Why are the blades of wind turbines used for wind power generation so small[3]

I think it's a weight thing, because if it's bigger and the fan blades are heavier, they will be less likely to be blown away by the wind, so these should be the calculated volume and wind reception area which are most likely to be exploded. Because the fan blades of large-scale wind turbines are relatively large and cannot be compared with those of electric fans, and their weight is relatively heavy. If there are too many blades, the weight will become a brake on rotation.

As for the second question, I think 1 is cost, and 2 is to consider airflow. Maybe if they are close, the wind flow will interfere with each other.

Original, this cannot be modified. The principle is as follows:

1. There is no permanent magnet in the electric fan. The electric fan converts electrical energy into a magnetic field. Ae coil, then a The energized coil rotates under the action of this magnetic field, which is the motor of the electric fan;

2. The generator must have permanent magnets if the stator of a generator. is a permanent magnet, then when the rotor rotates in this magnetic field environment, it generates an electric current.

So, if the owner wants to retrofit a wind turbine with an electric fan, he must directly replace the motor with a generator. The wind then blows across the fan blades to drive the generator and produce electricity. It is still difficult to transform an electric motor into a generator.

It's just hand to hand combat, give me points.