geothermal energy-Key text

Description

Geothermal energy is a clean, green resource with the potential to power Australia for centuries.

The world is getting hotter. This is because of the increasing concentration of greenhouse gases in the atmosphere, due mainly to our excessive burning of fossil fuels. We burn them for the energy that is needed increasingly in our daily life – to drive to school, cool ourselves on hot summer days, blow-dry our hair and listen to our music. The resulting greenhouse gases trap radiation from the sun, preventing it from escaping back into space, causing the planet’s temperature to rise. But not all of the planet’s heat comes from the Sun; some of it is within the Earth; and rather than causing global warming it could help to wean us off fossil fuels.

This heat, geothermal energy, lies in abundance beneath our feet. If the energy stored in hot rocks inside the Earth could be tapped and used instead of fossil fuels, it could help to reduce the threat of climate change.

There seems to be enough geothermal energy to keep us all ‘rocking’. The Earth’s total heat content has been calculated at 12.6 x 10 megajoules , which would meet the world’s current energy needs for several billion years. Unfortunately, most of this is inaccessible; but tapping just a fraction of it would make a substantial contribution in terms of reducing greenhouse gas emissions. Geothermal enthusiasts talk about an ‘almost limitless’ supply of energy. The challenge is tapping into it in a cost-effective way.

What is geothermal energy?

The deeper you go into the Earth the hotter it gets ( Box 1: Layers of the Earth ). Part of the heat is left over from the creation of the Earth, which started off as a hot cloud of gas and dust ...

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http://www.science.org.au/nova/116/116key.html

http://www.science.org.au/nova/116/116key.html