National grid

• What is the national grid?

  A giant network of transformers and wires
• Where does most electricity in the UK come from?

  Power stations
• How do power stations generate electricity?

  By generating heat and converting it to electrical energy
• What factors influence how much electricity power stations generate?

  Electricity demand
• When does electricity demand generally peak?

  Late afternoon and evening
• Why do power stations need spare capacity?

  To cope with surges in demand
• What happens when high current flows through a wire?

  It generates lots of heat due to resistance
• How can we achieve high power in electricity transmission?

  By using high voltage and low current
• What do we use to increase voltage for electricity transmission?

  Step up transformers
• What voltage do step up transformers increase electricity to?

  Around 400,000 volts
• What do the wires in the national grid transmit electricity between?

  Huge pylons
• Why must voltage be reduced before reaching homes?

  High voltages are dangerous and can damage appliances
• What do step down transformers do?

  Lower voltage to around 230 volts
• What is the process of electricity transmission through the national grid?

  • Electricity generated in power stations
  • Step up transformers increase voltage to 400,000 volts
  • Wires transmit electricity across the country
  • Step down transformers lower voltage to 230 volts for safety
• What should you do if you found the video useful?

  Like and subscribe
• What are the key components of the national grid?

  • Transformers
  • Wires
  • Pylons
  • Step up and step down transformers