A lake in the sea

The Dutch have always had a special relationship with the sea. Forced to protect their lands from the onslaught of water, some time ago they went back on the offensive, wresting parcels of farmland – the famous polders – from the sea. Now, at a time of great energy procurement difficulties and enormous environmental challenges, they are looking to the sea once again.

The Dutch energy consulting company Kema is currently studying a plan, worth about € 3 billion, to build an artificial hydroelectric energy island. The plan is to build an island about 30 kilometres off Holland’s coastline on a 20-metre seabed, in the centre of which a lake 40 metres below sea level will be dug. Water will flow into this subsurface lake as it does in some dikes on land, powering generators, and will be pumped back into the sea in the event of surplus.

This 1,500 MW hydroelectric plant will be a “security reserve” if the wind turbines were to stop due to lack of wind, and will also provide electricity in cases of peak demand – a giant step forward towards the CO2 emissions reduction required by the EU for 2020.