Tidal+Power

**TIDAL POWER..... Rather Than Surfing the Waves, Produce Power From Them.** That's totally gnarly dude.
 * By Mallory Cutler, Ally Gillis, Jackie Diffley **

Tides are caused by the gravitational pull of the moon and sun, and the rotation of the Earth. Near shore, water levels can vary up to 40 feet due to tides. Tidal power is more predictable than wind energy and solar power. A large enough tidal range (10 feet) is needed to produce tidal energy economically. A simple generation system for tidal plants involves a dam, known as a barrage, across an inlet. Sluice gates (gates commonly used to control water levels and flow rates) on the barrage allow the tidal basin to fill on the incoming high tides and to empty through the turbine system on the outgoing tide, also known as the ebb tide. There are two-way systems that generate electricity on both the incoming and outgoing tides. Tidal turbines are basically wind turbines in the water that can be located anywhere there is strong tidal flow. Because water is about 800 times denser than air, tidal turbines have to be much sturdier than wind turbines. [1]

media type="youtube" key="qRUl1mJQHmc" height="405" width="500"[2] This video shows the passage of water threw the turbines and how it converts to energy.

[3] **This picture is of tidal power turbines. The turbines are used to create the energy in non harmful way. **

This arcticle is about The Marine Action Plan,published on March 15,2010 in Britain. The plan will generate enough energy for 15 million houses, but with the engergy prices being so high the goverment istaking procautions for their investment. **
 * RECENT NEWS ARTICLE  [|"Britain Rules the Waves"]

**TIDAL POWER : HOW IT WORKS** 2. The barrage has gates in which it allows the water to flow into the barrage with the incoming tide. The gates are then closed when the tide begins to go back out. ** 4. The tidal range has to be sufficient in order for this to be a practical means to generate power. This range should be in excess of 5 meters otherwise the power generated is not sufficient.[1] **
 * 1. A barrage, which is a huge dam, is built across a river, estuary or bay.
 * 3. The water which is now trapped inside the barrage which is now called a ‘hydrostatic head’. The greater the head the more power can be generated from the out flowing water. There are other gates within the barrage which are now opened; these gates contain hydro-electric generators, very similar to the ones used in Hydropower. These generators are now turned by the out flowing water and power is generated. ****

**Conservation of energy**
 * **The energy of flowing water into kinetic energy**
 * **The transformation of kinetic energy from out flowing water into electrical energy from when the generator turns on.**

**ADVANTAGES** -There is no waste or pollution -Very reliable -We can predict when tides will be in or out -The barrage can help to reduce the damage of very high tidal surges or storms on the land **
 * - **** It is very cheap to maintain

-It changes the coastline completely and the estuaries are flooded so any mud flats or habitats that birds or animals live on are destroyed -Initial building cost is very expensive -Water is not replenished, it cannot flow away so any dirt or pollution lingers around the coast much longer -Silt builds up behind the barrage -Disrupts creatures’ migration in the oceans -Needs a very big piece of sea to be cost effective -Not many sites suitable for this kind of power generation; building the barrage **
 * DISADVANTAGES
 * -Only produces power for about 10 hours of the day [1] **


 * Vocabulary **
 * Barrage- is built across a body of water, the gates (part of the barrage) open allowing water to flow threw it along with the incoming tide. **
 * Hydrostatic- The pressure water exerts while at rest, in the barrage. **
 * <span style="color: #3366ff; font-family: 'Comic Sans MS',cursive;">Turbines- a machine that produces power in which a wheel or rotor is made to revolve by a fast- moving flow of water. **
 * <span style="color: #3366ff; font-family: 'Comic Sans MS',cursive;">Tidal- relating to, or affecting by tides. **
 * <span style="color: #3366ff; font-family: 'Comic Sans MS',cursive;">Power-energy that is produced by mechanical and electrical devices, in tidal power, the turbine is the main source of power . [1] **

​** Footnotes ** [1]= “Hydropower”. U.S Energy Information Admission. 4/11/10. ** URL **. [2]= Tidal Power: how it works. GreenpeaceUK. YouTube. 2010 [3]= Energy Sources: Tidal Power. November 3, 2009. Getaway to Adventure. URL. November 3, 2009.