedia Wind turbine design http://en.wikipedia.org/wiki/Wind_turbine_design Wind turbine design square of the radius of the turbine Wind turbine design square of the radius of the turbine Wind turbine design Wind turbine design Wikipedia: Wind turbine design Wind turbine design Wikipedia: Wind turbine design http://en.wikipedia.org/wiki/Wind_turbine_design http://en.wikipedia.org/wiki/Wind_tur... Wind turbine design square of the radius of the turbine Wind turbine design en Wind turbine design General wind turbine Wind turbine design Wind turbine design http://en.wikipedia.org/wiki/Wind_turbine_design Blade count http://en.wikipedia.org/wiki/Wind_turbine_design