The National Grid

• What percentage of electricity in the UK comes from burning fossil fuels?

  Over 50%
• What is the contribution of renewables like wind power to the UK's electricity generation?

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

  Around 20%
• What is the role of the National Grid?

  To distribute electricity from power stations to homes
• What is a significant problem in getting electricity to homes?

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

  The greater the distance, the greater the energy loss
• Why do people not want to live near power stations?

  People generally prefer not to live near them
• What is one way to reduce energy loss in electricity distribution?

  Building power stations near to homes
• What is the function of step-up transformers in the National Grid?

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

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

  It passes through step-down transformers
• What do step-down transformers do in the National Grid?

  They reduce the potential difference 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
• 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 before electricity reaches homes
• What should you avoid saying when discussing energy loss in the National Grid?

  Do not say less electricity is lost