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| | If you take a glance at the people around you, you will realise that many of them have yellow teeth. How exactly can you stand straight from the crowd, and turn one for this selected few with the right smile?<br><br> |
| {{mergefrom|Tidal kite|date=December 2013}}
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| [[File:Evopod in Strangford Lough 2008.jpg|thumb|[[Evopod]] - A semi-submerged floating approach tested in [[Strangford Lough]].]]
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| A '''tidal stream generator,''' often referred to as a '''tidal energy converter (TEC)''' is a machine that extracts [[energy]] from moving masses of water, in particular [[tides]], although the term is often used in reference to machines designed to extract energy from run of river or tidal estuarine sites. Certain types of these machines function very much like underwater [[wind turbine]]s, and are thus often referred to as '''tidal turbines'''. They were first conceived in the 1970s during the oil crisis.<ref name="ASAP. Web. 8 October 2009">Jones, Anthony T., and Adam Westwood. "Power from the oceans: wind energy industries are growing, and as we look for alternative power sources, the growth potential is through the roof. Two industry watchers take a look at generating energy from wind and wave action and the potential to alter." The Futurist 39.1 (2005): 37(5). GALE Expanded Academic ASAP. Web. 8 October 2009.</ref>
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| Tidal stream generators are the cheapest and the least ecologically damaging among the [[Tidal power#Generating methods|three main forms]] of [[tidal power]] generation.<ref>{{cite web|title=Tidal power|url=http://www.esru.strath.ac.uk/EandE/Web_sites/01-02/RE_info/Tidal%20Power.htm#streams|accessdate=1 November 2010}}</ref>
| | To take advantage teeth whitening results can consider employing a dentist for this teeth tooth whitening. This is because the possible utilization of lasers in conjunction with the whitening products may offer you much faster and are more durable results.<br><br>When you eat, minute pieces among the food you consume get gathered up inside your mouth, and then the bacteria convert and also energy . to chemicals. Later, the acids get motley with the saliva and convert to plaque. The deposition of plaque with your teeth will lead to major tooth [https://www.youtube.com/watch?v=4To0cBm6IsM best dentist in florida] problems. Oral cavities is one of the major problems because of plaque. As brushing is important, the time also dentist vital that use fluoride based toothpaste for your teeth. The existence of of fluoride in any toothpaste permit prevent bacteria in mouth area and can also help inside of prevention of tooth tooth decay.<br><br>If a fall or a brawl has left you having a tooth missing, bridges may what you should. Commonly referred to as pontics, dental bridges fill in the gaps caused by missing dental. Two crowns are placed on either side of the gap and the pontic or maybe the fake tooth is placed between many. If you are you looking for more about [https://www.youtube.com/watch?v=4To0cBm6IsM best dentist in florida] stop by our own web-page. The entire tooth is held by natural teeth or implant.<br><br>Not all dental problems come from inside. Fights, car accidents, and other facial trauma can lead to the need the oral surgeon. When teeth get pushed back into the gum line through impact, it can be extremely painful, and naturally unsightly. An everyday family dentist is not able to achieve much for you personally personally in in instances such like this. Going in for surgery in all probability anyone's regarding a good time, yet it could be the only reasonable to be able to restore your smile and restore function to your teeth.<br><br>If your teeth are heavily stained, you need to know that it might take multiple treatments a person decide to obtain that bright smile that you desire. Teeth which usually are stained and discolored, aside from a few shades off white, harder to treat, no matter which solutions you opt for. Badly discolored teeth are likely to require several treatments before improvement are visible.<br><br>Another significant problem is uneven or broken teeth, most of these tooth problems can be fixed, except for sitting at home. You will have to check out the doctor and buying a dental check up for yourself so quite possibly able to inform you which is the dental method that you can follow to get that perfect smile of yours. |
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| == Similarity to wind turbines ==
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| Tidal stream generators draw energy from water currents in much the same way as [[wind turbine]]s draw energy from air currents. However, the potential for power generation by an individual tidal turbine can be greater than that of similarly rated wind energy turbine. The higher density of water relative to air (water is about 800 times the density of air) means that a single generator can provide significant power at low tidal flow velocities compared with similar wind speed.<ref>"Surfing Energy's New Wave" Time International 16 June 2003: 52+. http://www.time.com/time/magazine/article/0,9171,457348,00.html</ref> Given that power varies with the density of medium and the cube of velocity, water speeds of nearly one-tenth the speed of wind provide the same power for the same size of turbine system; however this limits the application in practice to places where the tide moves at speeds of at least 2 knots (1 m/s) even close to [[neap tide]]s. Furthermore, at higher speeds in a flow between 2 to 3 metres per second in seawater a tidal turbine can typically access four times as much energy per rotor swept area as a similarly rated power wind turbine.
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| == Types of tidal stream generators ==
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| No standard tidal stream generator has emerged as the clear winner, among a large variety of designs. Several prototypes have shown promise with many companies making bold claims, some of which are yet to be independently verified, but they have not operated commercially for extended periods to establish performances and rates of return on investments.
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| The [[European Marine Energy Centre]] recognizes six principal types of tidal energy converter. They are horizontal axis turbines, vertical axis turbines, oscillating hydrofoils, venturi devices, Archimedes screws and [[tidal kite]]s.<ref>{{cite web|url=http://www.emec.org.uk/tidal_devices.htm|author=EMEC|title=Tidal Energy Devices|accessdate=5 October 2008}}</ref><ref>{{cite web|title=EMEC: Tidal devices|url=http://www.emec.org.uk/marine-energy/tidal-devices/|accessdate=8 April 2013}}</ref>
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| === Axial turbines === <!-- [[Tidal power]] points to this section -->
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| [[File:Bottom Mounted Turbines.png|thumb|Bottom-mounted axial turbines]]
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| [[File:Cable Tethered Turbine.png|thumb|A cable tethered turbine]]
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| These are close in concept to traditional windmills, but operating under the sea. They have the most prototypes currently operating, including:
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| The AR-1000, a 1MW turbine developed by Atlantis Resources Corporation that was successfully deployed at the EMEC facility during the summer of 2011. The AR series are commercial scale, horizontal axis turbines designed for open ocean deployment. AR turbines feature a single rotor set with fixed pitch blades. The AR turbine is rotated as required with each tidal exchange. This is done in the slack period between tides and held in place for the optimal heading for the next tide. AR turbines are rated at 1MW @ 2.65 m/s of water flow velocity.{{citation needed|date=April 2013}}
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| The [[Kvalsund]] installation is south of [[Hammerfest]], [[Energy in Norway|Norway]].<ref>{{cite web|url=http://www.newscientist.com/article.ns?id=dn4188 |title=First power station to harness Moon opens - September 22, 2003 |publisher=New Scientist |date=2003-09-22 |accessdate=2013-04-28}}</ref> Although still a prototype, a turbine with a reported capacity of 300 kW was connected to the grid on 13 November 2003. | |
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| Seaflow, a 300 kW Periodflow marine current propeller type turbine was installed by [[Marine Current Turbines]] off the coast of [[Lynmouth]], [[Devon]], England, in 2003.<ref>{{cite web|url=http://www.reuk.co.uk/Worlds-First-Open-Sea-Tidal-Turbine.htm |title=Read about the first open-sea tidal turbine generator off Lynmouth, Devon |publisher=REUK |date= |accessdate=2013-04-28}}</ref> The 11m diameter turbine generator was fitted to a steel pile which was driven into the seabed. As a prototype, it was connected to a dump load, not to the grid.
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| In April 2007 [[Verdant Power]]<ref name="autogenerated1">{{cite web|url=http://www.verdantpower.com/what-initiative |title=Verdant Power |publisher=Verdant Power |date=2012-01-23 |accessdate=2013-04-28}}</ref> began running a prototype project in the [[East River]] between [[Queens]] and [[Roosevelt Island]] in New York City; it was the first major tidal-power project in the United States.<ref>[http://www.technologyreview.com/Energy/18567/ MIT ''Technology Review'', April 2007]. Retrieved August 24, 2008.</ref> The strong currents pose challenges to the design: the blades of the 2006 and 2007 prototypes broke and new reinforced turbines were installed in September 2008.<ref>{{cite news | title=N.Y. Tests Turbines to Produce Power. City Taps Current Of the East River | author=Robin Shulman | date=September 20, 2008 | publisher=Washington Post | url=http://www.washingtonpost.com/wp-dyn/content/article/2008/09/19/AR2008091903729.html | accessdate=2008-10-09}}</ref><ref>{{cite news | title=Power From the Restless Sea Stirs the Imagination | author=Kate Galbraith | date=September 22, 2008 | publisher=New York Times | url=http://www.nytimes.com/2008/09/23/business/23tidal.html?em | accessdate=2008-10-09}}</ref>
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| Following the Seaflow trial, a full-size prototype, called [[SeaGen]], was installed by Marine Current Turbines in Strangford Lough in Northern Ireland in April 2008. The turbine began to generate at full power of just over 1.2 MW in December 2008<ref>[http://www.marineturbines.com/3/news/ ]{{dead link|date=April 2013}}</ref> and is reported to have fed 150 kW into the grid for the first time on 17 July 2008, and has now contributed more than a gigawatt hour to consumers in Northern Ireland.<ref>[http://www.marineturbines.com/3/news// First connection to the grid]{{dead link|date=April 2013}}</ref> It is currently the only commercial scale device to have been installed anywhere in the world.<ref>{{cite web|url=http://www.marineturbines.com/18/projects/19/seagen/ |title=· Sea Generation Tidal Turbine |publisher=Marineturbines.com |date= |accessdate=2013-04-28}}</ref> SeaGen is made up of two axial flow rotors, each of which drive a generator. The turbines are capable of generating electricity on both the ebb and flood tides because the rotor blades can pitch through 180˚.<ref>Marine Current Turbines. "Technology." Marine Current Turbines. Marine Current Turbines, n.d. Web. 5 October 2009. <http://www.marineturbines.com/21/ technology/>.</ref>
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| OpenHydro,<ref>{{cite web|url=http://www.openhydro.com/ |title=OpenHydro |publisher=OpenHydro |date= |accessdate=2013-04-28}}</ref> an Irish company exploiting the Open-Centre Turbine developed in the U.S., has a prototype being tested at the [[European Marine Energy Centre]] (EMEC), in Orkney, Scotland.
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| [[File:Evopod lighter.jpg|thumb|A 3D model of an Evopod tidal turbine]]
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| A prototype semi-submerged floating tethered tidal turbine called [[Evopod]] has been tested since June 2008<ref>[http://www.oceanflowenergy.com/news-details.aspx?id=6] Ocean Flow Energy Ltd announce the start of their testing in Strangford Lough</ref> in Strangford Lough, [[Northern Ireland]] at 1/10 scale. The UK company developing it is called Ocean Flow Energy Ltd.<ref>{{cite web|url=http://www.oceanflowenergy.com/ |title=Ocean Flow Energy company website |publisher=Oceanflowenergy.com |date= |accessdate=2013-04-28}}</ref> The advanced hull form maintains optimum heading into the tidal stream and is designed to operate in the peak flow of the water column.
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| In 2010, Tenax Energy of Australia proposed to put 450 turbines off the coast of [[Darwin, Australia]], in the [[Clarence Strait (Northern Territory)|Clarence Strait]]. The turbines would feature a rotor section approximately 15 metres in diameter with a slightly larger gravity base slighter larger. The turbines would operate in deep water well below shipping channels. Each turbine is forecast to produce energy for between 300 and 400 homes.<ref>{{cite web | title= Tidal power project could run all homes | author= Nigel Adlam | date=2010-01-29 | publisher= [[Northern Territory News]]| url= http://www.ntnews.com.au/article/2010/01/29/119431_ntnews.html | accessdate=2010-06-06 }}</ref>
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| Tidalstream, a UK-based company, commissioned a scaled-down Triton 3 turbine in the Thames.<ref>{{cite web|url=http://www.tidalstream.co.uk |title=Triton Home |publisher=Tidalstream.co.uk |date= |accessdate=2013-04-28}}</ref> It can be floated to its site, installed without cranes, jack-ups or divers and then ballasted into operating position. At full scale the Triton 3 in 30-50m deep water has a 3MW capacity, and the Triton 6 in 60-80m water has a capacity of up to 10MW, depending on the flow. Both platforms have man-access capability both in the operating position and in the float-out maintenance position.
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| === Crossflow turbines === <!-- [[Tidal power]] points to this section -->
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| Invented by [[Georges Darreius]] in 1923 and patented in 1929, these turbines can be deployed either vertically or horizontally.
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| The [[Gorlov helical turbine|Gorlov turbine]]<ref>[http://www.gcktechnology.com/ Gorlov Turbine]{{dead link|date=April 2013}}</ref> is a variant of the Darrieus design featuring a helical design that is in a large scale, commercial pilot in South Korea,<ref>{{cite web|url=http://www.worldchanging.com/archives/002383.html |title=Gorlov Turbines in Koreas |publisher=Worldchanging.com |date=1999-02-22 |accessdate=2013-04-28}}</ref> starting with a 1MW plant that opened in May 2009<ref>{{cite web|url=http://www.hydroworld.com/index/display/article-display/2336952618/articles/hrhrw/hydroindustrynews/ocean-tidal-streampower/south-korea_starts.html |title=South Korea starts up, to expand 1-MW Jindo Uldolmok tidal project|publisher=Hydro World|year=2009}}</ref> and expanding to 90MW by 2013. Neptune Renewable Energy's Proteus project<ref>{{cite web|url=http://www.neptunerenewableenergy.com/ |title=Proteus |publisher=Neptunerenewableenergy.com |date=2013-02-07 |accessdate=2013-04-28}}</ref> employs a shrouded vertical axis turbine that can be used to form an array in mainly estuarine conditions.
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| In April 2008, the Ocean Renewable Power Company, LLC (ORPC) successfully completed testing its proprietary turbine-generator unit (TGU) prototype at ORPC's [[Cobscook Bay]] and [[Western Passage]] tidal sites near [[Eastport, Maine]].<ref>{{cite web | url=http://www.masshightech.com/stories/2008/07/28/weekly9-Tide-is-slowly-rising-in-interest-in-ocean-power.html/ | title=Tide is slowly rising in interest in ocean power | publisher=Mass High Tech: The Journal of New England Technology | date=August 1, 2008 | accessdate=2008-10-11}}</ref> The TGU is the core of the OCGen technology and utilizes advanced design cross-flow (ADCF) turbines to drive a permanent magnet generator located between the turbines and mounted on the same shaft. ORPC has developed TGU designs that can be used for generating power from river, tidal and deep water ocean currents.
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| Trials in the [[Strait of Messina]], Italy, started in 2001 of the [[Kobold turbine]] concept.<ref>[http://www.dpa.unina.it/adag/eng/renewable_energy.html A.D.A.Group]{{dead link|date=April 2013}}</ref>
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| === Flow augmented turbines ===
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| [[File:Sea Bed Turbine.png|thumb|A shrouded turbine]]
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| Using flow augmentation measures, for example a duct or shroud, the incident power available to a turbine can be increased. The most common example uses a [[Shrouded tidal turbine|shroud]] to increase the flow rate through the turbine, which can be of either the axial or crossflow type.
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| The Australian company Tidal Energy Pty Ltd undertook successful commercial trials of efficient [[shrouded tidal turbine]]s on the [[Gold Coast, Queensland]] in 2002. Tidal Energy has commenced a rollout of their shrouded turbine for a remote Australian community in northern Australia where there are some of the fastest flows ever recorded (11 m/s, 21 knots) – two small turbines will provide 3.5 MW. Another larger 5 meter diameter turbine, capable of 800 kW in 4 m/s of flow, is planned for deployment as a tidal powered desalination showcase near Brisbane Australia in October 2008.
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| === Oscillating devices ===
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| Oscillating devices do not have a rotating component, instead making use of [[aerofoil]] sections which are pushed sideways by the flow. Oscillating stream power extraction was proven with the omni- or bi-directional Wing'd Pump windmill.<ref>{{cite web|url=http://econologica.org/watermill.htm |title=Wing'd Pump Windmill |publisher=Econologica.org |date= |accessdate=2013-04-28}}</ref> During 2003 a 150 kW oscillating hydroplane device, the Stingray, was tested off the Scottish coast.<ref>{{cite web|url=http://www.engb.com/ |title=Stingray |publisher=Engb.com |date= |accessdate=2013-04-28}}</ref> The Stingray uses hydrofoils to create oscillation, which allows it to create hydraulic power. This hydraulic power is then used to power a hydraulic motor, which then turns a generator.<ref name="ASAP. Web. 8 October 2009"/>
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| Pulse Tidal operate an oscillating hydrofoil device in the Humber estuary.<ref>{{cite web|url=http://www.youtube.com/watch?v=z07OV0d9NS4 |title=BBC Look North "A tidal power project in the Humber has generated its first batch of electricity" |publisher=Youtube.com |date=2009-08-06 |accessdate=2013-04-28}}</ref> Having secured funding from the EU, they are developing a commercial scale device to be commissioned 2012.<ref>{{cite web|author=Don Pratt |url=http://www.theengineer.co.uk/pulse-tidal-receives-eu-grant/1000213.article |title=EU Grant reported by The Engineer |publisher=Theengineer.co.uk |date= |accessdate=2013-04-28}}</ref>
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| The bioSTREAM tidal power conversion system, uses the [[biomimicry]] of swimming species, such as shark, tuna, and mackerel using their highly efficient [[Thunniform]] mode propulsion. It is produced by Australian company BioPower Systems. | |
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| A 2 kW prototype relying on the use of two oscillating hydrofoils in a tandem configuration has been developed at Laval University and tested successfully near Quebec City, Canada, in 2009. A hydrodynamic efficiency of 40% has been achieved during the field tests.<ref>{{cite web|url=http://hydrolienne.fsg.ulaval.ca/en |title=HAO turbine |publisher=Hydrolienne.fsg.ulaval.ca |date= |accessdate=2013-04-28}}</ref>
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| === Venturi effect ===
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| {{See also|Venturi effect}}
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| Venturi effect devices use a shroud or duct in order to generate a pressure differential which is used to run a secondary hydraulic circuit which is used to generate power. A device, the Hydro Venturi, is to be tested in San Francisco Bay.<ref>{{cite web|author=Seth Wolf |url=http://www.sfbg.com/38/43/news_tidal.html |title=San Francisco Bay Guardian News |publisher=Sfbg.com |date=2004-07-27 |accessdate=2013-04-28}}</ref>
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| == Commercial plans ==
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| [[RWE]]'s [[npower (UK)|npower]] announced that it is in partnership with Marine Current Turbines to build a tidal farm of SeaGen turbines off the coast of [[Anglesey]] in Wales,<ref>{{cite news| url=http://www.forbes.com/markets/feeds/afx/2008/02/07/afx4626015.html | title=RWE plans 10.5 MW sea current power plant off Welsh coast - Forbes.com}} {{Dead link|date=April 2011|bot=RjwilmsiBot}}</ref> near [[The Skerries, Anglesey|the Skerries]].<ref>[http://www.rwe.com/web/cms/en/309778/rwe-npower-renewables/sites/projects-in-development/marine/skerries/the-proposal/ RWE npower renewables Sites > Projects in Development > Marine > Skerries > The Proposal : Anglesey Skerries Tidal Stream Array]. Retrieved February 26, 2010.</ref>
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| In November 2007, British company Lunar Energy announced that, in conjunction with [[E.ON]], they would be building the world's first deep-sea tidal energy farm off the coast of Pembrokshire in Wales. It will provide electricity for 5,000 homes.
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| Eight underwater turbines, each 25 metres long and 15 metres high, are to be installed on the sea bottom off St David's peninsula. Construction is due to start in the summer of 2008 and the proposed tidal energy turbines, described as "a wind farm under the sea", should be operational by 2010.{{update after|2010|12|31}}
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| British Columbia Tidal Energy Corp. plans to deploy at least three 1.2 MW turbines in the [[Campbell River (Vancouver Island)|Campbell River]] or in the surrounding coastline of British Columbia by 2009.<ref>{{cite web|url=http://www.alternative-energy-news.info/press/tidal-power-west-coast-canada/ |title=Tidal Power Coming to West Coast of Canada |publisher=Alternative-energy-news.info |date=2007-11-08 |accessdate=2013-04-28}}</ref>{{update after|2009|12|31}}
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| [[Alderney Renewable Energy Ltd]] is planning{{when|date=April 2013}} to use tidal turbines to extract power from the notoriously strong [[tidal race]]s around [[Alderney]] in the [[Channel Islands]]. It is estimated that up to 3 GW could be extracted. This would not only supply the island's needs but also leave a considerable surplus for export.<ref name="arel">{{cite web|url=http://www.are.gb.com/index.php |title=Alderney Renewable Energy Ltd |publisher=Are.gb.com |date= |accessdate=2013-04-28}}</ref>
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| [[Nova Scotia Power]] has selected OpenHydro's turbine for a tidal energy demonstration project in the Bay of Fundy, Nova Scotia, Canada and Alderney Renewable Energy Ltd for the supply of tidal turbines in the Channel Islands.<ref>[http://www.openhydro.com Open Hydro]</ref>
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| [[Pulse Tidal]] are designing a commercial device{{when|date=April 2013}} with seven other companies who are expert in their fields.<ref>[http://www.pulsegeneration.co.uk/?q=node/54 Pulse Press Release]</ref> The consortium was awarded an €8 million EU grant to develop the first device, which will be deployed in 2012{{where?|date=April 2013}} and generate enough power for 1,000 homes.
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| [[ScottishPower Renewables]] are planning to deploy ten 1MW HS1000 devices designed by [[Hammerfest Strom]] in the [[Sound of Islay]].{{when|date=April 2013}}<ref>[http://www.islayenergytrust.org.uk Islay Energy Trust]</ref>
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| == Energy calculations ==
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| === Turbine power ===
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| Tidal energy converters can have varying modes of operating and therefore varying power output. If the power coefficient of the device "<math> C_P</math>" is known, the equation below can be used to determine the power output of the hydrodynamic subsystem of the machine. This available power cannot exceed that imposed by the [[Betz limit]] on the power coefficient, although this can be circumvented to some degree by placing a [[Shrouded tidal turbine|turbine in a shroud or duct]]. This works, in essence, by forcing water which would not have flowed through the turbine through the rotor disk. In these situations it is the frontal area of the duct, rather than the turbine, which is used in calculating the power coefficient and therefore the Betz limit still applies to the device as a whole.
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| The energy available from these kinetic systems can be expressed as:
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| :<math>P = \frac{\rho A V^3}{2} C_P</math>
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| where:
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| :<math> C_P</math> = the turbine power coefficient
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| :''P'' = the power generated (in watts)
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| :<math>\rho</math> = the density of the water (seawater is 1027 kg/m³)
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| :''A'' = the sweep area of the turbine (in m²)
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| :''V'' = the velocity of the flow
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| Relative to an open turbine in free stream, ducted turbines are capable of as much as 3 to 4 times the power of the same turbine rotor in open flow.<ref name="autogenerated2">http://www.cyberiad.net/library/pdf/bk_tidal_paper25apr06.pdf tidal paper on cyberiad.net</ref>
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| === Resource assessment ===
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| While initial assessments of the available energy in a channel have focus on calculations using the kinetic energy flux model, the limitations of tidal power generation are significantly more complicated. For example, the maximum physical possible energy extraction from a strait connecting two large basins is given to within 10% by:<ref>Atwater, J.F., Lawrence, G.A. (2008) Limitations on Tidal Power Generation in a Channel, Proceedings of the 10th World Renewable Energy Congress. (pp 947–952)</ref><ref>Garrett, C. and Cummins, P. (2005). "The power potential of tidal currents in channels." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 461, London. The Royal Society, 2563–2572</ref>
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| :<math> P = 0.22\, \rho\, g\, \Delta H_\text{max}\, Q_\text{max}</math>
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| where
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| :<math>\rho</math> = the density of the water (seawater is 1027 kg/m³)
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| :''g'' = gravitational acceleration (9.80665 m/s<sup>2</sup>)
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| :<math>\Delta H_\text{max}</math> = maximum differential water surface elevation across the channel
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| :<math>Q_\text{max}</math>= maximum volumetric flow rate though the channel.
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| == Potential sites ==
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| As with wind power, selection of location is critical for the tidal turbine. Tidal stream systems need to be located in areas with fast currents where natural flows are concentrated between obstructions, for example at the entrances to bays and rivers, around rocky points, headlands, or between islands or other land masses. The following potential sites are under serious consideration:
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| * [[Pembrokeshire]] in Wales<ref>[http://www.builderandengineer.co.uk/news/general/pembrokeshire-tidal-barrage-moves-forward-934.html Builder & '''Engineer - Pembrokeshire tidal''' barrage moves forward<!-- Bot generated title -->]</ref>
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| * [[River Severn]] between Wales and England<ref>[http://www.walesonline.co.uk/news/politics-news/tm_headline=severn-balancing-act-hain&method=full&objectid=19718602&siteid=50082-name_page.html Severn balancing act]</ref>
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| *[[Cook Strait]] in New Zealand<ref>[http://www.energybulletin.net/6046.html NZ: Chance to turn the tide of power supply | EnergyBulletin.net | Peak Oil News Clearinghouse<!-- Bot generated title -->]</ref>
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| * [[Kaipara Tidal Power Station|Kaipara Harbour]] in New Zealand<ref name="Energy NZ">{{cite news|url=http://www.contrafedpublishing.co.nz/Energy+NZ/Harnessing+the+power+of+the+sea.html|title=Harnessing the power of the sea|publisher=Energy NZ, Vol 1, No 1|date=Winter 2007}}</ref>
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| *[[Bay of Fundy]]<ref>[http://media.cleantech.com/2269/bay-of-fundy-to-get-three-test-turbines Bay of Fundy to get three test turbines | Cleantech.com<!-- Bot generated title -->]</ref> in Canada.
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| *[[East River]]<ref>{{Cite news |first=Robin |last=Shulman | id={{issn|0740-5421}} | title = N.Y. Tests Turbines to Produce Power | work = [[The Washington Post]] | accessdate = 2008-09-20 |date = September 20, 2008 | url = http://www.washingtonpost.com/wp-dyn/content/article/2008/09/19/AR2008091903729.html?hpid=topnews&sub=AR}}</ref><ref>[http://verdantpower.com/what-initiative Verdant Power<!-- Bot generated title -->]</ref> in the [[USA]]
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| *[[Golden Gate]] in the [[San Francisco Bay]]<ref>http://deanzaemtp.googlepages.com/PGEbacksnewstudyofbaystidalpower.pdf</ref>
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| *[[Piscataqua River]] in [[New Hampshire]]<ref>[http://www.seacoastonline.com/apps/pbcs.dll/article?AID=/20070519/NEWS/705190344 Tidal power from Piscataqua River?<!-- Bot generated title -->]</ref>
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| *The Race of [[Alderney]] and [[The Swinge]] in the [[Channel Islands]]<ref name="arel" />
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| *The Sound of Islay, between [[Islay]] and [[Jura, Scotland|Jura]] in Scotland<ref name="Islay Energy Trust">[http://www.islayenergytrust.org.uk Islay Energy Trust - Developing Renewables for the community]</ref>
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| *[[Pentland Firth]] between [[Caithness]] and the [[Orkney]] Islands, [[Scotland]]
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| *[[Humboldt County, California]] in the [[United States]]
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| *[[Columbia River, Oregon]] in the [[United States]]
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| Modern advances in [[turbine]] technology may eventually see large amounts of power generated from the ocean, especially tidal currents using the tidal stream designs but also from the major thermal current systems such as the [[Gulf Stream]], which is covered by the more general term [[marine current power]]. Tidal stream turbines may be arrayed in high-velocity areas where natural tidal current flows are concentrated such as the west and east coasts of Canada, the [[Strait of Gibraltar]], the [[Bosporus]], and numerous sites in [[Southeast Asia]] and Australia. Such flows occur almost anywhere where there are entrances to bays and rivers, or between land masses where water currents are concentrated.
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| == Environmental impacts ==
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| Very little direct research or observation of tidal stream systems exists. Most direct observations consist of releasing tagged fish upstream of the device(s) and direct observation of mortality or impact on the fish.
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| One study of the Roosevelt Island Tidal Energy (RITE, Verdant Power) project in the East River (New York City), utilized 24 split beam hydroacoustic sensors ([[scientific echosounder]]) to detect and track the movement of fish both upstream and downstream of each of six turbines. The results suggested (1) very few fish using this portion of the river, (2) those fish which did use this area were not using the portion of the river which would subject them to blade strikes, and (3) no evidence of fish traveling through blade areas. {{Citation needed|date=October 2010}}
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| Work is currently being conducted by the Northwest National Marine Renewable Energy Center ([[NNMREC]]<ref>[http://depts.washington.edu/nnmrec/]</ref>)to explore and establish tools and protocols for assessment of physical and biological conditions and monitor environmental changes associated with tidal energy development.
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| == See also ==
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| * [[Marine energy]]
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| * [[Renewable energy]]
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| * [[Tidal power]]
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| * [[Wave power]]
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| * [[Wind turbine]]
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| == References ==
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| {{Reflist|2}}
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| {{DEFAULTSORT:Tidal Stream Generator}}
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| [[Category:Tidal power]]
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