Clusters of wind turbines can frequently be spotted from the window of a train or a car, but occasionally one or two of them are not turning. What does this mean?

It might look as though the turbines have just stopped working, and have been left standing still next to their functioning fellow machines.

However, the truth is that wind turbines are nearly always stopped for a good reason. This can be in order to carry out maintenance and repairs, or often because there is too little or too much wind.

In fact, today’s monitoring systems can even predict that a fault may arise before anything happens and slow or stop the turbine, alerting the person in charge of the wind farm.

And as the technology and monitoring systems are optimised, wind turbines can run for longer without encountering any issues. According to Vestas, for example, since their latest monitoring system was installed a few years ago, the average time between inspections has doubled.

For more, see EWEA’s FAQs.