12% increase in what efficiency?
in any case, regarding twisting the blade, it should be simple to understand that the blade root and tip are not at the same angle.
but the difference changes according to the airspeed. simply rotating the entire blade doesn't preserve optimum blade twist.
one example would be for a kaplan water turbine, the blade root is at 20 degrees, the tip at 10 degrees
but when you want the blade root at 45 degrees, the tip needs to be 22.5, a difference of 22.5 degrees, not 10.
>this was my first reaction reading the title "new twist in wind blades"