HAWT

HAWT stands for horizontal-axis wind turbine, a wind turbine design in which the rotor axis is horizontal and the blades rotate in a plane that is roughly vertical to the ground. Modern utility-scale HAWTs are usually upwind machines with a three-bladed rotor mounted on top of a tall nacelle and tower. Downwind configurations exist but are less common.

A typical HAWT consists of blades attached to a hub, a nacelle housing the gearbox and electric generator, a drive train, a yaw system, and blade pitch actuators. The nacelle is mounted on a tall tower and connected to foundations. Power electronics in the system condition and feed electricity to the grid.

Operation involves wind lifting the blades to produce torque that drives the rotor. The drivetrain increases shaft speed for the generator, which converts mechanical energy to electrical energy. The control system regulates rotor speed, power, and loads through blade pitch and yaw adjustments, and it can brake blades or halt the turbine at high winds or during maintenance.

History and context: Modern HAWTs evolved during the 20th century, with rapid growth after the 1980s as commercial wind energy expanded. They are now the dominant form of utility-scale wind turbines worldwide, produced by many manufacturers. Advantages include high energy capture at scale and straightforward maintenance access, while challenges include noise, visual impact, bird interactions, and dependency on favorable wind conditions. They are contrasted with vertical-axis wind turbines, which have different aerodynamics and installation considerations.