Why do windmills typically have 4 blades, yet all modern wind turbines have 3?

Question

Why do windmills typically have 4 blades, yet all modern wind turbines have 3?

In: 9124

Answer 1

Vibrational balance (prevention of self destruction in high winds) is easier to build with 4 blades exactly 90 degrees apart. However, with modern design and construction methods, it costs far less to build, transport, and maintain with only 3 blades. Each of the 3 can also be larger in surface area to compensate for the “loss” of that 4th blade.

Answer 2

Vibrational balance (prevention of self destruction in high winds) is easier to build with 4 blades exactly 90 degrees apart. However, with modern design and construction methods, it costs far less to build, transport, and maintain with only 3 blades. Each of the 3 can also be larger in surface area to compensate for the “loss” of that 4th blade.