Large wind turbines generally have three blades, while small wind turbines have two blades. Large wind turbines require stable rotational speed, so there is a set of wind blade wind angle adjustment mechanisms inside. Small wind turbines do not have this mechanism because they are simple. Fewer and longer blades can utilize a larger windward area, and the longer blades are equivalent to the length of the moment arm. Prevent the increase in the number of blades required due to short blades.
This is the fatal power shortage of old-fashioned wind turbines. The blades are few and long, with a cantilever beam structure, and the roots of the blades bear huge stress. The roots of the leaves are very thick and heavy. There are few blades, low rotation speed, and a lot of air leakage. Where does the 40/100 efficiency come from?
It has fewer blades and fast rotation speed. Considering the balance of the center of gravity, it is only suitable for small ones.