Tidal

Capturing tidal fluctuations with turbines, reciprocating devices, kites, screws, barrages, or lagoons.

Gravity from the moon and sun cause water in the ocean to bulge in a cyclical pattern as the Earth rotates, causing water to rise and fall relative to the land in what are known as tides. Land constrictions such as straits or inlets can create high velocities at specific sites, which can be captured with the use of devices such as turbines. Since seawater is about 800 times denser than air, tidal turbines can collect energy with slower water currents and smaller turbines than wind energy. While tidal currents are very predictable, challenges arise due to the need for devices to collect flow from opposite directions and survive the harsh corrosive marine environment.

 

Environmental effects will vary between the seven most common approaches: axial flow turbine, cross flow turbine, reciprocating device, tidal kite, Archimedes screw, tidal lagoon, and tidal barrage.

 

Axial Flow Turbine

 

These turbines are the most similar to traditional windmills, where the kinetic energy of moving water is captured by spinning blades facing the direction of flow. Turbines can be open or ducted (shrouded) and placed anywhere in the water column, though bottom-mounted is the most common.

 

The main environmental concern is collision between turbine blades and marine organisms due to natural animal movements, attraction to the device, or inability to avoid the turbines within strong currents. It should be noted that these turbines spin much slower than propellers on ships. There is also concern that noise from turbines can affect animals that use sound for communication, social interaction, orientation, predation, and evasion. As with all electricity generation, there is a slight concern that electromagnetic fields generated by power cables and moving parts may affect animals that use Earth's natural magnetic field for orientation, navigation, and hunting. Likewise, chemicals such as anti-corrosion paint and small amounts of oil and grease may enter the waterbody during spills, though some turbine designs do not require lubrication. Large-scale tidal energy removal (from arrays) may disrupt natural physical systems to cause degradation in water quality or changes in sediment transport, potentially affecting the ecosystem.

Cross Flow Turbine

 

These turbines are generally cylindrical on a horizontal axis, where kinetic energy of moving water is captured by spinning blades oriented transversely to the direction of flow. Turbines can be open or ducted (shrouded) and placed anywhere in the water column, though bottom-mounted is the most common.

 

There is typically less environmental concern for collision between turbine blades and marine organisms because blades are spinning in the same direction to the flow of water, depending on the design. Concerns about noise, electromagnetic fields, chemicals, and energy removal are similar to that of axial flow turbines.

Reciprocating Device

 

Reciprocating devices do not have rotating components, but instead have a hydrofoil that is pushed back and forth transverse to the flow direction by lift or drag. Oscillating devices are the most common form of reciprocating devices.

 

Reciprocating devices often move slower than turbines, but move more freely in the water, resulting in some concern for collision. Reciprocating devices often produce little noise, though this depends on the design and generator. Concerns about electromagnetic fields, chemicals, and energy removal are similar to that of other tidal devices.

Tidal Kite

 

A tidal kite is comprised of a hydrodynamic wing, with a turbine attached, tethered by a cable to a fixed point that leverages water flow to lift the wing. As the kite 'flies' loops through the water, the speed increases around the turbine, allowing more energy extraction for slower currents. The kite is neutrally buoyant so as not to fall as the tide changes direction.

 

Collision risk may be of some concern with tidal kites. Although animals are more likely to collide with the tether than the kite itself, little is known about the ability of animals to detect the free movement of some tidal kites. Tidal kites emit noise over a larger frequency than horizontal axis turbines, though this depends on the design and generator. Concerns about electromagnetic fields, chemicals, and energy removal are similar to that of other tidal devices.

Archimedes Screw

 

Historically designed to efficiently transfer water up a tube, an Archimedes screw is a helical surface surrounding a ventral cylindrical shaft. Energy is generated as water flow moves up the spiral and rotates the device.

 

The helical turbine moves very slowly relative to other tidal technologies, and is likely to have little collision risk. Archimedes screws often produce little noise, though this depends on the design and generator. Concerns about electromagnetic fields, chemicals, and energy removal are similar to that of other tidal devices.

Tidal Lagoon

 

Tidal lagoons are comprised of retaining walls embedded with reversible low-head turbines that surround a large reservoir. Tides cause a difference in the water height inside and outside of the walls, functioning very similar to a low-head conventional hydrokinetic dam that works in both direction.

 

The ecosystem within the reservoir undergoes significant transformation, potentially yielding positive impacts with a more diverse seabed, depending on site selection. The changes to the physical system are similar to conventional marine engineering projects and can include altering water flow and shoreline processes partially due to energy removal. Decreased flushing of the reservoir may cause some problems for water quality. There are some collision concerns that arise if fish and benthic invertebrates try to traverse the retaining wall through turbines. Impacts from noise depend on turbine selection. There is little concern for electromagnetic fields because cables are embedded in the retaining wall and are not openly exposed to water. The new reservoir may also create calmer waters that allow better recreation.

Tidal Barrage

 

Tidal barrages are dams built across the entrance to a bay or estuary that captures potential tidal energy, similar to tidal lagoons. Energy is collected when the height difference on either side of the dam is greatest, at low or high tide. A minimum height fluctuation of 5 meters (16.4 feet) is required to justify the construction, so only 40 locations worldwide have been identified as feasible.

 

Installing a tidal barrage impacts bay or estuary ecosystems due to the alteration of tidal flows and can have negative effects such as changing the shoreline and important tidal flats. Inhibiting the flow of water in and out of the bay, may also lead to less flushing of the bay or estuary, altering the water quality, and potentially causing additional turbidity (suspended solids) and less saltwater, which may result in the death of fish that act as a vital food source to birds and mammals. Migrating fish may also be unable to access breeding streams, and may attempt to pass through the turbines and risk collision. Impacts from noise depend on turbine selection, similar to tidal lagoons. Decreasing shipping accessibility can become a major socio-economic issue, though locks can be added to allow slow passage. However, the barrage may improve the local economy by increasing land access when used as a bridge and allowing for more recreation opportunities due to calmer waters.

Total Results: 669
Titlesort ascending Author Date Type of Content Technology Type Stressor Receptor
Assessing collision risk between underwater turbines and marine wildlife Scottish Natural Heritage May 2016 Report Marine Energy general, Tidal Dynamic Device
Array Optimization for Tidal Energy Extraction in a Tidal Channel - A Numerical Modeling Analysis Yang, Z., Wang, T., Copping, A. April 2014 Conference Paper Marine Energy general, Tidal Energy Removal
Argyll Tidal Demonstrator Project Planned Project Site OES-Environmental Marine Energy general, Tidal
Are Larvae and other Planktonic Organisms at Risk from Tidal Energy Development? Andrea Copping August 2016 Blog Article Tidal
Appropriateness of Existing Monitoring Studies for the Fundy Tidal Energy Project and Considerations for Monitoring Commercial Scale Scenarios Fisheries and Oceans Canada June 2012 Report Marine Energy general, Tidal Farfield Environment, Fish
Applying a simple model for estimating the likelihood of collision of marine mammals with tidal turbines Copping, A., Grear, M. August 2018 Journal Article Marine Energy general, Tidal Dynamic Device Marine Mammals
Application of Tidal Energy for Purification in Fresh Water Lake Jung, R., Isshiki, H. January 2015 Journal Article Marine Energy general, Tidal
Annex IV 2016 State of the Science Report: Environmental Effects of Marine Renewable Energy Development Around the World Copping, A., et al. April 2016 Report Marine Energy general, Tidal, Wave Dynamic Device, EMF, Energy Removal, Noise, Static Device Benthic Invertebrates, Birds, Ecosystem, Farfield Environment, Fish, Marine Mammals, Nearfield Habitat, Reptiles, Socio-economics, Marine Spatial Planning
Annex IV - Investigating Environmental Effects of Wave and Tidal Devices Through International Cooperation Copping, A., et al. April 2014 Conference Paper Marine Energy general, Tidal, Wave Energy Removal, Noise, Static Device Fish, Marine Mammals
Annex IV - International Collaboration to Investigate Environmental Effects of Wave and Tidal Devices Copping, A., et al. April 2014 Presentation Marine Energy general, Tidal, Wave
Annex I: Movements and Diving Behaviour of Juvenile Grey Seals in Areas of High Tidal Energy Thompson, D. July 2012 Report Marine Energy general, Tidal Dynamic Device Marine Mammals, Pinnipeds
Annapolis Tidal Station January 1984 Project Site OES-Environmental Marine Energy general, Riverine, Tidal
Animals Interacting with Wave and Tidal Devices Andrea Copping July 2014 Blog Article Tidal, Wave
Anglesey Skerries Tidal Stream Array Planned Project Site OES-Environmental Marine Energy general, Tidal
Analysis of Bird and Marine Mammal Data for Fall of Warness Tidal Test Site, Orkney Robbins, A. January 2012 Report Marine Energy general, Tidal Birds, Seabirds, Shorebirds, Waterfowl, Marine Mammals, Pinnipeds
Analysing the potentials and effects of multi-use between tidal energy development and environmental protection and monitoring: A case study of the inner sound of the Pentland Firth Sangiuliano, S. August 2018 Journal Article Marine Energy general, Tidal Socio-economics
An Overview of the Environmental Impact of Non-Wind Renewable Energy Systems in the Marine Environment OSPAR Commission January 2006 Conference Paper Marine Energy general, Tidal, Wave
An Overview Of Ocean Renewable Energy Technologies Bedard, R., et al. June 2010 Magazine Article Marine Energy general, OTEC, Tidal, Wave, Wind Energy general, Offshore Wind
An Introduction to Marine Renewable Energy Sheilds, M. January 2014 Book Chapter Marine Energy general, Tidal, Wave, Wind Energy general, Offshore Wind
An Integrated Solution to Real Time Marine Mammal Monitoring for Tidal Turbines Bromley, P., Boake, C., Broudic, M. September 2015 Conference Paper Marine Energy general, Tidal Static Device Marine Mammals
An Evaluation of the Use of Shore-Based Surveys for Estimating Spatial Overlap between Deep-Diving Seabirds and Tidal Stream Turbines Waggitt, J., Bell, P., Scott, B. December 2014 Journal Article Marine Energy general, Tidal Birds
An assessment of the impacts of a tidal renewable energy scheme on the eutrophication potential of the Severn Estuary, UK Kadiri, M., et al. October 2014 Journal Article Marine Energy general, Tidal
Alteration to the shallow-water tides and tidal asymmetry by tidal-stream turbines Potter, D January 2019 Thesis Marine Energy general, Tidal Dynamic Device, Energy Removal
Agent-Based Modelling of fish collisions with tidal turbines Rossington, K., Benson, T. May 2019 Presentation Marine Energy general, Tidal Dynamic Device Fish
Advancing a Key Consenting Risk for Tidal Energy: The Risk of Marine Mammal Collision for In-Stream Tidal Energy Devices Booth, C., et al. April 2015 Conference Paper Marine Energy general, Tidal Dynamic Device Marine Mammals
Advances in Research to Understand the Impacts of Wave and Tidal Energy Devices in the United States Brown-Saracino, J. May 2014 Presentation Marine Energy general, Tidal, Wave
Admiralty Inlet Post-Installation Environmental Monitoring Summary Polagye, B. April 2013 Report Marine Energy general, Tidal
Admiralty Inlet Pilot Tidal Project Tehani Montaron April 2014 Blog Article Tidal
Admiralty Inlet Pilot Tidal Project Planned Project Site OES-Environmental Marine Energy general, Tidal
Admiralty Inlet Final License Application Snohomish County Public Utility District No. 1 March 2012 Report Marine Energy general, Tidal Chemicals, Dynamic Device, EMF, Energy Removal, Noise Benthic Invertebrates, Fish, Marine Mammals, Socio-economics
Admiralty Inlet Final Environmental Assessment Snohomish County Public Utility District No. 1 August 2013 Report Marine Energy general, Tidal Fish, Marine Mammals, Socio-economics
Admiralty Inlet Basin Flow Model Pacific Northwest National Laboratory January 2012 Video Marine Energy general, Tidal Energy Removal
Adjusting the Financial Risk of Tidal Current Projects by Optimising the 'Installed Capacity/Capacity Factor'-Ratio Already During the Feasibility Stage Bucher, R., Couch, S. June 2013 Journal Article Marine Energy general, Tidal Socio-economics
Acoustic Tracking of Fish Movements in the Minas Passage and FORCE Demonstration Area: Pre-Turbine Baseline Studies (2011-2013) Redden, A., Stokesbury, M. January 2014 Report Marine Energy general, Tidal Fish
Acoustic Monitoring of Beluga Whale Interactions with Cook Inlet Tidal Energy Project ORPC Alaska February 2014 Report Marine Energy general, Tidal Static Device Marine Mammals, Cetaceans
Accommodating Wave and Tidal Energy - Control and Decision in Scotland Johnson, K., Kerr, S., Side, J. September 2012 Journal Article Marine Energy general, Tidal, Wave Socio-economics
A World First: Swansea Bay Tidal Lagoon in Review Waters, S., Aggidis, G. April 2016 Journal Article Marine Energy general, Tidal
A Tool for Simulating Collision Probabilities of Animals with Marine Renewable Energy Devices Schmitt, P., et al. November 2017 Journal Article Marine Energy general, Tidal Dynamic Device
A Tidal Power Project Wright, G. September 2011 Journal Article Marine Energy general, Tidal Socio-economics
A Techno-Economic Analysis of Tidal Energy Technology Johnstone, C., et al. January 2013 Journal Article Marine Energy general, Tidal Socio-economics
A systematic review of transferable solution options for the environmental impacts of tidal lagoons Elliott, K., et al. January 2019 Journal Article Marine Energy general, Tidal
A strategic policy framework for promoting the marine energy sector in Spain Vazquez, S., Astariz, S., Iglesias, G. December 2015 Journal Article Tidal, Wave, Offshore Wind Legal and Policy
A Self-Contained Subsea Platform for Acoustic Monitoring of the Environment Around Marine Renewable Energy Devices - Field Deployments at Wave and Tidal Energy Sites in Orkney, Scotland Williamson, B., et al. January 2016 Journal Article Marine Energy general, Tidal, Wave Dynamic Device, Static Device Birds, Fish, Marine Mammals
A Scenario-Based Approach to Evaluating Potential Environmental Impacts Following a Tidal Barrage Installation Kidd, I., et al. November 2015 Journal Article Marine Energy general, Tidal Energy Removal Ecosystem
A Review of the Potential Water Quality Impacts of Tidal Renewable Energy Systems Kadiri, M., et al. January 2012 Journal Article Marine Energy general, Tidal Energy Removal Nearfield Habitat
A Review of the Potential Impacts of Wave and Tidal Energy Development on Scotland's Marine Environment Aquatera June 2014 Report Marine Energy general, Tidal, Wave Nearfield Habitat
A Review of the Current Understanding of the Hydro-Environmental Impacts of Energy Removal by Tidal Turbines Nash, S., Phoenix, A. December 2017 Journal Article Marine Energy general, Tidal Energy Removal
A Review of the Application of Lifecycle Analysis to Renewable Energy Systems Lund, C., Biswas, W. April 2008 Journal Article Marine Energy general, Riverine, Tidal, Wave, Wind Energy general Socio-economics, Life Cycle Assessment
A Review of Marine Bird Diving Behaviour: Assessing Underwater Collision Risk with Tidal Turbines Robbins, A., et al. May 2014 Presentation Marine Energy general, Tidal Dynamic Device Birds, Seabirds
A Quality Management Review of Scotland's Sectoral Marine Plan for Tidal Energy Sangiuliano, S. August 2016 Report Marine Energy general, Tidal Socio-economics, Legal and Policy
A Political, Economic, Social, Technology, Legal and Environmental (PESTLE) Approach for Risk Identification of the Tidal Industry in the United Kingdom Kolios, A., Read, G. September 2013 Journal Article Marine Energy general, Tidal Socio-economics
A Political, Economic, Social, Technology, Legal and Environmental (PESTLE) Approach for Risk Identification of the Tidal Industry in the United Kingdom Kolios, A., Read, G. October 2013 Journal Article Marine Energy general, Tidal Socio-economics, Legal and Policy, Stakeholder Engagement
A Modeling Study of Tidal Energy Extraction and the Associated Impact on Tidal Circulation in a Multi-Inlet Bay System of Puget Sound Wang, T., Yang, Z. December 2017 Journal Article Marine Energy general, Tidal Energy Removal Farfield Environment
A Modeling Study of the Potential Water Quality Impacts from In-Stream Tidal Energy Extraction Wang, T., Yang, Z., Copping, A. January 2015 Journal Article Marine Energy general, Tidal Energy Removal Nearfield Habitat
A Holistic Method for Selecting Tidal Stream Energy Hotspots Under Technical, Economic and Functional Constraints Vazquez, A., Iglesias, G. June 2016 Journal Article Marine Energy general, Tidal Socio-economics
A French Application Case of Tidal Turbine Certification Paboeuf, S., Macadre, L., Sun, P. June 2016 Conference Paper Marine Energy general, Tidal Energy Removal
A framework to evaluate the environmental impact of OCEAN energy devices Mendoza, E., et al. June 2019 Journal Article Marine Energy general, Ocean Current, OTEC, Tidal, Wave, Offshore Wind Dynamic Device, Noise Benthic Invertebrates, Birds, Seabirds, Shorebirds, Ecosystem, Farfield Environment, Fish, Marine Mammals, Cetaceans, Pinnipeds, Nearfield Habitat, Environmental Impact Assessment
A Framework for Environmental Risk Assessment and Decision-Making for Tidal Energy Development in Canada [Presentation] Isaacman, L., Daborn, G., Redden, A. April 2014 Presentation Marine Energy general, Tidal Socio-economics, Legal and Policy
A Framework for Environmental Risk Assessment and Decision-Making for Tidal Energy Development in Canada Isaacman, L., Daborn, G., Redden, A. August 2012 Report Marine Energy general, Tidal Socio-economics
A Finite Element Circulation Model for Embayments with Drying Intertidal Areas and its Application to the Quoddy Region of the Bay of Fundy Greenberg, D., et al. January 2005 Journal Article Marine Energy general, Tidal
A Diving Bird Collision Risk Assessment Framework for Tidal Turbines Grant, M., Trinder, M., Harding, N. January 2014 Report Marine Energy general, Tidal Dynamic Device Birds
A Coordinated Action Plan for Addressing Collision Risk for Marine Mammals and Tidal Turbines Hutchison, I., Copping, A. August 2016 Workshop Article Marine Energy general, Tidal Dynamic Device Marine Mammals
A Conflict of Greens: Green Development Versus Habitat Preservation - The Case of Incheon, South Korea Ko, Y., Schubert, D., Hester, R. June 2011 Magazine Article Marine Energy general, Tidal Birds, Ecosystem, Socio-economics
A comprehensive insight into tidal stream energy farms in Iran Radfar, S., et al. November 2017 Journal Article Marine Energy general, Tidal Socio-economics
A Comparison of Underwater Noise at Two High Energy Sites Willis, M., et al. September 2011 Conference Paper Marine Energy general, Tidal Noise
A Comparison of Numerical Modelling Techniques for Tidal Stream Turbine Analysis Masters, I., et al. July 2015 Journal Article Marine Energy general, Tidal
A 1:8.7 Scale Water Tunnel Verification & Validation of an Axial Flow Water Turbine Fontaine, A., et al. August 2013 Report Marine Energy general, Riverine, Tidal
3D modelling of the impacts of in-stream horizontal-axis Tidal Energy Converters (TECs) on offshore sandbank dynamics Chatzirodou, A., Karunarathna, H., Reeve, D. October 2019 Journal Article Marine Energy general, Tidal Energy Removal
2018 State of the Sector Report: Marine Renewable Energy in Canada Marine Renewables Canada June 2018 Report Marine Energy general, Riverine, Tidal, Wave, Wind Energy general, Offshore Wind

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