National & Global Energy Sources

• Electricity generation


  1. Turbine is turned

  2. Turns a generator

  3. Generates electricity
• Hydroelectric power


  1. Water used to turn turbines

  2. Energy in kinetic store of flowing water transferred to kinetic store of turbine

  3. Then to kinetic store of generator

  4. Transferred electrically to National Grid
• Hydroelectric dam


  Transfers energy from gravitational potential energy store of water to kinetic energy store mechanically to turn a turbine
• Fossil fuel power


  1. Fossil fuels combusted to heat water

  2. Steam produced used to turn turbines

  3. Energy from chemical store of fuel transferred to thermal store of water

  4. Then to kinetic store of turbine

  5. Then to kinetic store of generator

  6. Transferred electrically to National Grid
• Nuclear power


  1. Nuclear store of fuel

  2. Transferred to thermal store of water

  3. Then to kinetic store of turbine

  4. Then to kinetic store of generator
• Geothermal power


  1. Water pumped down to hot rocks

  2. Returns as steam through fissure

  3. Cold water heated by rocks and returned as hot water or steam to turn turbines
• Renewable energy resource


  An energy source that is replenished at a faster rate than the rate at which it is being used
• Renewable energy resources


  • Solar energy
  • Wind
  • Bio-fuel
  • Hydroelectricity
  • Geothermal
  • Tidal
• Non-renewable energy resources


  • Fossil Fuels (coal, oil and natural gas)
  • Nuclear fuel
• Main uses of energy resources


  • Transport
  • Electricity generation
  • Heating
• Transport


  • Majority of vehicles powered by petroleum products (petrol, diesel, kerosene)
  • Growing number of vehicles powered by electricity
  • Vehicles can also be powered by biofuel
• Electricity generation


  • Electricity plays a bigger role in people's lives than ever before
  • Demand for electricity is extremely high
  • Combination of all energy resources needed to keep up with demand
  • Majority (84%) of world's energy still produced by non-renewable, carbon-emitting sources
  • Negative impact on environment
  • Scientists working to develop more efficient ways to produce electricity using more carbon-neutral energy resources
• Heating


  • Most homes in cold countries fitted with central heating systems using natural gas
  • Natural gas is a non-renewable energy resource
  • In geologically active countries like Iceland, homes can be heated using geothermal energy
• Fossil fuels (oil, coal and natural gases)


  • Chemical
  • Non-renewable
  • Transport, heating, electricity generation
  • High
  • Releases CO2 (causes global warming)
• Nuclear fuels


  • Nuclear
  • Non-renewable
  • Electricity generation
  • Very high
  • Radioactive waste (needs to be disposed of safely)
• Bio-fuel


  • Chemical
  • Renewable
  • Transport, heating, electricity generation
  • Medium
  • 'Carbon neutral', so low impact
• Wind


  • Kinetic
  • Renewable
  • Electricity generation
  • Very low
  • Takes up large areas that could be used for farming, some people say windmills spoil the view
• Hydroelectricity


  • Gravitational potential
  • Renewable
  • Electricity generation
  • Medium
  • Local habitats are affected by the large areas that need to be flooded to build dams
• Geothermal


  • Internal (thermal)
  • Renewable
  • Electricity generation, heating
  • Medium
  • Very low
• Tides


  • Kinetic
  • Renewable
  • Electricity generation
  • Potentially very high, but hard to harness
  • Tidal barrages can block sewage which needs to go out to sea
• Sun


  • Nuclear
  • Renewable
  • Electricity generation, heating
  • Dependent on the weather and only available during daylight
  • Very little
• Water waves


  • Kinetic
  • Renewable
  • Electricity generation
  • Low
  • Very low
• Comparing Energy Resources

  • Each energy resource has various advantages and disadvantages associated with it
  • A renewable energy resource is one that is replenished at a faster rate than the rate at which it is being used
  • As a result of this, renewable energy resources will not run out
  • A reliable energy resource is one that can produce energy at any time
  • Non-reliable resources can only produce energy some of the time (e.g. when it’s windy)
  • The table below shows a comparison of the advantages and disadvantages of the different energy resources:
• Energy Resources


  • Fossil fuels
  • Nuclear power
  • Wind turbines
  • Wave generators
  • Tidal generators
  • Hydroelectric power stations
  • Solar cells
• Fossil fuels


  • Reliable
  • Create pollution and will run out
• Nuclear power


  • Reliable
  • Will run out and produce dangerous waste that is hard to dispose of
• Wind turbines


  • Clean and cheap to run
  • Expensive to set up and wind does not always blow
• Wave generators


  • Clean and cheap to run and Scotland has a lot of coastline
  • Expensive to set up
• Tidal generators


  • Clean and cheap to run and produce a lot of electricity once running
  • Very expensive to set up and could be hazardous to local wildlife
• Hydroelectric power stations


  • Clean and cheap to run
  • Expensive to set up and output could be affected by drought
• Solar cells


  • Clean and cheap to run
  • Not always sunny and output does not always outweigh initial cost to set up
• The Greenhouse Effect


  Global warming is a problem caused by the increased concentration and effect of greenhouse gases, mainly methane and carbon dioxide
• The process of global warming

  1. The Sun emits rays that enter the Earth's atmosphere

  2. The infrared radiation is emitted back from the Earth's surface

  3. Some infrared radiation is reflected back out into Space

  4. Some infrared radiation is absorbed by Greenhouse gases and becomes trapped within the Earth's atmosphere, causing the Earth's average temperature to rise as a result
• Consequences of global warming


  • Climate change due to the increase in Earth's temperature
  • Sea levels will rise as glaciers melt because of high temperatures, causing flooding in low-lying countries
  • Extinction of species due to the destruction of natural habitats
  • Migration of species (including humans) as they will move to areas that are more habitable (with no droughts or recurring wildfires)
  • Spread of diseases caused by warmer climate
  • Loss of habitat due to climate change (animals that live on glaciers)