Earth and beyond

Earth's energy resources

non-renewable energy sources

renewable energy sources

sources of energy in the world

unusual sources of energy

measuring work and energy

the greenhouse effect

nuclear power

trapping the Sun's energy

using solar cells

Sun and climate

unusual sources of energy

Sometimes we have been able to use energy from the most unusual sources. Here are a few examples including molten rock, chicken poo and sugar.

Geothermal energy - what's that?

'Geo' is the Greek for Earth and 'therme' is the Greek for heat. So geothermal energy is heat from inside the Earth. Deep inside the Earth the rock is very hot and molten. Sometimes we see this as lava when it erupts through the surface in volcanoes. However, we don't need access to a volcano to be able to use geothermal energy. In some places where the ground is hot we can use heat-pumps to transfer the energy to the surface. These work in a similar way to your home refrigerator, only in reverse. Sometimes when water is next to hot ground this can produce steam, which can be used to heat buildings directly or to drive turbines for electricity generation.

Image of steam pipelines, Wairakei Power Station

Because it is in an area of the world with a lot of geological activity, geothermal energy is easily available in New Zealand and it gets about 20% of its energy from geothermal sources.

What type of hens produce electricty? - Battery hens - that's a fowl joke!

Power from poultry poo?

It's true! A company called Fibrowatt built the world's first power station, which generates electricity using poultry poo as a fuel. The 12.7 megawatt power station, which is in Suffolk , generates enough electricity for 29,000 homes.

Cars powered by sugar

In the 1980's, Brazil tried to develop a new fuel for cars from sugar. They fermented the sugar cane to produce ethanol (just like grapes are fermented to produce wine) and managed to get three quarters of all their new cars using ethanol instead of regular petrol made from oil. Even nowadays, petrol sold in Brazil contains 26% ethanol.

Image of a factory in a field
A power station which is fuelled by poultry poo at Eye in Suffolk.

Image of Toyotas hydrogen fuelled concept car Cars fuelled by hydrogen.

Petrol is made from oil, which is a non-renewable source and so scientists and engineers are developing alternative fuel for cars. One possible solution is the hydrogen fuel cell. This works a bit like a battery. Hydrogen gas (H) is combined with oxygen (O₂) molecules to form water (H₂O) and chemical energy is transformed into electrical energy. It sounds simple but the technology is complicated, so it'll be a while before you're driving a car like this Toyota test version.



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