Environmental impact study of an offshore wind farm

Offshore wind farms are revealed as a key technology in the European Union. Installed power is expected to increase from the current 12 GW to 60 GW by 2030. Onshore wind energy (en tierra) is already part of our daily basis; however Environmental Impact Studies of Offshore Wind Farms are still not widespread in Spain. In our country, hardly any offshore wind farms have been developed, with the exception of the 50 MW Elisa Project located in the Canary Islands, stablished by the company Greenalia.

Offshore wind energy is a renewable alternative with strong potential and one that might be here to stay. Therefore, in Ideas Medioambientales, we are investing time in specialising a part of our technicians in marine environmental inventories and Environmental Impact Studies focused on offshore wind farms.

This article summarises recent environmental impacts found associated with offshore wind energy installations. Some of them are already considered for the design, construction and operation phases of onshore wind farms.

Effects on the seabed

Depending on the technology employed, wind farms with fixed foundations may require excavation works and installation of turbine platforms, which could cause disruption of the seabed and uplift of sediments throughout the water column. These could lead to significant effects on benthic communities. In the case of wind farms with floating foundations, these impacts are highly reduced.

Effects on marine waters

An Environmental Impact Study of an Offshore Wind Farm must consider the effects on marine waters. Both during the construction and operation phases of an offshore wind farm, the impacts of potential fuel or oil spills from the vessels and machinery should be taken into account. During the operation phase, occasional contamination can occur due to discharges from the wind turbine associated with malfunction, maintenance and repairing works.

Noise and vibrations in environmental impact studies of offshore wind farms

In the operation phase of an offshore wind farm, due to the large surface in contact with the water, the vibrations of the wind turbine tower may cause significant underwater vibrations and also affect the seabed.

An Environmental Impact Study of an Offshore Wind Farm is approached very differently from Onshore Wind Farms and presents important limiting factors.

Electromagnetic radiation

The presence of power lines on the seabed generates electromagnetic fields that can impact marine fauna species and ship navigation systems.

Alteration of sea currents

Wind turbines installations may cause changes in sea currents due to dragging of materials, act as barriers, etc. Therefore, it is necessary to study the specific implications of the wind farm in the environment by modelling marine currents.

Environmental Impact Studies of Offshore Wind Farms: Impacts on fauna

Although it is a well-known environmental impact associated with onshore wind energy, these impacts deserve a separate chapter and will be addressed in successive posts. We will explain in detail the main impacts and the species potentially affected.

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More information on offshore wind farms

For more information check these two links:

• SEO/BirdLife expone su posicionamiento frente a este tipo de instalaciones:

Energías renovables marinas

• The second, from Foro Eólico Marino (in Spanish) , presents reasons to develop this type of energ Download your Manifesto here.

If you need more information or want to address an Environmental Impact Study of an Offshore Wind Farm, do not hesitate to contact Ideas Medioambientales.