The “wind of change”
is blowing here
We can turn the tide with clean energy from offshore facilities
Large layers of mussels lie a good 20 kilometers off the Dutch coast, on the floor of the North Sea. A little further down live large anemones and starfish, as well as numerous species of fish. What makes this unique: the mussels have colonized on the foundation elements of one of the largest offshore wind farms in the world. Hollandse Kust Zuid was commissioned just one year ago and supplies around 1.5 million households with renewable energy.
It’s not uncommon for the foundations of offshore wind turbines to serve as artificial reefs for marine life. Because shipping and fishing are prohibited between the turbines, flora and fauna can spread out here undisturbed. In the construction of the Hollandse Kust Zuid wind farm, however, nature was given an especially great deal of thought right from the start of the planning process. Larger water holes were deliberately created in the foundations so that marine animals could find shelter inside the foundations. Nine artificial reefs were also created for fish, crabs and small animals. And natural boulders and stones of varying sizes were used for the scour protection, where mussels can comfortably build their colonies.
Conserving nature right from the start
Protecting animals and the environment plays an increasingly important role in the construction of offshore wind turbines. Marine animal-friendly foundations are intended to provide nesting sites while their clever design also helps ensure that fish migrations are not impeded. Elsewhere, advanced monitoring systems are designed to record the impact of a plant on the environment in real time, so that countermeasures can be taken when needed. Researchers at the Hollandse Kust Zuid wind farm will also be studying the life around the turbine at regular intervals. And care is also being taken to ensure that construction of the foundations itself does not cause any damage, since quite a lot of noise can be generated when huge monopile foundations weighing several hundreds of tons are driven into the seabed. This noise can be heard for miles underwater and could cause hearing damage to seals and whales. These animals need good hearing for communication, for foraging for food, and for orientation. To protect them, a second pipe is now often laid around the foundation during the pile-driving process to absorb most of the sound waves. Or a large veil of bubbles is created, in which small air bubbles generated under water swallow part of the sound. This bubble curtain was used in the construction of Hollandse Kust Zuid and the Arcadis Ost wind farm off the coast of Rügen.
Steel enables green energy to be generated using the power of the wind
Protecting flora and fauna in the process is only logical – after all, the energy generated from the power of the wind should be “green”. This means it should conserve resources and be renewable as well as environmentally friendly and climate-friendly. Expanding offshore wind energy is therefore especially important to successfully achieving the climate targets and the energy transition. Even the materials used in an offshore plant should therefore be sustainable while also being extremely resilient and durable – after all, the high seas are subject to harsh conditions. There are heavy winds and high, punishing waves. The air is salty. Flotsam washes up time and again. The tides tug at the foundations. If you want to build an offshore wind turbine, steel is therefore the material of choice. This is because steel is both strong and elastic, exceptionally resilient, and can withstand tides, hurricanes, and corrosion. And it is itself renewable, as it can be 100 percent recycled without any loss of quality. Today, an offshore turbine can consist of up to 2,000 tons of steel, depending on the type. Built into the wind turbine and the towers themselves, but for the most part below the surface of the water, in extremely stable foundations that are anchored deep in the seabed. More than 80 wind farms in Europe, in Asia, and in the United States are now based on steel foundations from Dillinger. From Hollandse Kust Zuid to Arcadis Ost and Japan’s first offshore wind farm. Pure innovation meets pure commitment to the environment and climate.