You have probably experienced how hailstorms or thunderstorms in particular, are associated with frequent gusts of wind which both change speed and direction.

In areas with a very uneven terrain surface, and behind obstacles such as buildings there is similarly created a lot of turbulence, with very irregular wind flows, often in whirls or vortexes in the neighbourhood.

You can see an example of how turbulence increases the fluctuations in the wind speed in the image, which you may compare with the image on the previous page.

Turbulence decreases the possibility of using the energy in the wind effectively for a wind turbine. It also imposes more tear and wear on the wind turbine, as explained in the section on fatigue loads. Towers for wind turbines are usually made tall enough to avoid turbulence from the wind close to ground level.