Tidal Energy

What is Tidal Energy?
Everyday the tide at the seaside goes in and out - twice. Tides are caused by the pull of gravity on the moon and the Sun. The going out and coming in of the tides creates a powerful flow of water which can be used to generate electricity.

You may have noticed when you are on the beach that the tides are different each time they come in to the shore. The difference in the tides is due to the pull of the moon on the Earth.

How can we make use of tidal energy?

• A tidal power station - (which is also sometimes known as a tidal barrage) is a giant dam that is built across a bay or estuary on the coast.
• Along the length of the tidal power station, turbines spin as the tide comes in and out. As the tide comes in the barrage holds the sea back making the level of water on each side different.
• A set of gates are then opened allowing the water to rush through and turn a turbine which generates electricity.
• Every time the tide comes in and goes out electricity can be generated.

Advantages of tidal energy

• Tides are more reliable than the wind, waves or solar power so the amount of electricity can be predicted quite accurately.
• Tidal energy is renewable energy – no fuel is used.

Disadvantages of tidal energy

• There are only a few good sites for tidal power stations.
• Tidal power stations make it difficult for ships to pass through estuaries.
• Tidal power stations can have an affect on animals which live in the sea.