By: Jillian Marsh Alexis Golden Brandon Golden Alex Comins Tidal/Wave By: Jillian Marsh Alexis Golden Brandon Golden Alex Comins

What is it? Also known as tidal energy. Tidal energy is produced by the surge of ocean waters during the rise and fall of tides, and is a renewable source of energy. Mainly electricity Engineers developed a procedure in which they could use tidal movement to generate electricity in areas with significant amounts of tidal range (the difference in area between high tides and low tides)

How do tidal power plants work? There are currently 3 different ways to get tidal energy: tidal streams, barrages, and tidal lagoons.

Turbines For most tidal generators, turbines are placed in tidal streams. A tidal steam is a fast flowing body of water created by tides. The turbine takes energy from the rushing water or waves. (The energy from tidal power is much better than wind because water is much denser than air)

This way of generating electricity uses a large dam called a barrage and can be built across tidal rivers, bays and estuaries The barrage opens as the tide rises. At high tide, the barrage is closed, and creates a pool, or tidal lagoon. The water is then released through the barrage's turbines, creating energy at a rate that can be controlled by engineers. Barrage

Tidal lagoons ***There however are no working examples of tidal lagoons. China is constructing a tidal lagoon power plant at the Yalu River, near its border with North Korea. A private company is also planning a small tidal lagoon power plant in Swansea Bay, Wales. A tidal lagoon is a body of ocean water that is partly enclosed by a natural or manmade barrier. Tidal lagoons might also be estuaries and have freshwater emptying into them. Tidal lagoons function much like a barrage would but unlike barrages they can be constructed along a coastline A tidal lagoon power plant would generate continuous power. The turbines work as the lagoon is filling and emptying. The lagoons can be constructed with natural materials like rock and would appear as a sea wall at low tide but would be submerged at high tide.

Costs To set up a tidal power station, it could cost a lot depending on how large the station is. Example: A 8,000 MW tidal power and barrage system costs about $15 billion. A 2,200 MW costs about $3 billion.

The 2 largest power sites in operation currently are found in France and Canada. In France the 240 MW bulb turbine powers a city of 300,000 individuals. In Canada the Bay of Fundy plant generates 16 MW powering an estimated 4500 houses in the area.

How many tidal power plants does NY/US have? New York state has approximately 300 hydroelectric stations. The United States as a whole has approximately 2,000 hydroelectric stations. In New York State 17% of the electricity is generated by tidal power. In the United States, 6 to 7 percent of the electricity is generated by tidal power.

Pros Renewable: -Tidal energy is a renewable energy source Green: -Tidal energy is environmentally friendly energy source. Predictable: -Tidal currents are very predictable and stable. It produces a steady, reliable stream of electricity. High and low tides are developed in known cycles which make it easier to construct the systems.

Pros Effective at low speeds: -Water has a 1,000 times higher density then air does. This makes it possible to generate electricity at low speeds. Long Lifespans: -They can spend a long time generating electricity without being replaced.

Cons Environmental Effects: Close to land: The effects of tidal power plants have on the environment are not completely known yet. The only thing known for sure is that is generates green electricity. Close to land: Tidal wave power plants need to be built close to lands.

Cons Continued… Expensive: Since tidal energy is relativity new technology it is currently expensive, but with better technology it should be cheaper by 2020.