At what wind speed does a wind turbine shut down?

The classic cut-out speed is around 25 m/s. At this speed the rotor blades are pitched out of the wind, the generator is disconnected from the grid and the turbine stands still until the wind drops back below a safe value.

What is storm control?

Modern turbines replace the abrupt storm shutdown with a gradual reduction of rotor speed and power: the rotor blades are progressively turned out of the wind, the turbine keeps running but produces electricity at lower rotor speed and power. Manufacturers such as Enercon or Siemens have implemented this.

Guide · Technology

What Do Wind Turbines Do in a Storm?

In short: Classically, a wind turbine shuts down at around 25 m/s wind speed (cut-out). Modern turbines use storm control: instead of shutting down abruptly, they progressively pitch the rotor blades out of the wind and keep producing electricity at reduced rotor speed and power. Sources: Windmesse, BWE.

The classic storm shutdown (cut-out)

From around 25 m/s mean wind speed (≈ 90 km/h, Beaufort 10) the turbine reaches its design limit.
The pitch control turns the rotor blades out of the wind, the rotor slows down and stops.
The generator is disconnected from the grid, the mechanical brake secures the rotor.
The turbine stands still until the wind drops below ~22 m/s for a certain period (hysteresis prevents constant on/off cycling).

Modern storm control

Instead of an abrupt standstill, modern turbines ramp power down gently from around 22–25 m/s — the pitch control turns the blades gradually, the rotor speed drops, the generator keeps delivering, but at lower power. Advantages:

More yield in storm conditions (instead of 0 kW).
Gentler load changes on the turbine — less material stress.
Grid stability during a storm front, because the feed-in does not drop away all at once.

This control approach is state of the art today on large onshore and offshore turbines from leading manufacturers.

What happens mechanically

Pitch control: each rotor blade can be turned independently about its longitudinal axis (pitch angle) to "shed" or "catch" the wind.
Yaw drive: the entire nacelle can rotate about the tower axis to align the rotor optimally into the wind — or deliberately turn it out of the wind.
Structural reserves: turbines are designed to IEC classes for defined extreme winds (e.g. Class I for ≥ 50 m/s peak gust).

Nothing wild happens in a storm: The turbine either stands still in a controlled way or keeps producing at reduced power. Structural failure is extremely rare and usually traced to design defects or neglected maintenance — with modern turbines and proper maintenance, it is exceptionally unlikely.

Frequently asked questions

What if the storm overwhelms the turbine anyway?

Turbines are designed for the 50-year wind events of their IEC class — see Turbine Classes. Realistically, a turbine in the highest classes is exposed to extreme winds several times over its lifetime without taking damage.

Can individual turbines be damaged by lightning?

Yes, lightning strikes are more common than storm damage. Turbines therefore have integrated lightning protection concepts (receptors at the blade tip, earthing). Repairs of individual rotor blades are standard.

What happens during a power grid outage in a storm?

If the grid is lost, modern turbines can use the pitch control to bring themselves safely to a standstill — the backup energy for the pitch drive comes from buffer batteries in the nacelle.

Wind turbine in a storm – shutdown vs. storm control, power curve and mechanisms