A construction site is opening up in the North Sea that is so large that the horizon simply swallows it up.

If you looked through binoculars at the silhouettes of the most distant structures, you would see them shrink behind the curvature of the earth.

Anna Lena Niemann

Editor in the “Technology and Engine” department.

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When this area sheds its status as a construction site, most likely this year, Hollandse Kust Zuid will lead the ranks of the largest offshore wind farms in the world.

140 turbines in the 11-megawatt class then face the North Sea wind.

There has never been a park with a rated output of 1.5 gigawatts.

The logistical and technical effort is huge.

The installation ships equipped with cranes, which push themselves between the turbines and converter platforms on steel stilts out of the water of the Dutch North Sea, are in a class of their own.

Everything here deserves the attribute: gigantic.

For households and industry, which will soon be able to obtain cheap green electricity from the sea, and also from the first offshore wind farm, which does not collect a cent in subsidies for the electricity produced, this gigantism is a win.

But what is the verdict for another group that is sometimes battered anyway?

How do sea dwellers cope when their habitat first becomes a construction site and later becomes a maritime industrial park because new technical structures are moving in?

When operator Vattenfall and BASF as a major investor drove journalists through the 225 square kilometers of Hollandse Kust Zuid last year, work on the foundations was already complete.

All 140 of the yellow stumps are where they should be, although some are still missing the tower, nacelles and rotor blades.

For Sytske van den Akker this means that the most delicate part of their work is done.

The marine biologist works in Vattenfall's in-house environmental consultancy and is responsible for implementing environmental regulations.

Protecting marine mammals from the noise of pile driving plays a major role.

Offshore turbines can be based on different foundations, which mostly consist of one, three or four steel girders - monopile, tripod or jacket.

Only with a lot of noise do they find a firm footing.

Technology can protect marine mammals from noise

The Dutch wind farm is dealing with up to 700 tons per monopile.

A hydraulic hammer rammed it deep into the seabed with well-aimed blows.

The sound pressure that arises under water is a problem for harbor seals and seals, for fish, and above all for the shy porpoises, which need their sensitive hearing to find their way around and to hunt.

The number of protected animals in the North Sea has only just recovered tentatively.

The boom in offshore wind power, which is announced in Europe and worldwide, should not endanger this, even if the greatest risk for the animals still comes from the gillnets used by fisheries.

However, marine biologist van den Akker has the technology to protect the animals.

"We worked with bubble curtains," she says, "that massively reduces the noise of the piling work." Setting bubble curtains is now a common method that is also used in wind farms in Germany's exclusive economic zone.