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

I see a lot of answers talking about the efficiency, but 4 blades are actually more efficient aerodynamically. 3 blades are used due to econimical reasons as well, as the blades are the most expensive part of a wind turbine. When you compare the efficiency, it won’t make sense to add a fourth blade for a bit of efficiency.

It’s true that 3 blades are more stable, but the tower of a turbine could be improved to keep the same stability with an extra blade. Due to econimical reasons this is also not worth it.

Source: I’m a wind turbine engineer

Answer 2

I see a lot of answers talking about the efficiency, but 4 blades are actually more efficient aerodynamically. 3 blades are used due to econimical reasons as well, as the blades are the most expensive part of a wind turbine. When you compare the efficiency, it won’t make sense to add a fourth blade for a bit of efficiency.

It’s true that 3 blades are more stable, but the tower of a turbine could be improved to keep the same stability with an extra blade. Due to econimical reasons this is also not worth it.

Source: I’m a wind turbine engineer