Energy islands taking flora, fauna and bats into consideration

Before building energy islands and associated offshore wind farms in the North Sea or the Baltic Sea, Energinet must ensure that the impact on the existing environment in the areas will be as small as possible. Energinet is therefore already conducting preliminary studies of flora, fauna, the seabed and many other factors in the designated areas.

“We have made an early start, because we are being very thorough – to ensure that the energy island projects can be implemented with the greatest possible consideration of nature and the environment and minimum impact,” says Kirsten Qvist Isak, Energinet’s subproject manager in the preliminary study area.

Energinet is collecting information from the preliminary studies which will form the basis for the future work of designing and constructing energy islands, offshore wind farms and the intervening infrastructure.


Nature and the environment must be mapped

The natural and environmental factors to be studied at sea have been jointly defined by Energinet and the Danish Energy Agency.

“One element we have to study is the species on the seabed – benthic fauna and flora. This involves taking underwater photos and samples in several locations, and inspecting the sand for animals and plants. The marine mammal population also has to be studied. Since porpoises communicate via clicking sounds, they can be counted using sound recordings from a buoy on the sea,” says Kirsten Qvist Isak.

Bats and seasonal populations

In addition to the familiar animals and plants found at sea (the benthic fauna and flora, marine mammals, birds, fish, etc.), the studies also encompass bats. Bats live in old trees and buildings, but previous experience from offshore projects has found that bats fly far offshore to find food, and can therefore be found in proximity to offshore wind farms.

In addition to bats, many sea creatures cover large distances in the course of a year. They can use a specific area to breed or spend the winter, or to migrate through when the seasons change. The preliminary studies will therefore run for a long time over the coming years, notes Kirsten Qvist Isak:

“It’s important that we study and map the seasonal changes in the area. This mapping will be vital in the planning, so that consideration is given to species at vulnerable times in their annual cycle, and the impact thereby minimised.”

The tender documents for the preliminary studies have been distributed, and Energinet expects that a consultant company will be selected over the summer. The selected consultant company will then start the preliminary studies in autumn, and these will run for 1-2 years. The end result will be a strategic environmental assessment of the plan for the energy islands. The work will also form the basis for the subsequent environmental assessment to be prepared for the specific project covering the energy islands and offshore wind farms.


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  • The environment and nature studies are expected to start in autumn 2021.
  • Factors will be investigated separately for the North Sea and the Baltic Sea, as the conditions are different.
  • The geophysical conditions in the North Sea are currently being mapped. The seabed and soil layers are being examined, with the aim of describing how foundations for wind turbines and the like can be established with minimal environmental impact.