2 BLADED AND 3 BLADED WIND TURBINES

Today's "modern" 3-bladed wind turbines represent the latest technological improvements in wind turbine generators, and are superior to the 20-30 year old technology that 2-bladed wind turbines represent.
First of all, it is important to remember that 2-bladed wind turbines may generate only about 90% of the power of a 3-bladed wind turbine of comparable size. While a 2-bladed wind turbine saves the weight of one extra blade when compared with a 3-bladed wind turbine, engineers of the most efficient wind turbines have determined that the extra blade used on 3 bladed wind turbines provide the optimum wind turbine efficiency and wind turbine design for the "ideal" wind turbine generators of today.
Secondly, the top-3 leading wind turbine manufacturers have standardized on the 3-bladed wind turbine. They do not manufacture any 2-bladed wind turbines. Plainly stated, a wind turbine with an even number of blades (2 blades or 4 blades) are NOT of optimum design or efficiency. In fact, this debate was settled years ago when the wind turbine engineers and designers began building wind turbines over 600 kW in power output.
The top-3 leading wind turbine manufacturers have standardized on the 3-bladed wind turbine. They do not manufacture any 2-bladed wind turbines. Plainly stated, a wind turbine with an even number of blades (2 blades or 4 blades) are NOT of optimum design or efficiency. In fact, this debate was settled years ago when the wind turbine engineers and designers began building wind turbines over 600 kW in power output.
The leading wind turbine manufacturers and their engineers have decided that 3 bladed wind turbines are the optimum number of wind turbine blades due to the stability of the wind turbine as well as the significant wind loads and stresses placed on a 2-bladed wind turbine. A wind turbine that has an odd number of blades is similar to a disc when calculating the computational fluid dynamics of the wind turbine. Engineers have learned that wind turbines that have an even number of blades - such as the 2 bladed wind turbines of the past - have stability problems for a machine with a stiff structure. The reason for this problem is simple, engineers recognized that when a 2-bladed wind turbine's top blade bends backwards - when the wind turbine's 2 blades are in the vertical position - since it is now generating the maximum power from the wind - that the lower or bottom blade is now aligned with the tower and the blade is hidden or blocked from the wind - and this generates a huge amount of stress and loads on the wind turbine and its' primary components such as the bearings, shaft, transmission etc.