The National Grid

• What should you be able to describe by the end of the video?

  How electricity is distributed by 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?

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

  Around 20%
• What is the main challenge 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 leads to greater energy loss
• Why don't people want to live near power stations?

  They are concerned about safety and pollution
• What do step-up transformers do to the potential difference?

  They increase it to several hundred thousand volts
• Why is a high potential difference important in the National Grid?

  It reduces energy loss in transmission cables
• What happens to electricity after it passes through high-voltage cables?

  It goes through step-down transformers
• What do step-down transformers do to the potential difference?

  They reduce it to around 230 volts
• What is the final potential difference of electricity before it enters homes?

  Around 230 volts
• What are the key components of the National Grid?

  • System of transformers
  • High-voltage cables
  • Step-up transformers
  • Step-down transformers
• What are the roles of step-up and step-down transformers in the National Grid?

  • Step-up transformers: Increase potential difference to reduce energy loss
  • Step-down transformers: Reduce potential difference for safe home use
• What should you remember to say about energy loss in exams?

  Less energy is lost, not less electricity
• Where can you find more questions on the National Grid?

  In the revision workbook
• What is the main purpose of the National Grid?

  To distribute electricity from power stations to homes