The national Grid

• Electricity is generated in the UK from various sources: over 50% from burning fossil fuels, 25% from renewables such as wind power, and around 20% from nuclear power, with the remainder imported from Europe
• The electricity has to get from the power stations to around 25 million homes in the UK, and this is done by the National Grid
• National Grid

  A system of transformers and high-voltage cables that connects the power stations to the homes
• Energy is always lost in the power cables due to the resistance of the wires, and the greater the distance between the power station and the homes, the greater the energy loss
• Electricity distribution by the National Grid

  1. Passes through step-up transformers to increase the potential difference to several hundred thousand volts

  2. Passes through high-voltage cables

  3. Passes through step-down transformers to reduce the potential difference to around 230 volts

  4. Passed into homes
• Step-up transformers


  • Increase the potential difference, which reduces energy loss in the transmission cables
• Step-down transformers


  • Reduce the potential difference before the electricity passes to homes