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Environmental Effects of Renewable Energy from the Sea
As industry, academia, and government seek to develop new renewable energy sources from tides, waves, and offshore wind, potential environmental effects must be evaluated and measured to ensure that aquatic and avian animals, habitats, and ecosystem functions are not adversely affected, nor that important coastal and ocean uses are displaced.
Tethys is a knowledge management system that gathers, organizes, and provides access to information on the environmental effects of marine and hydrokinetic (MHK) and offshore wind development. This information is made available by collaboration at local, national, and international levels. Tethys, named after the mythical Greek titaness of the seas, supports programs at the U.S. Department of Energy's Wind and Water Power Technologies Office.
Tethys also supports a growing community of MHK and offshore wind researchers, regulators, and developers through outreach and communication channels including the Tethys blog, links to pertinent research institutions, other databases with similar missions, and broadcasts of presentations, webinars, seminars, and symposia relating to the environmental effects of marine energy and offshore wind. As the Tethys community expands and more users create accounts, each user’s personal interests and areas of expertise may be catalogued upon request to facilitate more communication amongst Tethys community members.
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Marine and Hydrokinetic (MHK) or marine energy development in U.S. and international waters includes projects using the following devices:
- Wave energy converters in open coastal areas with significant waves;
- Tidal turbines placed in coastal and estuarine areas;
- In-stream turbines in fast-moving rivers;
- Ocean current turbines in areas of strong marine currents;
- Ocean Thermal Energy Converters in deep tropical waters.
Common environmental concerns associated with marine energy developments include:
- The risk of marine mammals and fish being struck by tidal turbine blades;
- The effects of EMF and underwater noise emitted from operating marine energy devices;
- The physical presence of marine energy projects and their potential to alter the behavior of marine mammals, fish, and seabirds with attraction or avoidance;
- The potential effect on nearfield and farfield marine environment and processes such as sediment transport and water quality.
Tethys is also a clearinghouse for information and metadata associated with the Annex IV project, an international collaborative project among member nations of the International Energy Association’s Ocean Energy Systems (OES). The goal of Annex IV is to examine the environmental effects of marine energy devices and environmental research studies from around the world and disseminate information to marine energy researchers, regulators, developers, and stakeholders.
Led by the U.S. Department of Energy, the Annex IV project concluded its first phase in 2013 with a Final Annex IV Report that uses the best available science and information to examine three case studies of specific interactions of marine energy devices with the marine environment. The Annex IV project has also developed a widespread community of international experts focused on aggregating and disseminating information related to the potential environmental effects of marine energy developments.
For more information on Annex IV, please visit the About Annex IV page.
Significant generation of offshore wind energy already contributes to electricity needs in Europe and Asia and now the first offshore wind farms are under development in U.S. waters. While the offshore wind industry has grown dramatically over the last several decades, especially in Europe, there is still a great deal of uncertainty associated with how the construction and operation of these wind farms affect marine animals and the marine environment.
Traditional offshore wind turbines are attached to the seabed in shallower waters within the nearshore marine environment. As offshore wind technologies become more advanced, floating structures have begun to be used in deeper waters where more wind resources exist.
Common environmental concerns associated with offshore wind developments are:
- The risk of seabirds being struck by wind turbine blades or being displaced from critical habitats;
- The underwater noise associated with the installation process of monopile turbines;
- The physical presence of offshore wind farms altering the behavior of marine mammals, fish, and seabirds with attraction or avoidance;
- The potential disruption of the nearfield and farfield marine environment from large offshore wind projects.
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