Generating and Transfering Energy
Designed by Dr T. Marlow
a) In some power stations an energy source is use 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.
b) Water and wind can be used to drive turbines directly.
c) Electricity can be produced directly from the Sun’s radiation.
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.
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.
f) Using different energy resources has different effects on the environment. These effects include:
■ the release of substances into the atmosphere
■ the production of waste materials
■ noise and visual pollution
■ the destruction of wildlife habitats.
The National Grid
a) Electricity is distributed from power stations to consumers along the National Grid.
b) For a given power, increasing the voltage reduces the current required and this reduces the energy losses in the cables.
c) The uses of step-up and step-down transformers in the National Grid.