Energy sources

WAVE TIDAL

What is it?

Have you ever been to the beach and watched the waves continually roll in and out, pulling and pushing everything in its path? If so, you can see that the waves and tides of the ocean are very powerful and never-ending. It's these traits that make them a dependable and plentiful energy force. However, converting their energy to electricity is difficult, and not widespread.

How does it work?

Like coal and sugar cane, wave and tidal energy can be used directly to turn a turbine. It can also be channelled to push or pull air through a pipe, which turns a turbine.

Ocean waves are caused by the transfer of energy from wind as it blows across the sea. Tides are caused by the gravity pull of the moon as it rotates the earth. Turbines can be set up to catch these dependable forms of energy - the never ending up and down of waves, or the constant in and out of tides.

Advantages

Wave and tidal energy is renewable and produces no greenhouse gases making it one of the most environmentally-friendly sources of energy. It can produce electricity consistently, dependably and it is cheaper to operate and maintain.

Disadvantages

Tidal power stations do not produce energy all day as the tidal cycle is based on the rotation of the earth, gravity and its interaction with the moon and sun. Only around 20 sites worldwide have been identified as possible tidal power stations. Building a tidal power station is very expensive, and may have a negative effect on the surrounding ecosystem. Also, some wave power is very noisy (where waves are used to channel air through a pipe).

Use in Australia and around the world

There is no wave or tidal power in Australia yet. There are plans for a wave power station off the coast of Portland in Victoria. There are also a few sites being considered for tidal power stations.

The largest tidal power station in the world is in France, at the Rance Estuary. It generates 600 million kWh every year and that's enough to power 250,000 homes!