P1.4.1 |
Generating electricity |
a) In some power stations an energy source is used to heat water. The steam produced drives a turbine that is coupled to an electrical generator. Energy sources include:
■ the fossil fuels (coal, oil and gas) which are burned to heat water or air
■ uranium and plutonium, when energy from nuclear fission is used to heat water
■ biofuels that can be burned to heat water. |
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b) Water (HEP, wave, tidal) and wind can be used to drive turbines directly. |
Energy sources used in this way include, but are not limited to, wind, waves, tides and the falling of water in hydroelectric schemes. |
| c) Electricity can be produced directly from the Sun's radiation. |
Candidates should know that solar cells can be used to generate electricity and should be able to describe the advantages and disadvantages of their use. |
| d) In some volcanic areas hot water and steam rise to the surface. The steam can be tapped and used to drive turbines. This is known as geothermal energy. |
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| e) Small-scale production of electricity may be useful in some areas and for some uses, eg hydroelectricity in remote areas and solar cells for roadside signs. |
Candidates should understand that while small-scale production can be locally useful it is sometimes uneconomic to connect such generation to the National Grid. |
Using different energy resources has different effects on the environment.
These effects include:
■ the release of substances into the atmosphere (polluting gases and those that cause global warming)
■ the production of waste materials
■ noise and visual pollution
■ the destruction of wildlife habitats. |
Candidates should understand that carbon capture and storage is a rapidly evolving technology.
To prevent carbon dioxide building up in the atmosphere we can catch and store it.
Some of the best natural containers are old oil and gas fields, such as those under the North Sea. |
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