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: 693
Title Author Date Type of Content Technology Type Stressorsort descending Receptor
Admiralty Inlet Pilot Tidal Project Planned Project Site Annex IV Marine Energy general, Tidal
Annapolis Tidal Station January 1984 Project Site Annex IV Marine Energy general, Riverine, Tidal
Atlantis Resources Corporation at EMEC August 2011 Project Site Annex IV Marine Energy general, Tidal
BaiShakou Tidal Power Station August 1978 Project Site Annex IV Marine Energy general, Tidal
Clarence Strait Tidal Energy Project Planned Project Site Annex IV Marine Energy general, Tidal
Cobscook Bay Tidal Energy Project September 2012 Project Site Annex IV Marine Energy general, Tidal
EMEC Fall of Warness Grid-Connected Tidal Test Site July 2005 Project Site Annex IV Marine Energy general, Tidal
EMEC Shapinsay Sound Non Grid-Connected Nursery Tidal Test Site September 2011 Project Site Annex IV Marine Energy general, Tidal
Enermar Project January 2001 Project Site Annex IV Marine Energy general, Tidal
Fri-El Seapower - Messina Project January 2007 Project Site Annex IV Marine Energy general, Tidal
Fundy Ocean Research Center for Energy (FORCE) Test Site September 2009 Project Site Annex IV Marine Energy general, Tidal
Haishan Tidal Power Plant December 1975 Project Site Annex IV Marine Energy general, Tidal
Sound of Islay Demonstration Tidal Array Planned Project Site Annex IV Marine Energy general, Tidal
Kvalsund Tidal Turbine Prototype August 2003 Project Site Annex IV Marine Energy general, Tidal
Jiangxia Pilot Tidal Power Plant January 1980 Project Site Annex IV Marine Energy general, Tidal
La Rance Tidal Barrage November 1966 Project Site Annex IV Marine Energy general, Tidal
MORILD II Tidal Power Plant November 2010 Project Site Annex IV Marine Energy general, Tidal
Ocean Flow Energy - Sanda Sound August 2014 Project Site Annex IV Marine Energy general, Tidal
OpenHydro Alderney Planned Project Site Annex IV Marine Energy general, Tidal
OpenHydro at EMEC May 2008 Project Site Annex IV Marine Energy general, Tidal
Ramsey Sound December 2015 Project Site Annex IV Marine Energy general, Tidal
San Remo January 2006 Project Site Annex IV Marine Energy general, Tidal
Sihwa Tidal Power Plant August 2011 Project Site Annex IV Marine Energy general, Tidal
Strangford Lough - MCT (SeaGen) July 2008 Project Site Annex IV Marine Energy general, Tidal
Race Rocks Tidal Energy Project September 2006 Project Site Annex IV Marine Energy general, Tidal
Roosevelt Island Tidal Energy (RITE) Project Demonstration December 2006 Project Site Annex IV Marine Energy general, Tidal
Torr Head Project Planned Project Site Annex IV Marine Energy general, Tidal
Uldolmok Tidal Power Station May 2009 Project Site Annex IV Marine Energy general, Tidal
Wanxiang-I Project January 2002 Project Site Annex IV Marine Energy general, Tidal
Wanxiang-II Project January 2005 Project Site Annex IV Marine Energy general, Tidal
Western Passage Tidal Energy Project Planned Project Site Annex IV Marine Energy general, Tidal
Westray South Tidal Project Planned Project Site Annex IV Marine Energy general, Tidal
Yell Sound September 2002 Project Site Annex IV Marine Energy general, Tidal
Acoustic Effects of Tidal Energy May 2010 Research Study Annex IV Marine Energy general, Tidal Noise Fish, Marine Mammals
Acoustic Impact Assessment of Offshore Energy Project January 2009 Research Study Annex IV Marine Energy general, Tidal Noise Fish, Marine Mammals
Aqua Renewable Energy Technologies (Aqua-RET) October 2006 Research Study Annex IV Marine Energy general, Tidal, Wave Socio-economics
Aquatic Renewable Energy Technologies 2 (Aqua-RET2) January 2009 Research Study Annex IV Marine Energy general, Tidal, Wave Socio-economics
Flow, Water Column & Benthic Ecology 4D (FLOWBEC) January 2011 Research Study Annex IV Marine Energy general, Tidal, Wave Energy Removal Benthic Invertebrates, Birds, Fish
Hydrographic and Sediment Field Surveys January 2010 Research Study Annex IV Marine Energy general, Tidal Benthic Invertebrates
Impacts of TEC and WEC Array Operation on Sediment Dynamics August 2008 Research Study Annex IV Marine Energy general, Tidal, Wave Energy Removal Farfield Environment, Nearfield Habitat
Large Scale Interactive Coupled 3D Modelled for Wave and Tidal Energy Resource and Environmental Impact (TeraWatt) February 2012 Research Study Annex IV Marine Energy general, Tidal, Wave Dynamic Device, Static Device Benthic Invertebrates, Fish
Marine Renewable Energy Development in Scotland (MREDS) May 2007 Research Study Annex IV Marine Energy general, Tidal, Wave Benthic Invertebrates, Birds, Seabirds, Fish, Marine Mammals, Nearfield Habitat
Marine Renewable Energy and the Environment (MaREE) January 2010 Research Study Annex IV Marine Energy general, Tidal, Wave Dynamic Device, Energy Removal, Noise, Static Device Benthic Invertebrates, Birds, Seabirds, Fish, Marine Mammals, Nearfield Habitat
Monitoring and Evaluation of Spatially Managed Areas (MESMA) January 2012 Research Study Annex IV Marine Energy general, Tidal, Wave, Wind Energy general, Offshore Wind Static Device Socio-economics, Legal and Policy
Ocean Current Turbine Rotor Noise August 2010 Research Study Annex IV Marine Energy general, Ocean Current, Tidal Noise Marine Mammals
Offshore Power Production and Marine Stakeholders: From Understanding Conflict to Impact Mitigation January 2009 Research Study Annex IV Marine Energy general, Tidal, Wave Benthic Invertebrates, Ecosystem, Fish, Socio-economics
Peninsula Research Institute for Marine Renewable Energy (PRIMaRE) January 2009 Research Study Annex IV Marine Energy general, Tidal, Wave Chemicals, Dynamic Device, EMF, Energy Removal, Noise, Static Device Bats, Benthic Invertebrates, Birds, Seabirds, Ecosystem, Farfield Environment, Fish, Marine Mammals, Nearfield Habitat, Socio-economics, Navigation
Pilot Marine Spatial Plan for the Pentland Firth and Orkney Waters April 2012 Research Study Annex IV Marine Energy general, Tidal, Wave Noise, Static Device Benthic Invertebrates, Birds, Fish, Marine Mammals, Nearfield Habitat, Socio-economics, Legal and Policy, Marine Spatial Planning
Quantifying Benefits and Impacts of Fishing Exclusion Zones on Bio-Resources around Marine Renewable Energy Installations (QBEX) January 2012 Research Study Annex IV Marine Energy general, Ocean Current, Tidal, Wave Dynamic Device, Static Device Benthic Invertebrates, Fish, Marine Mammals
Sub-Mesoscale Flow Regime Modeling and the Influence of Energy Extraction at a Tidal Energy Site April 2012 Research Study Annex IV Marine Energy general, Tidal Energy Removal Nearfield Habitat
SuperGen Marine Energy Research October 2003 Research Study Annex IV Marine Energy general, Tidal, Wave Dynamic Device, Energy Removal, Static Device Benthic Invertebrates, Birds, Marine Mammals
The Ecological Impacts of Tidal Energy Development October 2008 Research Study Annex IV Marine Energy general, Tidal Benthic Invertebrates, Fish
Understanding Benthic Productivity on Artificial Structures: Maximising the Benefit of Marine Renewable Energy Devices May 2011 Research Study Annex IV Marine Energy general, Tidal, Wave Dynamic Device, Static Device Benthic Invertebrates
Understanding How Marine Renewable Device Operations Influence Fine Scale Habitat Use & Behaviour of Marine Vertebrates (RESPONSE) January 2011 Research Study Annex IV Marine Energy general, Tidal, Wave Static Device Marine Mammals
Hydrokinetic Turbine Effects on Fish Swimming Behaviour February 2012 Research Study Annex IV Marine Energy general, Tidal Dynamic Device, Static Device Fish
Planned Swansea Bay Tidal Lagoon Jonathan Whiting May 2013 Blog Article Tidal
A Comparison of Underwater Noise at Two High Energy Sites Willis, M., et al. September 2011 Conference Paper Marine Energy general, Tidal Noise
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 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 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
A Techno-Economic Analysis of Tidal Energy Technology Johnstone, C., et al. January 2013 Journal Article Marine Energy general, Tidal Socio-economics
The Muskeget Channel Tidal Energy Project: A Unique Case Study in the Licensing and Permitting of a Tidal Energy Project in Massachusetts Barrett, S. July 2013 Journal Article Marine Energy general, Tidal Socio-economics
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
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
Admiralty Inlet Basin Flow Model Pacific Northwest National Laboratory January 2012 Video Marine Energy general, Tidal Energy Removal
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
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 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 Experimental Investigation on Cavitation, Noise, and Slipstream Characteristics of Ocean Stream Turbines Wang, D., Altar, M., Sampson, R. August 2006 Journal Article Marine Energy general, Tidal Energy Removal, Noise
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
Assessing the Sensitivity of Seabird Populations to Adverse Effects from Tidal Stream Turbines and Wave Energy Devices Furness, R., et al. June 2012 Journal Article Marine Energy general, Tidal, Wave Dynamic Device, Energy Removal, Static Device Birds
Assessment Of Tidal Energy Removal Impacts On Physical Systems: Development Of MHK Module And Analysis Of Effects On Hydrodynamics Yang, Z., Wang, T. September 2011 Report Marine Energy general, Tidal Energy Removal Farfield Environment
Assessment of Strike of Adult Killer Whales by an OpenHydro Tidal Turbine Blade Carlson, T., et al. January 2014 Report Marine Energy general, Tidal Dynamic Device Marine Mammals
Assessment of Tidal and Wave Energy Conversion Technologies in Canada Fisheries and Oceans Canada November 2009 Report Marine Energy general, Tidal, Wave Energy Removal, Noise, Static Device Benthic Invertebrates, Farfield Environment, Fish, Marine Mammals, Nearfield Habitat
Assessment of Zooplankton Injury and Mortality Associated With Underwater Turbines for Tidal Energy Production Schlezinger, D., Taylor, C., Howes, B. July 2013 Journal Article Marine Energy general, Tidal Dynamic Device Ecosystem
Atlas of UK Marine Renewable Energy Resources ABP Marine Environmental Research May 2008 Website Marine Energy general, Tidal, Wave, Wind Energy general, Offshore Wind
Birds and Wave & Tidal Stream Energy: An Ecological Review McCluskie, A., Langston, R., Wilkinson, N. January 2012 Report Marine Energy general, Tidal, Wave Chemicals, Dynamic Device, Energy Removal, Noise, Static Device Birds, Raptors, Seabirds, Shorebirds
Broadband Acoustic Environment at a Tidal Energy Site in Puget Sound Xu, J., et al. March 2012 Journal Article Marine Energy general, Tidal Noise
Challenges and Opportunities in Tidal and Wave Power Jacobson, P., Rao, K. December 2011 Book Chapter Marine Energy general, Tidal, Wave Socio-economics
Changes in Area, Geomorphology and Sediment Nature of Salt Marshes in the Oosterschelde Estuary (SW Netherlands) Due to Tidal Changes de Jong, D., de Jong, Z., Mulder, J. May 1994 Journal Article Marine Energy general, Tidal Energy Removal Nearfield Habitat
Characteristics of Underwater Ambient Noise at a Proposed Tidal Energy Site in Puget Sound Bassett, C., Thomson, J., Polagye, B. September 2010 Conference Paper Marine Energy general, Tidal Noise
China Funds Development Of New Tidal Current Energy Devices Yanbo, G., Yan, L., Changlei, M. April 2011 Magazine Article Marine Energy general, Tidal Socio-economics
Cobscook Bay Tidal Energy Project: 2012 Environmental Monitoring Report ORPC Maine March 2013 Report Marine Energy general, Tidal Dynamic Device, Energy Removal, Noise Benthic Invertebrates, Farfield Environment, Fish, Marine Mammals, Nearfield Habitat
Collision Risk of Fish with Wave and Tidal Devices ABP Marine Environmental Research July 2010 Report Marine Energy general, Tidal, Wave Dynamic Device Fish
Depth Averaged Currents at Admiralty Inlet Pacific Northwest National Laboratory January 2012 Video Marine Energy general, Tidal
Detection of Marine Mammals and Effects Monitoring at the NSPI (OpenHydro) Turbine Site in the Minas Passage during 2010 Tollit, D., et al. February 2011 Report Marine Energy general, Tidal Marine Mammals, Cetaceans
Detection of Tidal Turbine Noise: A Pre-Installation Case Study for Admiralty Inlet, Puget Sound Polagye, B., et al. February 2012 Report Marine Energy general, Tidal Noise Marine Mammals
Development of a Stereo Camera System for Monitoring Hydrokinetic Turbines Joslin, J., Polagye, B., Parker-Stetter, S. October 2012 Conference Paper Marine Energy general, Tidal Dynamic Device Nearfield Habitat
EMEC Tidal Test Facility Fall of Warness Eday, Orkney: Environmental Statement Foubister, L. June 2005 Report Marine Energy general, Tidal Benthic Invertebrates, Marine Mammals, Socio-economics, Environmental Impact Assessment
Effect Of Tidal Stream Power Generation On The Region-wide Circulation In A Shallow Sea Shapiro, G. February 2011 Journal Article Marine Energy general, Riverine, Tidal Energy Removal Farfield Environment
Effects Of Tidal Turbine Noise On Fish Hearing And Tissues Halvorsen, M., Carlson, T., Copping, A. September 2011 Report Marine Energy general, Tidal Noise Fish
Electromagnetic Field Study Slater, M., et al. September 2010 Report Marine Energy general, Tidal, Wave EMF
Environmental Effects of Tidal Energy Development: Proceedings of a Scientific Workshop Polagye, B., et al. April 2011 Workshop Article Marine Energy general, Tidal Socio-economics
Current State of Knowledge on the Environmental Impacts of Tidal and Wave Energy Technology in Canada Isaacman, L., Lee, K. November 2009 Report Marine Energy general, Tidal, Wave Chemicals, Dynamic Device, EMF, Energy Removal, Noise, Static Device Farfield Environment, Nearfield Habitat
Environmental Scoping Report Westray South Tidal Array SSE Renewables October 2011 Report Marine Energy general, Tidal Noise, Static Device Birds, Fish, Marine Mammals, Reptiles, Socio-economics
Environmental and Ecological Effects of Ocean Renewable Energy Development: A Current Synthesis Boehlert, G., Gill, A. June 2010 Journal Article Marine Energy general, OTEC, Tidal, Wave, Wind Energy general, Offshore Wind Static Device Nearfield Habitat
Epibenthic Assessment of a Renewable Tidal Energy Site Sheehan, E., et al. January 2013 Journal Article Marine Energy general, Tidal Benthic Invertebrates, Nearfield Habitat
Equitable Testing and Evaluation of Marine Energy Extraction Devices in terms of Performance, Cost and Environmental Impact EquiMar March 2012 Report Marine Energy general, Tidal, Wave Socio-economics, Life Cycle Assessment
Estimating Effects of Tidal Power Projects and Climate Change on Threatened and Endangered Marine Species and Their Food Web Busch, S., Greene, C., Good, T. December 2013 Journal Article Marine Energy general, Tidal Ecosystem, Socio-economics, Climate Change
Estimation of Tidal Power Potential Walters, R., Hiles, C., Tarbotton, M. March 2013 Journal Article Marine Energy general, Tidal

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