A component of the wind turbine (equipment responsible for converting the wind’s kinetic energy into mechanical energy, which will later be transformed into electrical energy), the wind turbine rotor is composed of blades, the wind turbine hub, and pitch control mechanisms.
Types of Wind Turbine Rotors
The wind turbine rotor can have a vertical or horizontal axis. In the first type, wind energy is harnessed without needing to change the rotor’s position—since it does not rotate following the wind’s direction. This model of wind turbine rotor is suitable for urban spaces, although it performs less efficiently than the horizontal axis rotor.
Vertical Axis Rotors
There are two types of vertical wind turbine rotors. The Savonius Rotor is driven by the drag force of the air (a force that resists the movement of a solid body through a gaseous or liquid fluid—in this case, the wind), and its efficiency is higher in low winds. The Darrieus Rotor, on the other hand, consists of vertical blades that move with the wind’s action, being more advantageous than the first option.
Horizontal Axis Rotors
The horizontal wind turbine rotor, in turn, operates similarly to windmills, with an aerodynamic profile, containing one to three blades or more (multi-blade). Models with three turbines are considered the most efficient, with good cost-effectiveness.
This model of wind turbine rotor needs to be installed in higher locations and have a long length—with 100 meters in height or more, capable of generating up to 5 megawatts of energy. The peak energy generation of a horizontal wind turbine rotor is caused by strong winds, with efficiency exceeding 45%. In low winds, it has an average efficiency of 30%.
Horizontal wind turbine rotors are divided into two categories: upwind, with rigid blades and a motorized device that orients the rotor according to the wind direction; and downwind, where the wind blows from the rear of the blades and the rotor is flexible and automatically orients itself.
