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Tides

Tides. Description of tides. High water: a water level maximum ("high tide") Low water: a water level minimum ("low tide") Tidal range: the difference between high and low tide Spring Tide: full moon and new moon (14.77 days) Neap Tide : 1 st quarter and 3 rd quarter (14.77 days).

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Tides

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  1. Tides

  2. Description of tides • High water: a water level maximum ("high tide") • Low water: a water level minimum ("low tide") • Tidal range: the difference between high and low tide • Spring Tide: full moon and new moon (14.77 days) • Neap Tide: 1st quarter and 3rd quarter (14.77 days) • Intertidal zone • High tide • Low tide

  3. Renewable sources There are few existing machineries set in oceans for tidal energy. A lot of concepts are still being designed for the future,. Tidal energy is only renewable energy, since tides occur because of the gravitational pull of the moon. Tides are always around as we are alive In Ireland, suspended from a crossbeam that can be raised above the water’s surface for easy maintenance are two 600 kW rotors. The advantage of this technology lies in the high density of water: Relatively small underwater rotors can be used to generate the same amount of electricity as larger wind turbines on land and sea. At the same time, however, the position in saltwater places special demands on drives, materials, and lubricants.

  4. Primary uses Tidal energy is produced by the surge of ocean waters during the rise and fall of tides. Tidal energy is a renewable source of energy.During the 20th century, engineers developed ways to use tidal movement to generate electricity in areas where there is a significant tidal range—the difference in area between high tide and low tide. All methods use special generators to convert tidal energy into electricity.Tidal energy production is still in its infancy. The amount of power produced so far has been small. There are currently two commercial-sized tidal power plants operating in the world. One is located in La Rance, France; the other is in Annapolis Royal, Nova Scotia, Canada. There is a third experimental plant operating in KislayaGuba, Russia. The United States has no tidal plants and only a few sites where tidal energy could be produced at a reasonable price. France, England, Canada, and Russia have much more potential to use this type of energy.

  5. Largest users of Tidal energy Norway, Australia, Italy, Korea

  6. Pros of Tidal energy ProsConsistent Power - Tides move constantly throughout the day, which provides a consistent stream of electricity generation capacity.Pollution-Free - By taking advantage of only the tide, tidal power creates no greenhouse gas emissions or water pollutants.Low Operating Costs - Once installed there are few ongoing operating costs or labor costs, unless there is a device breakdown.Renewable - No material resources are used or changed in the production of tidal power, making it a truly renewable power form.Minimal Visual Impact - Tidal power devices are fully or nearly completely submerged in water well offshore. This reduces the “damaging of water views” that has been associated with offshore wind turbines.Efficient - Tidal Power converts roughly 80% of the kinetic energy into electricity, as opposed to coal and oil which convert only 30% of the energy held within.Locations - There are numerous locations for tidal power around the world. Other websites online have this number at 40, however the coast of British Columbia, Canada has 89 alone.

  7. Cons of tidal energy ConsDevice Breakdown - Strong ocean storms and salt water corrosion can damage the devices, which could increase the cost of construction to increase durability and/or cause frequent breakdowns.Shifting Tides - Changes in tidal movement could substantially reduce efficiency of TSGs.Marine Life Affected - Sea life could be harmed by the blades in the open and Venturi turbines. The floor mounting of TSGs could also disrupt the habitats of different sea life and plants.High Initial Costs - The high cost of the different TSGs and cost of installing power lines underwater could lengthen the payback period and be cost prohibitive based on the characteristics and size of each project.Few Implemented - There are relatively few commercial installations as compared to other technologies, such as wind and solar farms. As such, additional difficulties implementing these TSG devices could arise.Reduced Sea Usage - The potentially larger footprint of TSG farms could reduce shipping and recreation areas.

  8. The monthly tidal cycle(29½ days) About every 7 days, Earth alternates between: • Spring tide • Alignment of Earth-Moon-Sun system (syzygy) • Lunar and solar bulges constructively interfere • Large tidal range • Neap tide • Earth-Moon-Sun system at right angles (quadrature) • Lunar and solar bulges destructively interfere • Small tidal range

  9. The Bay of Fundy: Site of the world’s largest tidal range

  10. La Rance tidal power plant at St. Malo, France.

  11. Bay of Fundy low tides vs high • Alma at High Tide • Alma at Low Tide

  12. Pollutants! After the construction of the tidal plant, tidal power causes no pollution.

  13. Websites used http://greenthefuture.com/TIDALPOWER_PROSCONS.html http://oceanservice.noaa.gov/facts/tides.html http://www.alstom.com/power/renewables/ocean-energy/tidal-energy/ http://education.yahoo.com/reference/encyclopedia/entry/tide

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