http://youtu.be/aJWLHb38Cw4
OCEAN TIDAL POWER
The U.K. is hoping to replace a fifth of its aging coal and gas plants with renewable energy by 2020. According to the government, the U.K. has about 50 percent of Europe’s energy tidal energy resources, and if developed fully, wave and tidal stream energy could meet 20 percent of the U.K.’s demand for power. Already, Scotland is home to the world’s first commercial wave power generator, and the government estimates that marine-based renewable energy like tidal arrays could one day power 750,000 homes in Scotland.
“We’re already leading the world in terms of research and development facilities for the tidal sector, and have more tidal devices being tested in our waters than anywhere else in the world,” Lena Wilson, chief executive of economic agency Scottish Enterprisesaid. “The plans for the Pentland Firth are further evidence of Scotland’s position as one of the key players in the fast growing renewables sector at a global level.” For more on this, click on;
http://thinkprogress.org/climate/2014/08/25/3475122/worlds-biggest-tidal-array-scotland/
Wave Powered Kinetic Energy Production Technology; via @AGreenRoad
http://agreenroad.blogspot.com/2014/04/wave-powered-kinetic-energy-production.html
CHINESE AND EUROPEAN TIDAL POWER PROJECTS
The video demontrates the Dynamic Tidal POWER (DTP) concept and explains, by the use of clear animations, how the concept functions. A number of leading Dutch companies in the field of civil engineering and energy combined their strengths in the POWER group: Partners Offering a Water Energy Revolution. www.powerdtp.nl
Tidal power
Wikipedia; "Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power, mainly electricity.
Although not yet widely used, tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power. Among sources of renewable energy, tidal power has traditionally suffered from relatively high cost and limited availability of sites with sufficiently high tidal ranges or flow velocities, thus constricting its total availability. However, many recent technological developments and improvements, both in design (e.g.dynamic tidal power, tidal lagoons) and turbine technology (e.g. new axial turbines, cross flow turbines), indicate that the total availability of tidal power may be much higher than previously assumed, and that economic and environmental costs may be brought down to competitive levels.
Historically, tide mills have been used both in Europe and on the Atlantic coast of North America. The incoming water was contained in large storage ponds, and as the tide went out, it turned waterwheels that used the mechanical power it produced to mill grain.[1] The earliest occurrences date from the Middle Ages, or even fromRoman times.[2][3] It was only in the 19th century that the process of using falling water and spinning turbines to create electricity was introduced in the U.S. and Europe.[4]
The world's first large-scale tidal power plant is the Rance Tidal Power Station in France, which became operational in 1966.
Generation of tidal energy
Main articles: Tide and Tidal acceleration
Tidal power is taken from the Earth's oceanic tides;tidal forces are periodic variations in gravitational attraction exerted by celestial bodies. These forces create corresponding motions or currents in the world's oceans. Due to the strong attraction to the oceans, a bulge in the water level is created, causing a temporary increase in sea level. When the sea level is raised, water from the middle of the ocean is forced to move toward the shorelines, creating a tide. This occurrence takes place in an unfailing manner, due to the consistent pattern of the moon’s orbit around the earth.[5] The magnitude and character of this motion reflects the changing positions of the Moon and Sun relative to the Earth, the effects of Earth's rotation, and localgeography of the sea floor and coastlines.
Tidal power is the only technology that draws on energy inherent in the orbital characteristics of theEarth–Moon system, and to a lesser extent in the Earth–Sun system. Other natural energies exploited by human technology originate directly or indirectly with the Sun, including fossil fuel, conventional hydroelectric, wind, biofuel, wave andsolar energy. Nuclear energy makes use of Earth's mineral deposits of fissionable elements, while geothermal power taps the Earth's internal heat, which comes from a combination ofresidual heat from planetary accretion (about 20%) and heat produced through radioactive decay (80%).[6]
A tidal generator converts the energy of tidal flows into electricity. Greater tidal variation and higher tidal current velocities can dramatically increase the potential of a site for tidal electricity generation.
Because the Earth's tides are ultimately due to gravitational interaction with the Moon and Sun and the Earth's rotation, tidal power is practically inexhaustible and classified as a renewable energy resource. Movement of tides causes a loss of mechanical energy in the Earth–Moon system: this is a result of pumping of water through natural restrictions around coastlines and consequent viscous dissipation at the seabed and in turbulence. This loss of energy has caused the rotation of the Earth to slow in the 4.5 billion years since its formation. During the last 620 million years the period of rotation of the earth (length of a day) has increased from 21.9 hours to 24 hours;[7] in this period the Earth has lost 17% of its rotational energy. While tidal power will take additional energy from the system, the effect[clarification needed] is negligible and would only be noticed over millions of years.[8]
Generating methods
Tidal power can be classified into three generating methods:
Tidal stream generator
Main article: Tidal stream generator
Tidal stream generators (or TSGs) make use of thekinetic energy of moving water to power turbines, in a similar way to wind turbines that use wind to power turbines. Some tidal generators can be built into the structures of existing bridges, involving virtually no aesthetic problems. Land constrictions such as straits or inlets can create high velocities at specific sites, which can be captured with the use of turbines. These turbines can be horizontal, vertical, open, or ducted and are typically placed near the bottom of the water column.[10]
Tidal barrage
Main article: Tidal barrage
Tidal barrages make use of the potential energy in the difference in height (or hydraulic head) between high and low tides. When using tidal barrages to generate power, the potential energy from a tide is seized through strategic placement of specialized dams. When the sea level rises and the tide begins to come in, the temporary increase in tidal power is channeled into a large basin behind the dam, holding a large amount of potential energy. With the receding tide, this energy is then converted into mechanical energy as the water is released through large turbines that create electrical power through the use of generators.[11] Barrages are essentially damsacross the full width of a tidal estuary.
Dynamic tidal power
Main article: Dynamic tidal power
Dynamic tidal power (or DTP) is an untried but promising technology that would exploit an interaction between potential and kinetic energies in tidal flows. It proposes that very long dams (for example: 30–50 km length) be built from coasts straight out into the sea or ocean, without enclosing an area. Tidal phase differences are introduced across the dam, leading to a significant water-level differential in shallow coastal seas – featuring strong coast-parallel oscillating tidal currents such as found in the UK, China, and Korea.
Tidal lagoon
A newer tidal energy design option is to construct circular retaining walls embedded with turbines that can capture the potential energy of tides. The created reservoirs are similar to those of tidal barrages, except that the location is artificial and does not contain a preexisting ecosystem.[10]
US and Canadian studies in the twentieth century
The first study of large scale tidal power plants was by the US Federal Power Commission in 1924 which if built would have been located in the northern border area of the US state of Maineand the south eastern border area of the Canadian province of New Brunswick, with various dams, powerhouses, and ship locks enclosing the Bay of Fundy and Passamaquoddy Bay (note: see map in reference). Nothing came of the study and it is unknown whether Canada had been approached about the study by the US Federal Power Commission.[12]
There was also a report on the international commission in April 1961 entitled " Investigation of the International Passamaquoddy Tidal Power Project" produced by both the US and Canadian Federal Governments. According to benefit to costs ratios, the project was beneficial to the US but not to Canada. A highway system along the top of the dams was envisioned as well.
A study was commissioned by the Canadian, Nova Scotian and New Brunswick Governments (Reassessment of Fundy Tidal Power) to determine the potential for tidal barrages at Chignecto Bay and Minas Basin – at the end of the Fundy Bay estuary. There were three sites determined to be financially feasible: Shepody Bay (1550 MW), Cumberline Basin (1085 MW), and Cobequid Bay (3800 MW). These were never built despite their apparent feasibility in 1977.[13]
Tidal power development in the UK
The world's first marine energy test facility was established in 2003 to start the development of the wave and tidal energy industry in the UK. Based in Orkney, Scotland, the European Marine Energy Centre (EMEC) has supported the deployment of more wave and tidal energy devices than at any other single site in the world. EMEC provides a variety of test sites in real sea conditions. Its grid connected tidal test site is located at the Fall of Warness, off the island of Eday, in a narrow channel which concentrates the tide as it flows between the Atlantic Ocean and North Sea. This area has a very strong tidal current, which can travel up to 4 m/s (8 knots) in spring tides. Tidal energy developers currently testing at the site include Alstom (formerly Tidal Generation Ltd), ANDRITZ HYDRO Hammerfest, OpenHydro, Scotrenewables Tidal Power, and Voith.[14]
Current and future tidal power schemes
Main article: List of tidal power stations
- The first tidal power station was the Rance tidal power plant built over a period of 6 years from 1960 to 1966 at La Rance, France.[15] It has 240 MW installed capacity.
- 254 MW Sihwa Lake Tidal Power Plant in South Korea is the largest tidal power installation in the world. Construction was completed in 2011.[16][17]
- The first tidal power site in North America is the Annapolis Royal Generating Station,Annapolis Royal, Nova Scotia, which opened in 1984 on an inlet of the Bay of Fundy.[18] It has 20 MW installed capacity.
- The Jiangxia Tidal Power Station, south of Hangzhou in China has been operational since 1985, with current installed capacity of 3.2 MW. More tidal power is planned near the mouth of the Yalu River.[19]
- The first in-stream tidal current generator in North America (Race Rocks Tidal Power Demonstration Project) was installed at Race Rocks on southern Vancouver Island in September 2006.[20][21] The next phase in the development of this tidal current generator will be in Nova Scotia (Bay of Fundy).[22]
- A small project was built by the Soviet Union at Kislaya Guba on the Barents Sea. It has 0.4 MW installed capacity. In 2006 it was upgraded with a 1.2MW experimental advancedorthogonal turbine.
- Jindo Uldolmok Tidal Power Plant in South Korea is a tidal stream generation scheme planned to be expanded progressively to 90 MW of capacity by 2013. The first 1 MW was installed in May 2009.[23]
- A 1.2 MW SeaGen system became operational in late 2008 on Strangford Lough in Northern Ireland.[24]
- The contract for an 812 MW tidal barrage near Ganghwa Island (South Korea) north-west of Incheon has been signed by Daewoo. Completion is planned for 2015.[16]
- A 1,320 MW barrage built around islands west of Incheon is proposed by the South Korean government, with projected construction starting in 2017.[25]
- The Scottish Government has approved plans for a 10MW array of tidal stream generators near Islay, Scotland, costing 40 million pounds, and consisting of 10 turbines – enough to power over 5,000 homes. The first turbine is expected to be in operation by 2013.[26]
- The Indian state of Gujarat is planning to host South Asia's first commercial-scale tidal power station. The company Atlantis Resources planned to install a 50MW tidal farm in the Gulf of Kutch on India's west coast, with construction starting early in 2012.[27]
- Ocean Renewable Power Corporation was the first company to deliver tidal power to the US grid in September, 2012 when its pilot TidGen system was successfully deployed inCobscook Bay, near Eastport.[28]
- In New York City, 30 tidal turbines will be installed by Verdant Power in the East River by 2015 with a capacity of 1.05MW.[29]
- Construction of a 240 MW tidal power plant in the city of Swansea in the UK, estimated to begin in Spring 2015. Once completed, it will generate over 400GWh of electricity per year, enough to power roughly 121,000 homes. Completion is scheduled for 2017, and the project has a projected 120 year lifespan.[30]
Tidal Power Issues
Environmental concerns
Tidal power can have effects on marine life. The turbines can accidentally kill swimming sea life with the rotating blades. Some fish may no longer utilize the area if threatened with a constant rotating or noise-making object. Marine life is a huge factor when placing tidal power energy generators in the water and precautions are made to ensure that as many marine animals as possible will not be affected by it. The Tethys database provides access to scientific literature and general information on the potential environmental effects of tidal energy.[31]
Tidal turbines
The main environmental concern with tidal energy is associated with blade strike and entanglement of marine organisms as high speed water increases the risk of organisms being pushed near or through these devices. As with all offshore renewable energies, there is also a concern about how the creation of EMF and acoustic outputs may affect marine organisms. It should be noted that because these devices are in the water, the acoustic output can be greater than those created with offshore wind energy. Depending on the frequency and amplitude ofsound generated by the tidal energy devices, this acoustic output can have varying effects on marine mammals (particularly those who echolocate to communicate and navigate in the marine environment such as dolphins and whales). Tidal energy removal can also cause environmental concerns such as degrading farfield water quality and disrupting sediment processes. Depending on the size of the project, these effects can range from small traces of sediment build up near the tidal device to severely affecting nearshore ecosystems and processes.[32]
Tidal barrage
Installing a barrage may change the shoreline within the bay or estuary, affecting a large ecosystem that depends on tidal flats. Inhibiting the flow of water in and out of the bay, there may also be less flushing of the bay or estuary, 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. The same acoustic concerns apply to tidal barrages. Decreasing shipping accessibility can become a socio-economic issue, though locks can be added to allow slow passage. However, the barrage may improve the local economy by increasing land access as a bridge. Calmer waters may also allow better recreation in the bay or estuary.[32]
Tidal lagoon
Environmentally, the main concerns are blade strike on fish attempting to enter the lagoon, acoustic output from turbines, and changes in sedimentation processes. However, all these effects are localized and do not affect the entire estuary or bay.[32]
Corrosion
Salt water causes corrosion in metal parts. It can be difficult to maintain tidal stream generators due to their size and depth in the water. The use of corrosion-resistant materials such as stainless steels, high-nickel alloys, copper-nickel alloys, nickel-copper alloys and titanium can greatly reduce, or eliminate, corrosion damage.
Mechanical fluids, such as lubricants, can leak out, which may be harmful to the marine life nearby. Proper maintenance can minimize the amount of harmful chemicals that may enter the environment.
Fouling
The biological events that happen when placing any structure in an area of high tidal currents and high biological productivity in the ocean will ensure that the structure becomes an ideal substrate for the growth of marine organisms. In the references of the Tidal Current Project atRace Rocks in British Columbia this is documented. Also see this page and Several structural materials and coatings were tested by the Lester Pearson College divers to assist Clean Current in reducing fouling on the turbine and other underwater infrastructure.
Structural Health Monitoring
The high load factors resulting from the fact that water is 800 times denser than air and the predictable and reliable nature of tides compared with the wind makes tidal energy particularly attractive for Electric power generation. Condition monitoring is the key for exploiting it cost-efficiently.[33]
Source: http://en.wikipedia.org/wiki/Tidal_powerUSING TIDES AS ENERGY STORAGE DEVICE
ChasAha December 24, 2014 "Think out of the box. Like this unique, yet simple concept.
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Belgium plans to exit nuclear power by 2025.
By Building a WINDMILL ISLAND. Using a combination of windmills and water flow to create CONSTANT FLOW of electricity.
"Using an idea borrowed from hydroelectric dams, the island would be emptied of water when there is a lot of wind, using energy from windmills. When there is an energy shortfall, a lock would be opened to let the sea water back in and at the same time power turbines and generate electricity."
No storage needed. Cool.
Brilliant! 
"
"OCEAN WAVE POWER
Wave Powered Kinetic Energy Production Technology; via @AGreenRoad
http://agreenroad.blogspot.com/2014/04/wave-powered-kinetic-energy-production.html
Wave power is another energy source that is renewable and zero carbon, which can be developed by any nation, state or city that has ocean waves on it's coastline. How much energy is in the waves, compared to the ocean tides and the ocean winds that blow in from the ocean on a nearly constant basis? How much of this zero carbon energy can be tapped, and how soon? The answers for humanity's low cost, pollution free, zero carbon, zero nuclear energy needs are all there. They are just waiting to be tapped and utilized.
Thanks for your generous support!
End
Tidal Power Exceeds 2 Terra Watts Globally, Scotland Leading The Charge For Tide Power Development, Using Tides For Energy Storage
http://agreenroad.blogspot.com/2014/09/tidal-power-exceeds-2-terra-watts.html
For more articles;
Environment, Holistic Living, Health, Self-Healing, Zero Point And Renewable Energy
http://agreenroad.blogspot.com/p/green-energy-green-living.html
http://agreenroad.blogspot.com/2014/09/tidal-power-exceeds-2-terra-watts.html
For more articles;
Environment, Holistic Living, Health, Self-Healing, Zero Point And Renewable Energy
http://agreenroad.blogspot.com/p/green-energy-green-living.html
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