The National Grid

• What is the role of Step Up Transformers in the National Grid?

  They increase the potential difference to reduce energy loss
• What percentage of electricity in the UK comes from burning fossil fuels?

  Over 50%
• What percentage of electricity in the UK comes from renewables like wind power?

  25%
• What percentage of electricity in the UK comes from nuclear power?

  About 20%
• What is the main function of the National Grid?

  To distribute electricity from power stations to homes
• How many homes does the National Grid supply electricity to in the UK?

  Around 25 million homes
• What is a significant problem in getting electricity to homes?

  Energy is lost in power cables due to resistance
• How does distance affect energy loss in power cables?

  Greater distance increases energy loss
• What is one way to reduce energy loss in electricity transmission?

  Building power stations near homes
• What happens to electricity after it passes through Step Up Transformers?

  It passes through high voltage cables
• Why can't high voltage electricity be passed directly to homes?

  The potential difference is too high
• What do Step Down Transformers do in the National Grid?

  They reduce the potential difference to around 230 volts
• What is the potential difference after electricity passes through Step Down Transformers?

  Around 230 volts
• What are the key facts about the National Grid?

  • System of Transformers and cables
  • Step Up Transformers increase potential difference
  • Reduces energy loss in transmission cables
  • Step Down Transformers reduce potential difference before homes
• What is the importance of stating "less energy is lost" instead of "less electricity is lost" in exams?

  Only "less energy is lost" earns marks