Abstarct: The output power of a wind turbine is determined by two main factors: wind speed and the area swept by the blades. Wind speed is the main factor determining the production power of the wind turbine. The higher the wind speed, the higher the production power of the wind turbine. Increasing the length of wind turbine blades increases its production power. This is because the surface area is increased by the blades, resulting in more energy being absorbed by the wind. In general, the longer the blades, the higher the output power of the wind turbine. However, increasing the length of blades also has limitations. For example, longer blades are heavier and therefore more expensive to manufacture and install. Additionally, longer blades are more vulnerable to stronger winds. The current training is related to horizontal axis wind turbines and especially to the addition of wind turbine blade extender to increase the length of the wind turbine in order to increase the production power of the turbine.There are design methods for designing wind turbine blade profile to generate energy from wind energy. The experimental production of the power curve according to the wind speed is the subject of the present study, which provides the possibility to investigate the effect of the number and aerodynamic profile of the blade and the twisting angle of the blade on the mechanical power curve of wind turbines.Finally, the decision on the length of the wind turbine blades should be made according to the factors influencing the wind in the area, the cost of construction and installation, and the wind resistance. In the study, the effect of increasing the length of wind turbine blade was investigated by extender. A three-phase motor is used to calculate the production torque and create an induced braking force in its rotor core. The used extenders were in the form of corporate belts in two different sizes, and with the increase in the length of the extender, the rotation speed of the turbine decreased, and as a result, its production torque increased.