GCSE Questions: Energy Sources
Q5.
(a) Iceland is a country that generates nearly all of its electricity from renewable sources. In 2013, about 80% of Iceland's electricity was generated using hydroelectric power stations (HEP).
Describe how electricity is generated in a hydroelectric power station. Include the useful energy transfers taking place. [4 marks]
water moves (from a higher to a lower level)![](../../../../graphics/symbols/nuclides/ticksmall.png) |
transferring GPE to KE ![](../../../../graphics/symbols/nuclides/ticksmall.png) |
rotating a turbine to turn a generator![](../../../../graphics/symbols/nuclides/ticksmall.png) |
transferring KE to electrical energy![](../../../../graphics/symbols/nuclides/ticksmall.png) |
See the HEP Notes
(b) In 2013 the UK produced most of its electricity from fossil fuels.
Many people in the UK leave their televisions in 'stand by' mode when not in use, instead of switching them off. It is better for the environment if people switch off their televisions, instead of leaving them in 'stand by' mode. Explain why. [3 marks]
(TVs in stand-by) use electricity, even though it is a tiny amount that adds up when millions of devices are left on standby for a long time.
Generating electricity (from fossil fuels) produces CO2
which contributes to global warming. ![](../../../../graphics/symbols/nuclides/ticksmall.png)
(c) A scientist wrote in a newspaper: 'Appliances that do not automatically switch off when they are not being used should be banned.'
Suggest why scientists alone cannot make the decision to ban these appliances. [1 mark]
Scientists do not run our country - we are a democracy. To ban such devices it will take a Parliamentary ruling that they should be banned
(to help the country reach its 'Green' targets) - then once it was passed by Parliament it would then have to be made into a law. The Government would need to discuss the implications with manufacturers, exporters and importers of technology and disabled groups (that benefit from using remote controlled equipment).![](../../../../graphics/symbols/nuclides/ticksmall.png)
(Total 8 marks)