GCSE Physics

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GCSE Physics
2012-04-15 10:14:00
methods we use generate electricity

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  1. what are the advanatges of all renewable resources
    they are renewable
  2. what are the disadvanatges of all renewable resources
    though there are no fuel costs with renewables , the energy is dilute so that the capital cost of the generating equipment is high
  3. biomass/biofuels can be used to produce ..... ....
    thermal energy
  4. biomass a renewable energy source , is :
    • biological material derived from living or recently living organisms
    • It is similar to fossil fuels , which are derived from long dead biological material . Biofuels include waste material , ethanol , methane , wood , straw , nutshells and woodchip
  5. how do waves produce electricity
    waves use the rise and fall of water to drive turbines , the turbines are connected to generators , which transfer kinetic energy into electrical energy
  6. what are the advantages of using wave power to generate electricity
    • there is no pollution
    • they can be very useful on small remote islands
    • there are no fuel costs and running costs are minimal
    • renewable
  7. what are the disadvanatges of using wave power to generate electricity
    • they spoil the view
    • they can be a hazard to boats
    • they are fairly unreliable , since winds tend to die out when the waves drop
    • intial costs are high
    • large quantities of moving material are needed to match the energies obtained by burning fossil fuels
  8. what are the tides driven by
    the gravitational force between the earth and moon
  9. what are tidal barrages
    they are big dams built across river estuaries , with turbines in them
  10. what is a tide mill
    a device which uses the tide to create electricity
  11. what are tide mills used for
    they are used to obtain energy
  12. explain how tidal barrage would work
    • as the tide comes in water flows through the sluice gates and fills in a reservoir
    • water is trapped behind a barrage
    • as the tide flows out the water behind the barrage is at a higher level than the sea
    • this water is allowec to escape via turbines to produce electricity that is supplied to the national grid
  13. what are the advantages or tidal barrages
    • they dont cause any pollution
    • there are no fuel costs
    • the running costs are minimal
    • tidal barrages are excellent for storing energy ready for periods of peak demands
    • tidal power has the potential for generating a significant amount of energy
  14. what are the disadvantages of using tidal power to generate electricity
    • few areas are suitable
    • using energy from tides involves building barrages across river estuaries
    • tidal estuaries and mud banks would be changed upsetting the balance of wildlife living in the areas
    • tidal schemes are very expensive to set up
    • the amount of electricity produced by tidal barrages depends on the state of the tide , which varies during each day , and the height of the tide , which varies both on a monthly and yearly cycle