Glossary
Yaw (wind turbines)
"Yaw" refers to the rotation of a wind turbine around its vertical axis to ensure it is optimally facing the wind for maximum energy generation. This action is critical for the operational efficiency of wind turbines, allowing them to extract wind energy more effectively and safety by adjusting the direction of the turbine according to wind direction changes.
The phenomenon of yawing becomes particularly prominent in the context of horizontal-axis wind turbines, which have a main rotor shaft positioned horizontally to the ground. In horizontal-axis wind turbines, a yaw control system is in place to ensure the alignment of the wind turbine with the oncoming wind. The adjustment may be performed either actively, using powered motors called yaw drives or passively, utilizing the wind force.
The active yaw control system deploys a wind vane fitted to the nacelle of the wind turbine. The wind vane measures the wind direction, and the information gathered informs the yaw drive system in the nacelle to rotate the wind turbine, aligning it with the wind direction. This technique allows for precision and effectiveness in energy generation efficiency by the turbines.
On the other hand, passive yaw control systems, found mostly in smaller wind turbines, use the wind itself to direct the alignment. These turbines have an off-center weight in their nacelle. When the wind changes direction, the force of the wind pushes the nacelle to swing around the tower, reorienting the blades towards the wind.
In understanding yaw, it is equally important to highlight the significance of yaw error, which happens when the nacelle position does not perfectly correspond with the wind direction. The presence of yaw error reduces the efficiency of the wind turbine since the rotor will not face the wind perfectly. This misalignment leads to power losses and increased mechanical stresses on the components. Therefore, a finely tuned and high-performance yaw control system is essential for the optimal operation of wind turbines, significantly impacting the renewable energy generation sector.