Capturing energy from waves with a point absorber buoy, surface attenuator, oscillating water column, or overtopping device.

Solar energy from the sun creates temperature differentials that result in wind. The interaction between wind and the surface of water creates waves, which are larger when there is a greater distance for them to build up. Wave energy potential is greatest between 30° and 60° latitude in both hemispheres on the west coast because of the global direction of wind. When evaluating wave energy as a technology type, it is important to distinguish between the four most common approaches: point absorber buoys, surface attenuators, oscillating water columns, overtopping devices, and oscillating wave surge converters.

Point Absorber Buoy

This device floats on the surface of the water, held in place by cables connected to the seabed. Buoys use the rise and fall of swells to drive hydraulic pumps and generate electricity. EMF generated by electrical transmission cables and acoustic of these devices may be a concern for marine organisms. The presence of the buoys may affect fish, marine mammals, and birds as potential minor collision risk and roosting sites. Potential also exists for entanglement in mooring lines. Energy removed from the waves may also affect the shoreline, resulting in a recommendation that sites remain a considerable distance from the shore.

Surface Attenuator

These devices act similarly to point absorber buoys, with multiple floating segments connected to one another and are oriented perpendicular to incoming waves. A flexing motion is created by swells that drive hydraulic pumps to generate electricity. Environmental effects are similar to those of point absorber buoys, with an additional concern that organisms could be pinched in the joints.

Oscillating Water Column

Oscillating water column devices can be located on shore or in deeper waters offshore. With an air chamber integrated into the device, swells compress air in the chambers forcing air through an air turbine to create electricity. Significant noise is produced as air is pushed through the turbines, potentially affecting birds and other marine organisms within the vicinity of the device. There is also concern about marine organisms getting trapped or entangled within the air chambers.

Overtopping Device

Overtopping devices are long structures that use wave velocity to fill a reservoir to a greater water level than the surrounding ocean. The potential energy in the reservoir height is then captured with low-head turbines. Devices can be either on shore or floating offshore. Floating devices will have environmental concerns about the mooring system affecting benthic organisms, organisms becoming entangled, or EMF effects produced from subsea cables. There is also some concern regarding low levels of turbine noise and wave energy removal affecting the nearfield habitat.

Oscillating Wave Surge Converter

These devices typically have one end fixed to a structure or the seabed while the other end is free to move. Energy is collected from the relative motion of the body compared to the fixed point. Oscillating wave surge converters often come in the form of floats, flaps, or membranes. Environmental concerns include minor risk of collision, artificial reefing near the fixed point, EMF effects from subsea cables, and energy removal effecting sediment transport.

Title Author Date Type of Content Technology Type Stressor Receptor
Appropriate Assessment Screening for AMETS, Co. Mayo Scally L. January 2011 Research Study Annex IV MHK, Wave Dynamic Device, Static Device Birds
Environmental Effects and the Permitting Processes for a Deep Water Offshore Wind-Wave Hybrid Generator DeVault, G. March 2011 Report Wave, Offshore Wind
First Interim Report of the Working Group on Marine Renewable Energy (WGMRE) ICES April 2014 Report Wave, Tidal Ecosystem
Animals Interacting with Wave and Tidal Devices Wave, Tidal
Will Ocean Energy Harm Marine Ecosystems? Hammar L. January 2013 Research Study Annex IV Wave, Ocean Current, Tidal Dynamic Device, EMF, Energy Removal, Noise, Static Device Birds, Farfield Environment, Fish, Invertebrates, Marine Mammals, Nearfield Habitat, Sea Turtles
Power from the Brave New Ocean - Marine Renewable Energy and Ecological Risks Hammar L. February 2009 Research Study Annex IV Wave, Ocean Current, Tidal Dynamic Device, EMF, Energy Removal, Noise, Static Device Birds, Farfield Environment, Fish, Invertebrates, Marine Mammals, Nearfield Habitat, Sea Turtles
Acoustic Environmental Monitoring - Wello Penguin Cooling System Noise Study Beharie, R., Side, J. January 2012 Report Wave Noise
Wello Penguin at EMEC Wello Oy January 2011 Project Site Annex IV Wave
Environmental Impact Assessments for Wave Energy Developments – Learning from Existing Activities and Informing Future Research Priorities Leeney, R., Greaves, D., Conley, D., O'Hagan, A. June 2014 Journal Article Wave
Marine Renewable Energy Technology and Environmental Interactions Shields, M., Payne, A. January 2014 Book Wave, Tidal, Offshore Wind EMF, Energy Removal, Noise, Static Device Birds, Invertebrates, Marine Mammals, Sea Turtles
A Marine Spatial Planning Approach to Select Suitable Areas for Installing Wave Energy Converters on the Basque Continental Shelf (Bay of Biscay) Galparsoro, I., Liria, P., Legorburu, I., Bald, J., Chust, G., Ruiz-Minguela, P., Pérez, G., Marqués, J., Torre-Enciso, Y., Gonzalez, M., Borja, A. December 2011 Journal Article Wave Static Device Socio-economics
Irish Maritime and Energy Resource Cluster (IMERC) University College Cork, Cork Institute of Technology, Irish Naval Service March 2010 Website Wave, Tidal
Underwater Active Acoustic Monitoring Network For Marine And Hydrokinetic Energy Projects Stein, P., Edson, P. December 2013 Report Wave, Tidal Dynamic Device, Noise, Static Device Fish, Marine Mammals
Interactions of Marine and Avian Animals Around Marine Energy Devices in Scotland Wave, Tidal
Environmental Risk Evaluation System An Approach to Ranking Risk of Ocean Energy Development on Coastal and Estuarine Environments Copping, A., Hanna, L., Van Cleve, B., Blake, K., Anderson, R. April 2014 Journal Article Wave, Tidal, Offshore Wind Chemical Leaching, Dynamic Device, Energy Removal Birds, Fish, Marine Mammals
An International Assessment of the Environmental Effects of Marine Energy Development Copping, A., Battey, H., Brown-Saracino, J., Massaua, M., Smith, C. April 2014 Journal Article Wave, Tidal Dynamic Device, Energy Removal, Noise Fish, Marine Mammals
Wave Farm Modelling of Oscillating Wave Surge Converters Sarkar, D., Renzi, E., Dias, F. July 2014 Journal Article Wave Energy Removal
Wave Power Extraction from a Bottom-Mounted Oscillating Water Column Converter with a V-Shaped Channel Deng, Z., Huang, Z., Law, A. July 2014 Journal Article Wave Energy Removal
Reedsport OPT Wave Park Plans Terminated MHK, Wave
Wave Farm Impact The Role of Farm to Coast Distance Iglesias, G., Carballo, R. September 2014 Journal Article Wave Energy Removal Farfield Environment
A Wave Farm for an Island Detailed Effects on the Nearshore Wave Climate Veigas, M., Ramos, V., Iglesias, G. April 2014 Journal Article Wave Energy Removal Nearfield Habitat
Physical Modelling of Wave Energy Converters Sheng, W., Alcorn, R., Lewis, T. July 2014 Journal Article Wave
Assessment of the Changes Induced by a Wave Energy Farm in the Nearshore Wave Conditions Bento, A., Rusu, E., Martinho, P., Soares, C. March 2014 Journal Article Wave Energy Removal Nearfield Habitat
A Remotely Operated Autonomous Wave Energy Converter System Lewis, T. March 2014 Thesis Wave
Farr Point Wave Array – Phase 1 Pelamis Wave Power Project Site Annex IV Wave
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