Then another question arises that why can’t we use a wind turbine with only 2 blades? Each blade of a wind turbine helps the following blade in rotation by disturbing the air so you want to keep a minimum number of blades. Although two blades are the minimum requirement to balance the turbine and harvest maximum energy, it has its own negative effects.
A two blade wind turbine can match the power output of a three blade wind turbine if we increase the length of the blades by 50% which ultimately increases the cost of the turbine. Moreover, it will also increase the height of the mast for providing more ground clearance.
We can also increase the rotational speed of the two blade wind turbine by 22.5% to match the efficiency of a three blade wind turbine. This will spin the blades faster but it is entirely difficult. Rotating blades of a wind turbine make noise. So, when the blades of two-blade wind turbine rotate faster, they make more noise. We know that people don’t like living in a noisy neighborhood. So, we can’t increase the speed of the blades as it will be very disturbing for the people living in the surrounding area.