5. Blades

5.1 Sizing

As you can see, blade design involves a delicate compromise between aerodynamic efficiency, light weight, static strength, fatigue resistance and manufacturing cost.

Thus, the choice of profiles and their distribution across the span, the shape in plan (evolution of the chord as a function of the span) and the twisting of the blade must be carefully studied and adapted to the type of machine used. Thus, depending on the size of the wind turbine, the twist may differ significantly from one machine to another. In the case of a large, variable-pitch machine, you may be able to start the rotation with the help of the generator used as a motor, or by choosing the right blade pitch. On the other hand, for a small wind turbine with stall control, the...