Generation, Transmission & Distribution of Electricity

Electricity Supply Overview

  • Understanding where electricity comes from and its journey to homes and businesses involves multiple stages.

Stage 1: Generation – How Electricity is Produced

  • Sources of Electricity:

    • Renewable Energy Sources:

      • Wind

      • Solar

      • Hydropower

      • Bioenergy

    • Non-renewable Energy Sources:

      • Coal

      • Fossil Fuels

      • Nuclear Power

  • Renewable Energy Benefits:

    • Cleaner, greener, and cost-effective compared to non-renewable sources.

    • Usage is prioritized, but reliance on non-renewable sources continues when renewable generation is low.

  • Electricity Market:

    • Generated electricity is sold on the wholesale market to energy suppliers.

Stage 2: Transmission – Sending Electricity Around the Country

  • Transmission Network:

    • Functions similarly to motorways, transporting high-voltage electricity from generation points.

  • Role of National Grid:

    • Manages the electricity transmission network including pylons, overhead lines, and underground cables.

    • Responsible for building and maintaining infrastructure to carry electricity across England and Wales.

Stage 3: Distribution – How Electricity Reaches Homes

  • Connection to Communities:

    • Distribution networks act like local roads, linking transmission networks to neighborhoods.

  • Voltage Management:

    • High-voltage electricity is stepped down at distribution substations for safe use in homes.

  • Regional Management:

    • Local distribution network operators manage the poles, cables, and substations.

    • In the Midlands, South West England, and South Wales, the National Grid operates the distribution.

Voltage Identification

  • Live Generation Data and Voltage Levels:

    • Generation voltage: 25kV

    • Transmission (Grid system): 400kV or 275kV

    • Distribution (locally): 132kV, 66kV, 33kV, 11kV, 400/230V

    • Other voltages may be encountered.

    • Transformers are essential for stepping up and down voltage levels to manage current and power effectively.

Additional Notes

  • Direct Current (D.C.) Transmission:

    • A D.C. line between the UK and France mitigates normal A.C. losses.

    • High voltage is not suitable for end-users; transformers reduce it to safe levels.