Some 80% of wind turbines in the Netherlands were operational on Wednesday afternoon at the height of the storm when electricity prices dropped to below €20 per megawatt/hour, the Financieele Dagblad reported on Thursday.

Wind energy expert Duco van Dijk told the paper turbines accounted for 25% of total production in the country on Wednesday.  Turbines are extremely expensive to build, but once in place, power is virtually free, he said: ‘Wind costs nothing.’

Because they have the highest variable costs, gas-fired electricity plants are idled during periods of heavy winds.

Electricity prices are far lower in neighbouring Germany which has more wind energy capacity and often exports its surplus to the Netherlands, Frank van Os of electricity broker Powerhouse said.

‘That puts pressure on power prices here, but the winds are lighter now and electricity prices are rising,’ he said. Wind energy capacity is now too meagre to effect overall electricity prices, but this is due to change when additional offshore wind farms come on stream, he said.