Nota Terkini

Friday, July 10, 2009

Water Waves

Burning coal, oil and gas for fuel causes lots of pollution. Now scientists think the sea might give us clean power.

When breezes touch the surface of the ocean, waves appear. Mild winds produce low waves. But big winds can create waves that are 18m high - that's as tall as a six storey building.

We power cars, factories, air conditioning and other systems by burning fossil fuels. But burning oil, gas and coal causes pollution. Fossil fuels are also very expensive.

In the 1970s, scientists began to look for renewable, non-polluting energy sources. Today, there are several methods to harvest energy from the sea.

The Oscillating Water Column System (OWS) gathers the energy of waves breaking onto the shore. Engineers arrange a series of hollow pipes just under the water line. When the waves run in and out of the pipes, they create a stream of moving air. This movement turns a turbine and generates electricity.

The buoyant moored system is a type of rafr that floats on the ocean's surface. When waves move it up and down, the energy of this movement turns turbines to create electricity.

Wave farms do have some drawbacks. First, these projects take up a lot of space. Also, they need to be built with the strongest materials to survive corrosion and storms. This can be expensive.

But as fuel prices increase, more wave farms are built. Scotland and Portugal now have commercial wave farms. May be, we may have one in Malaysia soon too.

** How Wave Energy Works at science.howstuffworks.com/wave-energy.htm has great diagrams that show oscillating water column systems and buoyant moored systems. The also explain pros and cons of wave farms in detail.


Information:
  • The top of a wave is called the crest or peak.
  • The lowest part or hollow of a wave is called the trough.
  • No two ocean waves are exactly alike.
  • Tsunamis are not caused by wind but by geological changes like earthquakes.

Joke & Riddle
  1. What lies at the bottom of the sea and shakes?
    A nervous wreck.

  2. What has no beginning, end or middle, and touches every continent?
    The ocean.

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