Vertical-axis wind turbine

The world's tallest vertical-axis wind turbine, in Cap-Chat, Quebec
Vortexis schematic
Vertical axis wind turbine offshore

A vertical-axis wind turbine (VAWT) is a type of wind turbine where the main rotor shaft is set transverse to the wind while the main components are located at the base of the turbine. This arrangement allows the generator and gearbox to be located close to the ground, facilitating service and repair. VAWTs do not need to be pointed into the wind,[1][2] which removes the need for wind-sensing and orientation mechanisms. Major drawbacks for the early designs (Savonius, Darrieus and giromill) included the significant torque ripple during each revolution, and the large bending moments on the blades. Later designs addressed the torque ripple by sweeping the blades helically (Gorlov type).[3] Savonius vertical-axis wind turbines (VAWT) are not widespread, but their simplicity and better performance in disturbed flow-fields, compared to small horizontal-axis wind turbines (HAWT) make them a good alternative for distributed generation devices in an urban environment.[4]

A vertical axis wind turbine has its axis perpendicular to the wind streamlines and vertical to the ground. A more general term that includes this option is a "transverse axis wind turbine" or "cross-flow wind turbine". For example, the original Darrieus patent, US patent 1835018, includes both options.

Drag-type VAWTs such as the Savonius rotor typically operate at lower tip speed ratios than lift-based VAWTs such as Darrieus rotors and cycloturbines.

Computer modelling suggests that wind farms constructed using vertical-axis wind turbines are 15% more efficient than conventional horizontal axis wind turbines as they generate less turbulence.[5][6]

  1. ^ Cite error: The named reference Jha_2010 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Raciti-Englaro-Benini_2011 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Battisti-Brighenti-Castelli_2016 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Longo-Nicastro-Natalini-Schito-Mereu-Parente_2020 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Eurek_2021 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Hansen-Mahak-Tzanakis_2021 was invoked but never defined (see the help page).