A spokeswoman for Belgium's North Sea Minister, Johan Vande Lanotte, has revealed plans to build an artificial island in the North Sea to store wind energy.

The plan is to build a donut-shaped island out of sand 3 kilometres off the Belgian coast near the town of Wenduine.

Belgium is aiming to generate 2,300 megawatts of electricity from a network of wind farms in the North Sea. Water would be pumped out of the centre of the island when there was excess energy from the wind farms and let back in through turbines when the wind energy was insufficient.

The island, which is expected to take at least five years to plan and build, would also house an electricity substation.