energy demands

• Every person, animal and device transfers energy
• Much of that energy is supplied by electricity, which must be generated from other energy stores
• Some of these energy stores are renewable but most are non-renewable
• Energy


  The capacity for doing work
• Energy store


  The different ways in which energy can be stored, including chemical, kinetic, gravitational potential, elastic potential and thermal stores
• Energy resource


  Useful supply or store of energy
• Major energy resources available to produce electricity

  • Fossil fuels
  • Nuclear fuel
  • Bio-fuel
  • Wind
  • Hydroelectricity
  • Geothermal
  • Tidal
  • Water waves
  • Sun
• Ultimately, all the energy on Earth originally comes from the Sun but has been stored as different energy resources
• Energy needs


  • Homes - for cooking, heating and running appliances
  • Public services, eg schools and hospitals - running machinery and warming rooms
  • Factories and farms - operating heavy-duty machines and production chains
  • Transport - buses, trains, cars and boats all need a fuel source and some trains and trams connect to an electricity supply
• Producing and distributing electricity can cause damage to the environment
• Releasing energy from some stores causes pollution and harmful waste products
• Burning fossil fuels releases carbon dioxide, adding to the greenhouse effect, and sulphur dioxide which causes acid rain
• Industrial Revolution


  The process that transformed manufacturing from handmade to machine-made, mass-produced goods using water, steam and coal power transported by canal, rail and steamship. Britain was the first country to have an Industrial Revolution
• During the Industrial Revolution, advances in automation and transport caused a significant increase in the amount of fossil fuels extracted and burnt
• In the 20th century, electricity became a convenient way of distributing energy
• Electricity powered a wide range of devices and applications such as lighting, heating, computing technologies and operating machinery
• Demand for energy varies with the time of year and the time of day
• Most of the electricity generated globally is still produced by fossil fuels
• This is partly due to the high power output fossil fuels give compared to other energy resources, like wind and water waves
• This is partly due to the existing infrastructure for extracting, transporting and processing fossil fuels - this makes fossil fuels cheaper than setting up new alternatives
• Renewable energy resources


  Energy sources that are replenished and not exhausted, eg solar power
• In some developed countries, nuclear power stations are a growing form of electricity generation
• Nuclear fuel can release large amounts of energy compared to fossil fuels and does not emit carbon dioxide
• However, the radioactive waste that is produced is difficult to store and dispose of
• Other factors that could influence governments' decisions about the use of energy resources are political and economic pressures
• Countries where the economy is heavily based on extracting and exporting oil, have a strong interest in fossil fuels to be largely used in electricity generation
• In order to compete with more developed countries, growing countries like China need a large power output to keep growing their industry
• Energy resources


  • Fossil fuels (oil, coal and natural gases)
  • Nuclear fuels
  • Bio-fuel
  • Wind
  • Hydroelectricity
  • Geothermal
  • Tides
  • Sun
  • Water waves
• This means they are likely to continue using fossil fuels and developing the use of nuclear power, alongside increasing supply from renewable sources of energy
• Renewable energy resource


  A resource that is being (or can be) replenished as it is used, either by human action or natural processes
• Non-renewable energy resource


  A resource with a finite amount that will eventually run out when all reserves have been used up
• Features of energy resources

  • Energy store
  • Renewable?
  • Uses
  • Power output
  • Environmental impact
• Fossil fuels (oil, coal and natural gases) are a non-renewable energy resource used for transport, heating, and electricity generation. They have a high power output but release CO2 which causes global warming.
• Nuclear fuels are a non-renewable energy resource used for electricity generation. They have a very high power output but produce radioactive waste that needs to be disposed of safely.
• Bio-fuel is a renewable energy resource used for transport, heating, and electricity generation. It has a medium power output but is 'carbon neutral' so has a low environmental impact.
• Wind is a renewable energy resource used for electricity generation. It has a very low power output but takes up large areas that could be used for farming, and some people say windmills spoil the view.
• Hydroelectricity is a renewable energy resource used for electricity generation. It has a medium power output but local habitats are affected by the large areas that need to be flooded to build dams.
• Geothermal energy is a renewable energy resource used for electricity generation and heating. It has a medium power output and a very low environmental impact.
• Tidal energy is a renewable energy resource used for electricity generation. It has a potentially very high power output but is hard to harness, and tidal barrages can block sewage which needs to go out to sea.
• Solar energy from the sun is a renewable energy resource used for electricity generation and heating. Its power output is dependent on the weather and only available during daylight, but it has very little environmental impact.