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: 670
Title Author Date Type of Contentsort descending Technology Type Stressor Receptor
Pentland Firth MeyGen AR1500 and HS1500 Strain Gauge Data November 2016 Dataset Marine Energy general, Tidal Dynamic Device Marine Mammals
Pentland Firth MeyGen AR1500 and HS1500 Video Camera Data November 2016 Dataset Marine Energy general, Tidal Dynamic Device Birds, Fish, Marine Mammals
Pentland Firth Meygen AR1500 FLOWBEC Platform ADVOcean 5MHz Data October 2015 Dataset Marine Energy general, Tidal Dynamic Device
Pentland Firth Meygen AR1500 FLOWBEC Platform Multi-beam and Echosounder Data October 2015 Dataset Marine Energy general, Tidal Dynamic Device Birds, Fish, Marine Mammals
Pentland Firth Meygen AR1500 FLOWBEC Platform Fluorometer Data October 2015 Dataset Marine Energy general, Tidal Ecosystem
Fall of Warness HyTide 1000 Observational Data Informing Video Analysis June 2014 Dataset Marine Energy general, Tidal Dynamic Device Birds, Fish, Marine Mammals
Pentland Firth MeyGen Harbour Seal Telemetry Data October 2016 Dataset Marine Energy general, Tidal Dynamic Device Marine Mammals, Pinnipeds
Pentland Firth Meygen AR1500 Passive Acoustic Monitoring Data: SGDS Project February 2017 Dataset Marine Energy general, Tidal Dynamic Device Marine Mammals, Cetaceans
Pentland Firth Meygen AR1500 Multi-beam Echosounder Data: SGDS Project February 2017 Dataset Marine Energy general, Tidal Dynamic Device Birds, Fish, Marine Mammals, Cetaceans, Pinnipeds
Fall of Warness HyTide 1000 Observational Data of Seal Haul-Outs During the Breeding Season June 2010 Dataset Marine Energy general, Tidal Marine Mammals, Pinnipeds
EMEC Fall of Warness Boat-Based Wildlife Surveys (RESPONSE Project) May 2012 Dataset Marine Energy general, Tidal Birds
EMEC Fall of Warness High-Intensity Wildlife Observation Data June 2012 Dataset Marine Energy general, Tidal Dynamic Device Birds, Marine Mammals
EMEC Fall of Warness Wildlife Observation Data July 2005 Dataset Marine Energy general, Tidal Birds, Marine Mammals
Fall of Warness HyTide 1000 Video Monitoring Data of Biofouling May 2014 Dataset Marine Energy general, Tidal Static Device Benthic Invertebrates
Fall of Warness HyTide 1000 Video Monitoring Data of Wildlife Interactions May 2014 Dataset Marine Energy general, Tidal Dynamic Device Birds, Fish, Marine Mammals
EMEC Fall of Warness FLOWBEC Platform Fluorometer Monitoring Data June 2012 Dataset Marine Energy general, Tidal Ecosystem
EMEC Fall of Warness FLOWBEC Platform Multi-Beam Sonar and Echosounder Data June 2012 Dataset Marine Energy general, Tidal Dynamic Device Birds, Fish, Marine Mammals
EMEC Fall of Warness FLOWBEC Platform Acoustic Doppler Velocimeter Data June 2013 Dataset Marine Energy general, Tidal Dynamic Device
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
The Role of Tidal Asymmetry in Characterising the Tidal Energy Resource of Orkney Neill, S., Hashemi, M., Lewis, M. May 2014 Presentation Marine Energy general, Tidal
Impacts of Tidal-Stream Energy Converter (TEC) Arrays in Relation to the Natural Variability of Sedimentary Processes Robins, P., Neill, S., Lewis, M. May 2014 Presentation Marine Energy general, Tidal Energy Removal
The Modelling of Tidal Turbine Farms using Multi-Scale, Unstructured Mesh Models Kramer, S., et al. May 2014 Presentation Marine Energy general, Tidal
Tidal Energy, Underwater Noise and Marine Mammals Carter, C., Wilson, B., Burrows, M. May 2014 Presentation Marine Energy general, Tidal Noise Marine Mammals
Monitoring Benthic Habitats and Biodiversity at the Tidal Energy Site of Paimpol-Brehat (Brittany, France) Carlier, A., et al. May 2014 Presentation Marine Energy general, Tidal Benthic Invertebrates
Marine Mammals and Tidal Turbines: Understanding True Collision Risk Sparling, C., et al. May 2014 Presentation Marine Energy general, Tidal Dynamic Device Marine Mammals
Tracking Porpoise Underwater Movements in Tidal Rapids using Drifting Hydrophone Arrays. Filling a Key Information Gap for Assessing Collision Risk Gordon, J., et al. May 2014 Presentation Marine Energy general, Tidal Marine Mammals, Cetaceans
Movement Patterns of Seals in Tidally Energetic Sites: Implications for Renewable Energy Development Hastie, G., et al. May 2014 Presentation Marine Energy general, Tidal Marine Mammals, Pinnipeds
Multi-Disciplinary Risk Identification and Evaluation for the Tidal Industry Kolios, A., Read, G., Loannou, A. April 2014 Presentation Marine Energy general, Tidal
Using the FLOWBEC Seabed Frame to Understand Underwater Interactions between Diving Seabirds, Prey, Hydrodynamics and Tidal and Wave Energy Structures Williamson, B., et al. April 2014 Presentation Marine Energy general, Tidal, Wave Birds, Seabirds
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
SeaGen Tidal Turbine - An Exercise in Adaptive Management Ainsworth, D. April 2011 Presentation Marine Energy general, Tidal Dynamic Device, Noise, Static Device Birds, Seabirds, Waterfowl, Marine Mammals
Monitoring the environmental interactions of tidal devices - how do we achieve what is required in a practical and cost effective manner whilst retaining focus on the key issues to assist the consenting of future projects? Foubister, L. April 2018 Presentation Marine Energy general, Tidal Socio-economics
Comparative effects of climate change and tidal stream energy extraction in the NW European continental shelf De Dominicis, M., Wolf, J., Murray, R. April 2018 Presentation Marine Energy general, Tidal Farfield Environment
Environmental Monitoring of the Paimpol-Brehat Tidal Project Barillier, A., Carlier, A. February 2016 Presentation Marine Energy general, Tidal Noise, Static Device Benthic Invertebrates, Marine Mammals
What Should a Condition Monitoring System Look like for a Tidal Turbine? Marnoch, J. February 2016 Presentation Marine Energy general, Tidal
Detecting Potential and Actual Turbine-Marine Life Interactions: A Call for the Development of Best Practices Redden, A. November 2014 Presentation Marine Energy general, Tidal Dynamic Device, Static Device Fish, Marine Mammals
GHYDRO: Methodology Guide for Assessment of Environmental Impacts of Tidal Stream Energy Technologies at Sea Lejart, M. November 2014 Presentation Marine Energy general, Tidal Socio-economics, Legal and Policy
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
Historic Environment Guidance for Wave and Tidal Renewable Energy Robertson, P., Shaw, A. April 2014 Presentation Marine Energy general, Tidal, Wave Socio-economics
Agent-Based Modelling of fish collisions with tidal turbines Rossington, K., Benson, T. May 2019 Presentation Marine Energy general, Tidal Dynamic Device Fish
Marine Mammals and Tidal Turbines: What are the Issues of Concern and how are they being Resolved? Wilson, B., Hastie, G., Benjamins, S. April 2014 Presentation Marine Energy general, Tidal 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
Marine Radar Derived Current Vector Mapping at a Planned Commercial Tidal Stream Turbine Array in the Pentland Firth Bell, P., et al. May 2014 Presentation Marine Energy general, Tidal
OERA Webinar Series: Finite Element Analysis to Assess Fish Mortality from Interactions with Tidal Turbine Blades Fyffe, N. May 2018 Presentation Marine Energy general, Tidal Dynamic Device Fish
Tidal Current Power Development in Korea Lee, K., et al. November 2009 Presentation Marine Energy general, Tidal
The Reality of Environmental Compliance: A Tidal Perspective Barr, S. April 2009 Presentation Marine Energy general, Tidal Socio-economics
Use of Animal Tracking Technology to Assess Potential Risks of Tidal Turbine Interactions with Fish Redden, A., et al. May 2014 Presentation Marine Energy general, Tidal Fish
La Rance Tidal Power Plant: 40-Year Operation Feedback - Lessons Learnt de Laleu, V. October 2009 Presentation Marine Energy general, Tidal Energy Removal, Static Device Birds, Farfield Environment, Fish, Marine Mammals, Nearfield Habitat
SuperGen Research Helps to Answer Long Standing Problem of Shoreline 'Exposure' Beharie, R., Side, J. January 2011 Presentation Marine Energy general, Tidal, Wave Energy Removal Nearfield Habitat
Can tidal stream turbines change the tides in the Pentland Firth, and is there an acceptable limit? Murray, R. April 2018 Presentation Marine Energy general, Tidal Dynamic Device Farfield Environment
Outer Bay of Fundy Tidal Energy Development: Where the Leviathans Live Trowse, G., Malinka, C. October 2014 Presentation Marine Energy general, Tidal
Developing Capabilities for Tidal Hydrokinetic Blade Strike Monitoring Polagye, B., et al. September 2011 Presentation Marine Energy general, Tidal Dynamic Device
Better Together: The Implications of Tidal Resource Interactions from Resource Calculation to Policy and Governance Woolf, D., Easton, M. May 2014 Presentation Marine Energy general, Tidal Socio-economics, Legal and Policy
Assessing the Impact of Rows of Tidal-Stream Turbines on the Overtides of the M2 Potter, D, Folkard, A., Ilić, S. April 2018 Presentation Marine Energy general, Tidal Dynamic Device Farfield Environment
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
Listening In Riddoch, L. August 2009 Magazine Article Marine Energy general, Tidal Noise Birds, Seabirds, Marine Mammals, Pinnipeds
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
Using Adaptive Management To Resolve Uncertainties For Wave And Tidal Energy Projects Oram, C., Marriott, C. January 2010 Magazine Article Marine Energy general, Tidal, Wave 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
Silt-Proof Measures: Following Analysis of Data Measured out of Baishakou Tidal Power Station, Measures were Proposed to Control Sediment in the Reservoir Yunchen, L. February 2004 Magazine Article Marine Energy general, Tidal Energy Removal Nearfield Habitat
Admiralty Inlet Pilot Tidal Project Tehani Montaron April 2014 Blog Article Tidal
Harbor porpoise (Phocoena phocoena) monitoring at the FORCE Test Site, Canada Melissa Oldreive, Dom Tollit, and Daniel J. Hasselman (FORCE) March 2019 Blog Article Tidal
Tidal Lagoons: Another Technique for Capturing Marine Renewable Energy Matthew Preisser July 2016 Blog Article Tidal
INORE: Sharing is Knowing Cameron McNatt and Michele Martini October 2014 Blog Article OTEC, Tidal, Wave, Offshore Wind
Remote Sensor Platforms for Environmental Monitoring at FORCE, Canada Anna Redden, Haley Viehman, and Melissa Oldreive June 2017 Blog Article Tidal
Are Larvae and other Planktonic Organisms at Risk from Tidal Energy Development? Andrea Copping August 2016 Blog Article Tidal
Animals Interacting with Wave and Tidal Devices Andrea Copping July 2014 Blog Article Tidal, Wave
Planned Swansea Bay Tidal Lagoon Jonathan Whiting May 2013 Blog Article Tidal
West Coast Organization Channels Energy for Marine Renewables Marisa McNatt and Matthew Sanders (POET) November 2018 Blog Article Marine Energy general, Tidal, Wave, Wind Energy general, Offshore Wind
Interactions of Marine and Avian Animals Around Marine Energy Devices in Scotland Molly Grear May 2014 Blog Article Tidal, Wave

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