Storm Ciarán is blowing fiercely through our region: what does this mean for our Belgian offshore wind farms?


The winter months traditionally provide the best production figures. Due to the higher wind speeds and the absence of windless days, the wind turbines run at a higher capacity on average.

The Royal Meteorological Institute (RMI) predicted that wind gusts of 120 to 150 kilometres per hour may occur on the high seas on Thursday.

The Belgian offshore wind farms produce electricity more than 90% of the time: the wind turbines produce from a light breeze (2 Beaufort) to a heavy storm (11 Beaufort). More than 40% of wind turbines can continue to produce during heavy storms.

As the wind blows harder at sea, an offshore wind turbine is designed to produce electricity at very high speeds (up to 110 km/h). If higher wind speeds are detected, the turbine automatically switches to safety mode.

In concrete terms, this means that the turbine switches to the ‘feathered position’: the blades position themselves differently depending on the wind, which reduces the impact on the turbine and the foundations. The ‘feathered position’ can also be activated at lower wind speeds. The blades are therefore not clamped in a fixed position, but continue to rotate freely in a protective position. Above the maximum speed (cut-off speed), no electricity is supplied to the grid to protect the rotor.

The eight Belgian wind farms together can produce 2262 MW. Offshore wind energy accounts for 10% of total electricity consumption in Belgium. On the morning of November 2 at 8:45 am, the wind turbines were running at 97% capacity. At noon, the maximum wind speed was exceeded and production had to be temporarily reduced. As soon as the wind speeds decreased, the wind turbines automatically restarted as planned.

Last year during the passage of storm Eunice, it was the first time in Belgian offshore wind history that all wind turbines collectively went into safety mode.

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