5 - Generating Electricity

• What are the main categories of energy sources?

  Renewable and non-renewable energy sources
• What are examples of renewable energy sources?

  • Wind
  • Hydro-electricity
  • Bio-fuel
  • Solar
  • Tides
• Why are renewable energy sources considered sustainable?

  They can be made at the same rate as used
• What is a disadvantage of renewable energy sources?

  They often provide less energy than non-renewables
• What are examples of non-renewable energy sources?

  Coal, oil, natural gas, nuclear fuel
• How are fossil fuels formed?

  They form underground over millions of years
• What happens to fossil fuels when they are used?

  They are burnt and release energy
• What is a key environmental impact of non-renewable energy sources?

  They are very damaging to the environment
• What are the steps in generating electricity from fossil fuels?

  1. Fuel is fed into the boiler
  2. Boiler heats fuel to create steam
  3. Steam is sent to the turbine
  4. Turbine drives the generator
  5. Electricity is transferred to the national grid
• What are the types of energy transfers involved in electricity generation?

  • Chemical (fuel)
  • Thermal (heat)
  • Kinetic (motion)
  • Electrostatic (electricity)
• How do bio-fuels generate electricity?

  They are burned to heat water, producing steam
• What is a disadvantage of bio-fuels?

  They cannot respond to immediate demands
• How is electricity generated from waves?

  Waves cause movement that generates electricity
• What is an advantage of wave energy?

  It is cheap to manage
• What is a disadvantage of wave energy?

  It needs a large area for energy production
• How does hydro-electricity generate electricity?

  Water passes through turbines to generate electricity
• What is an advantage of hydro-electricity?

  It produces no pollution
• What is a disadvantage of hydro-electricity?

  It requires flooding a valley
• How do fossil fuels generate electricity?

  They are heated to create steam that turns turbines
• What is an advantage of fossil fuels?

  They are cost-effective and reliable
• What is a disadvantage of fossil fuels?

  They contribute to global warming
• How do wind turbines generate electricity?

  The blades rotate in the wind to drive a generator
• What is an advantage of wind energy?

  It produces no pollution
• What is a disadvantage of wind energy?

  It can be noisy and spoil views
• How does tidal energy generate electricity?

  Tide water flows through turbines to generate electricity
• What is an advantage of tidal energy?

  It is reliable and has no fuel costs
• What is a disadvantage of tidal energy?

  It prevents free access to water by boats
• How do solar cells generate electricity?

  They generate electric currents from sunlight
• What is an advantage of solar energy?

  It is reliable in sunny areas
• What is a disadvantage of solar energy?

  It can only produce electricity during daytime
• How does geothermal energy generate electricity?

  It comes from energy released by radioactive substances
• What is an advantage of geothermal energy?

  It doesn't need sunlight to generate energy
• What is a disadvantage of geothermal energy?

  It must be built on volcanic rock
• How does nuclear energy generate electricity?

  Nuclear cells heat water to create steam
• What is an advantage of nuclear energy?

  It is reliable and 'clean'
• What is a disadvantage of nuclear energy?

  Waste products are dangerous and hard to dispose of
• What are the strengths and weaknesses of different energy sources?

  Strengths:

  • Renewable: sustainable, less damaging
  • Fossil Fuels: cost-effective, reliable
  • Wind: no pollution, minimal costs
  • Hydro: immediate response, no pollution
  • Nuclear: reliable, clean energy

  
  

  Weaknesses:

  • Renewable: less energy, weather-dependent
  • Fossil Fuels: damaging, finite resources
  • Wind: noisy, visual impact
  • Hydro: environmental impact, flooding
  • Nuclear: dangerous waste, long startup time