Offshore wind energy – Hope or hype?

Offshore wind could potentially supply between 12 and 16 per cent of the total EU electricity demand by 2030. This equates to more than 25,000 wind turbines, in wind farms covering up to 20,000 square kilometres of the European continental shelf. Other countries worldwide are also exploring offshore renewable energy including the USA, Japan, India and Eastern Africa.

However, any type of energy production will exert some impact on the local and global environment. In reducing the atmospheric impacts from our energy sources, we must avoid replacing one set of significant impacts with another.

Whilst acknowledging that research into the impacts of the offshore renewable industry is still in its infancy, it is widely regarded that the risk for impacts on the marine environment may not be negligible and must be taken seriously.

IUCN fills the gap

IUCN has undertaken a joint project with the multinational energy corporation E.ON and the Swedish International Development Cooperation Agency (SIDA) to improve the environmental performance of offshore renewable energy projects by developing guidance to support best practice biodiversity considerations. It is envisaged that the guidance will also serve to inform the policy and practice of the conservation community and governments. This is especially relevant for developing countries where capacity is lower but renewable energy infrastructure is increasingly promoted.

The guidance provides a synthesis of current knowledge on the potential biodiversity impacts of offshore wind energy on the marine environment. It is based on scientific evidence and experiences from offshore renewable energy development and other relevant sectors. The foundation of the document is a review of more than 1000 reports and documents, at least 400 of which are peer-reviewed articles published in scientific journals, and results are presented in a jargon-free and balanced way. It aims to be user-friendly as well as structured in a way to provide more detail for those that need it and ultimately to encourage improvements in the sustainability of the offshore renewable energy industry. Overall, the guidance promotes the consideration of science-based impact research, suitable for conducting, scoping and evaluating Strategic Environmental Assessments (SEAs) and Environmental Impact Assessments (EIAs), based on international and national standards.

Threats and opportunities

When exploring the impacts of offshore wind energy production, it is important to consider local impacts in the context of broader, global impacts. Climate change is an increasing threat to biodiversity.

Energy generated from wind can achieve substantial avoidance of greenhouse gas emissions and thus combating climate change. In addition, toxic pollutants associated with for example the burning of fossil fuels, or the local environmental impacts of large hydropower developments, could be avoided by developing wind power. These global and local advantages must however be balanced against the specific adverse effects offshore wind power may have on marine life.

The impacts on marine life are mainly:


  • Piling noise/construction activities;
  • Habitat loss for sea ducks and divers;
  • Migration barriers for birds, sea turtles and whales;
  • Bird collisions;
  • Seabed changes;
  • Navigational hazards/oil spills


  • Trawling exclusion;
  • Habitat enhancement

The impacts of offshore wind farms should be considered in combination with the impacts of other users of a marine environment, such as fisheries, aquaculture, shipping, leisure and tourism as well as other offshore energy projects. Through an effective consultation as part of an impact assessment process, potential threats can be identified, and opportunities could be better managed.