Group members :

Perian Bogdan

Ghenea Madalin

Tihu Mircea

This is the only form This is the only form of energy whose of energy whose source is the moon. source is the moon. Some other energy Some other energy sources, nuclear power sources, nuclear power and geothermal and geothermal energy for instance, energy for instance, have the Earth as their have the Earth as their source. The remainder, source. The remainder, fossil fuels, wind fossil fuels, wind energy, biofuels, solar energy, biofuels, solar energy, etc. have the energy, etc. have the Sun as their source, Sun as their source, directly or indirectly.directly or indirectly.

The tidal power is generated by The tidal power is generated by the gravitational pull of the Moon the gravitational pull of the Moon on water. Due to these on water. Due to these gravitational forces the water gravitational forces the water level follows a periodic high and level follows a periodic high and low. The height of the tide low. The height of the tide produced at a given location is produced at a given location is the result of the changing the result of the changing positions of the Moon and Sun positions of the Moon and Sun relative to the Earth coupled with relative to the Earth coupled with the effects of Earth rotation and the effects of Earth rotation and the local shape of the sea floor.the local shape of the sea floor.

The tidal energy generator uses The tidal energy generator uses this phenomenon to generate this phenomenon to generate energy. The higher the height of energy. The higher the height of the tide the more promising it is the tide the more promising it is to harness tidal energy.to harness tidal energy.

Tidal power typesTidal power typesTidal power can be classified into Tidal power can be classified into

two main types:two main types:• Tidal stream systems make Tidal stream systems make

use of the kinetic energy from use of the kinetic energy from the moving water currents to the moving water currents to power turbines, in a similar power turbines, in a similar way to wind mills use moving way to wind mills use moving air. This method is gaining in air. This method is gaining in popularity because of the popularity because of the lower cost and lower lower cost and lower ecological impact. ecological impact.

• Barrages make use of the Barrages make use of the potential energy from the potential energy from the difference in height between difference in height between high and low tides. Barrages high and low tides. Barrages suffer from the problems of suffer from the problems of very high civil infrastructure very high civil infrastructure costs, few viable sites globally costs, few viable sites globally and environmental issues. and environmental issues.

Modern advances in turbine technology may Modern advances in turbine technology may eventually see large amounts of power generated from eventually see large amounts of power generated from the ocean especially tidal currents using the tidal stream the ocean especially tidal currents using the tidal stream designs. designs.

Tidal stream turbines may be arrayed in high velocity Tidal stream turbines may be arrayed in high velocity areas where natural flows are concentrated such as the areas where natural flows are concentrated such as the west coast of Canada, the Strait of Gibraltar, the west coast of Canada, the Strait of Gibraltar, the Bosporus, and numerous sites in south east Asia and Bosporus, and numerous sites in south east Asia and Australia. Such flows occur almost anywhere where Australia. Such flows occur almost anywhere where there are entrances to bays and rivers, or between land there are entrances to bays and rivers, or between land masses where water currents are concentrated.masses where water currents are concentrated.

AdvantagesAdvantages

Reduced greenhouse gas emissions by tidal powerReduced greenhouse gas emissions by tidal power Easy to predictEasy to predict Improved transportation because of the development of Improved transportation because of the development of

traffic or rail bridges across estuariestraffic or rail bridges across estuaries Not many places have dramatic enough tide change to Not many places have dramatic enough tide change to

support a tidal power plantsupport a tidal power plant Reduces dependence on fossil fuels Reduces dependence on fossil fuels Is a reliable, dependable sourceIs a reliable, dependable source RenewableRenewable Produces no pollutionProduces no pollution

DisadvantagesDisadvantages

Effect on plants and animals which live near tidal Effect on plants and animals which live near tidal stations stations

Very little is known about the full effect of tidal power Very little is known about the full effect of tidal power plants on the local environment because so few have plants on the local environment because so few have been built been built

There are times of low power and high power because There are times of low power and high power because the tides have high and low periods the tides have high and low periods

Few places where tides are actually strong enough to Few places where tides are actually strong enough to produce amount able energy produce amount able energy

Could damage/destroy animals habitats Could damage/destroy animals habitats Expensive construction of power plants Expensive construction of power plants Tidal fences can block paths for migrating fish Tidal fences can block paths for migrating fish

The The Rance tidal Rance tidal power plantpower plant is the is the world's first electrical world's first electrical generating station generating station powered by tidal energy. powered by tidal energy. It is located on the It is located on the estuary of the Rance estuary of the Rance River, in Bretagne, River, in Bretagne, France. It is operated by France. It is operated by Électricité de France Électricité de France (EDF).(EDF).

Rance Tidal power plantRance Tidal power plant

The construction The construction necessitated draining the necessitated draining the area where the plant was to area where the plant was to be built, which required be built, which required construction of two dams; an construction of two dams; an effort which took two years. effort which took two years. Construction of the plant Construction of the plant proper commenced 20 July proper commenced 20 July 1963, while the Rance was 1963, while the Rance was entirely blocked by the two entirely blocked by the two dams.dams.

The construction took The construction took three years and was three years and was completed in 1966. Charles completed in 1966. Charles de Gaulle, then President of de Gaulle, then President of France, inaugurated the France, inaugurated the plant on 26 November of the plant on 26 November of the same year. same year.

The idea of constructing a tidal power plant on the The idea of constructing a tidal power plant on the Rance dates to Gerard Boisnoer in 1921. Rance dates to Gerard Boisnoer in 1921. The site was attractive The site was attractive because there is a large because there is a large average range between average range between low and high tide levels low and high tide levels (8 metres, with a (8 metres, with a maximum equinoctial maximum equinoctial range of 13.5 metres). range of 13.5 metres). Nevertheless, work did Nevertheless, work did not actually not actually commmence until 1961.commmence until 1961.