What is the impact on the environment?`Group Members:

Our final video!!!!!

We have a video for positive aspects "other" (renewability) and our intro.

We need a ending and advantages for the environment video.

Tidal Rebuttal
Student Name
Wikispace User Name
Responsible for Researching This:
Jordan Brewer
types of energy
Robert Young
why we need it
*Niki Mitchem
Is this energy source a renewable or nonrenewable source of energy? Cost of Tidal?
Kylee Williams
Is it a good energy source to use? Is there different types of tidal energy?
Chris Jaurique
CJ Bigkowski
Advantages and Disadvantages
Alicia Przybylski
What Tidel energy is? Im doing evironmental and availablility if anyone wants to do the others.

*Nick Hanlan
How it works?
Tristan Meyer
The History of tidal energy.
Tyler Howery
Ali Montemayor
Where are good areas for exploiting tidal energy?
Jake Hill
Is it safe?
Devon Morris
How much energy tidal energy gives off?


How tidal energy works

What is tidal Energy?The energy of the tides which is transformed into useful electricity and other power sources is known astidal energy or tidal power. The term tide means rise and fall of ocean and sea level due to gravitational strength from moon and rotation of earth. This is a renewable energy source which is under development and not many people know about it. Tidal energy or Tidal power is more efficient and reliable way of generating electricity as compared to wind mills and solar energy systems.http://www.renewable-solarenergy.com/tidal-energy-power.html

Tidal energy is a renewable source of electricity which does not result in the emission of gases responsible for global warming or acid rain associated with fossil fuel generated electricity. Use of tidal energy could also decrease the need for nuclear power, with its associated radiation risks. Changing tidal flows by damming a bay or estuary could, however, result in negative impacts on aquatic and shoreline ecosystems, as well as navigation and recreation.
The few studies that have been undertaken to date to identify the environmental impacts of a tidal power scheme have determined that each specific site is different and the impacts depend greatly upon local geography. Local tides changed only slightly due to the La Rance barrage, and the environmental impact has been negligible, but this may not be the case for all other sites. It has been estimated that in the Bay of Fundy, tidal power plants could decrease local tides by 15 cm. This does not seem like much when one considers that natural variations such as winds can change the level of the tides by several metros. What is the impact on the environment?

Tidals of energy
This is where i got my disadvantage info!

  • A barrage across an estuary is very expensive to build, and affects a very wide area - the environment is changed for many miles upstream and downstream. Many birds rely on the tide uncovering the mud flats so that they can feed. Fish can't migrate, unless "fish ladders" are installed.

  • Only provides power for around 10 hours each day, when the tide is actually moving in or out.

  • There are few suitable sites for tidal barrages


Same Link as Disadvantages! ABOVE!
  • Once you've built it, tidal power is free.

  • It produces no greenhouse gases or other waste.

  • It needs no fuel.

  • It produces electricity reliably.

  • Not expensive to maintain.

  • Tides are totally predictable.

  • Offshore turbines and vertical-axis turbines are not ruinously expensive to build and do not have a large environmental impact.
types of tidal energy
  • Tidal stream generator-Tidal stream generators (or TSGs) make use of the kinetic energy of moving water to power turbines, in a similar way to wind turbines that use wind to power turbines.
  • tidal barrage-Tidal barrages make use of the potential energy in the difference in height (or head) between high and low tides. Barrages are essentially damsacross the full width of a tidal estuary.
  • dynamic tidal power-Dynamic tidal power (or DTP) is a theoretical generation 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.

Why we need it.

Everything in the world runs on energy. Even our bodies use energy created by the burning of calories in order to function and produce the electricity our nerves use to control our movement.

You need energy to survive, all the basic functions of a human to survive need energy, to maintain them from not stopping. eg breathing, your heart beating, moving etc. energy is needed all over the body, if you want to move, your muscles use energy, when you carry something, you use energy, when you talk, when you look, when you do anything, your actually using energy, your body is constantly warm because its using energy to keep it that way.

Your whole body needs energy, otherwise it wouldn’t work, and we get our energy from eating foods and drinking. You might have heard of energy drinks before, there to give you more energy. The food and drink goes into our stomach and from there it is digested, absorbed, then either stored or converted into energy by chemical reactions in our body, so food is actually chemical energy, just like toys get there energy from batteries, which is electrical energy (but if you look into a battery, its actually also chemical energy in the form of pastes being converted into electrical energy)

So without energy we would not survive, nothing would survive. So where does our energy come from? The sun. The suns light is the energy that lets the plants grow, which some animals eat, where we eat those plants and animals. If there’s no light, there’s no plants, so no animals, so no us. Although now in some deep underwater places we are discovering that life can survive even when there is almost no light, but forget that for now, that’s another topic. I hope now you can see how important energy is, hoped this helped

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Is it a good energy source to use?


Tidal energy is a good source of alternative energy because it does not create any pollution of any kind. It is completely safe for our environment. It is also good because a high amount of energy can be captured using the tides and it does not cost much to turn it to electricity. As far as producing electricity goes, tidal energy is one of the cheapest kinds.

The tides also have the potential to provide a very large amount of energy so a lot of electricity can be generated from every tidal cycle. Since the tidal cycle repeats itself every 24 hours, there is a guarantee that power can be produced this way every day of the year. It is especially great since scientists can predict when the tides will occur and how much the water level will change with each tidal cycle.
The barrage that is built to capture tidal energy can help protect delicate coastal areas from storm damage, as well.
it also can protect against erosion. This is a valuable benefit since many coastlines are in danger from too much erosion caused by severe storms.
we are not using up any water when we use tidal energy. Instead, we are just catching it and releasing it so there is no danger of causing a water shortage by using this kind of energy.


external image tidal_energy_underwater_turbine.jpg
external image tida+turbine.jpg&sa=X&ei=hLQmT9bsA5SnsALv2uGMAg&ved=0CAsQ8wc&usg=AFQjCNHT8ekKdIl1IPfgQZhZkqqJrriIyw
Tidal reef design by Evans Engineering
Tidal reef design by Evans Engineering


Tidal energy is the utilization of the sun and moon's gravitational forces - as the tide is the result of their influences.
The tide moves a huge amount of water twice each day and although the tidal energy supply is reliable and plentiful, converting it into useful electrical power is not easy.
Tidal energy is considered to be a renewable source of energy since it only uses the energy from the changing of the tides instead of burning or consuming any form of energy source.
Tidal energy does not require any fuel. Tides rise and fall every day in a very consistent pattern.
Tidal energy is not on the list of sustainable energy technologies the UN agencies even though for islanders it is our best hope for large amounts of affordable clean power.
Tidal energy is perceived as having the potential to provide a reliable source of green energy because it is predictable and guaranteed, unlike wind turbines, which are dependent on the weather.
Tidal energy has an efficiency of 80% in converting the potential energy of the water into electricity.
Tidal power changes the sedimentation and turbidity (how clear the water is) of the water system.
Tidal power can provide secondary benefits such as bridges and roads, which are built over the tidal generators.

Different Types of Tidal Energy:

Tidal stream systems use the kinetic energy of the moving water to power turbines.
Tidal stream systems can be placed where there are strong, fast currents. Good locations can be found at the entrances to bays and rivers and between islands or other land masses where the currents become concentrated forces. There are a number of designs for tidal stream systems.
Barrages use the potential energy in the difference between the height of the high and low tides.
Barrage turbines generate electricity as the tide flows in and out of the bay, river or estuary. Barrage systems involve high civil infrastructure costs and there are potential environmental issues to address related to altering the ecosystem.

This is where i got my info on environmental.!
Tidal energy is a good source of alternative energy because it does not create any pollution of any kind. It is completely safe for our environment. It is also good because a high amount of energy can be captured using the tides and it does not cost much to turn it to electricity. As far as producing electricity goes, tidal energy is one of the cheapest kinds. We know that our planet is in danger from too much pollution. Most of the pollution is created by burning coal and oil to make electricity. When we burn these fossil fuels, dangerous gases called greenhouse gases are released into the atmosphere. These greenhouse gases are causing global warming, which is a danger to all life on Earth if we don’t get it under control. Because of this, scientists and other people are working hard to find ways to use new energy sources that won’t hurt our planet. These new energy sources are called alternative energy sources. One alternative energy source that is getting a lot of attention from scientists is tidal energy, or energy made from the ocean tides.

As you probably already know, tidal energy is using the shifting of the ocean's tides to generate some form of energy. This was done in 900 A.D. by using naturally-occurring basins close to the ocean, and building a barrage (or dam) across the opening. The basin would fill when the ocean's tide rises, and would empty when the tide lowered. Usually when the tide would come in to the basin it would spin one water wheel, and spin a different one when it drained back into the ocean.

These early water wheels were not used to generate electricity (as they didn't know about it at the time), but instead would grind grains and corn into flour. This saved the farmers a lot of laborious hard work, so it changed the farming industry in a very positive way.

The first commercial-scale modern tidal energy plant was built in 1966. Near St. Malo, France, it is currently the largest and most energyful tidal energy plant in the world. Although other, smaller plants have been built, this one still reigns supreme as the biggest.
As you probably guessed, water wheels and paddlewheels are not the devices used in this plant! Modern tidal energy plants instead use highly efficient bulb-type hydroelectric turbine/generator sets. The tidal energy plant at St Malo uses twenty four 10 megawatt turbine generator sets. These were installed in 1965, and this plant has been functioning non-stop ever since then.
The plant at St. Malo was the only one used for a long time, until 1982 when a tidal energy plant was built at Annapolis Royale, Nova Scotia, Canada. This plant was primarily set up to demonstrate the functioning of a new turbine built by GE in Canada and invented by Escher-Wyss of Switzerland. Although there were a few issues early on with this plant, it has been functioning flawlessly since its earlier days.

The largest tidal barrage proposal was to be between Wales and England by damming the Severn Estuary. If this effort had been successful, experts estimated that roughly 12% of the United Kingdom's energy needs would have been generated from this one source. This proposal was shelved in 1987, and never came to fruition due to economic problems and pushback from environmentalist groups.


The Generation of Tidal Energy
Tidal power is extracted 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. The magnitude and character of this motion reflects the changing positions of the Moon and Sun relative to the Earth, the effects of earths rotation, and local geography of the seafloor and coastlines.
Tidal power is the only technology that draws on energy inherent in the orbital characteristics of the EarthMoon 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, conventionalhydroelectric, wind, biofuel, wave and solar 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 of residual heat fromplanetary accretion (about 20%) and heat produced through radioactive waves (80%).


picture of tidal system energy

tidal system energy

How much energy does tidal energy give off?
The amount of electricity produced by tidal power depends entirely on the size of the tidal power station. Other factors such as the difference in height between low and high tides or if the area is semidiurnal (two high and two low tides per day) or diurnal (one high and low tide per day)
one source says the Severn Barrage would provide over 8,000 Megawatts of power (that's over 12 nuclear power station's worth), another says it would be equivalent to 3 nuclear power stations. http://www.darvill.clara.net/altenerg/tidal.htm animation pic: http://technologystudent.com/images5/tidal1.gif
Video: http://www.youtube.com/watch?v=4Iq-h4ShZ8s
There is a proposed project with name Severn Barrage, in Wales. This project has been proposed in past but it never got initiated. This project estimated cost is about £15 million. It is also stated that it will produce energy which is massive 8000 MW, which is more than 12 nuclear worth of power station, some proposals have mentioned that it will provide 2500 MG worth of power, there is huge difference between power generation estimation and it is not appropriate to risk £15 millions worth of money. This is the main reason why this project is yet start. http://www.solarpowernotes.com/renewable-energy/tidal-energy/tidal-energy.html
pic1: http://www.oceanpowermagazine.net/wp-content/uploads/2010/11/MarineTurbines.jpg
pic 2 :http://media-3.web.britannica.com/eb-media/49/121649-004-16E15661.gif
Is tidal Energy safe?
This says that tidal energy doesn't give off any pollutants and is completely safe.
There are a few environmental concerns regarding tidal energy. Firstly, as the water in the basin and sea hardly is exchanged, the salinity of the basin decreases, which would affect the ecosystem. Also, when the water is not exchanged, the turbidity (amount of matter in suspension in water) decreases, thus letting much sunlight get into the water, which would thus encourage phytoplankton growth, upsetting the ecosystem once again.

Is it Renewable?

Tidal energy is renewable. The tides will continue to ebb and flow, and the energy is there for the taking.
No matter what use we may make of the tides, we do not use them up. The tides will continue to ebb and flow, driven by gravitational forces.
Notice how it says that people have been using the tidal energy for centuries, and that the waves can be predicted years in advance, showing that it is reliable and that the waves will never leave. Also it says it is renewable and sustainable.

Table 1 – Capital cost breakdown of MCT pilot plant

in %
Power Conversion System
Structural Steel Elements
Subsea Cable Cost
Turbine Installation
Subsea Cable Installation
Onshore Electric Grid Interconnection

Total Installed Cost

I thought the video below was interesting, it shows a real life underwater turbine, so we have something that is real, not animated. Compfight Video.


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This shows kind of what a turbine looks like. This is what produces the electricity.