The National Grid

This lesson covers the National Grid — the system that transmits electrical energy from power stations to consumers across the country — as required by AQA GCSE Combined Science Trilogy (8464, section 6.2.2).

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What Is the National Grid?

The National Grid is a network of cables, pylons and transformers that connects power stations (and other electricity generators) to homes, businesses and factories across the UK.

Its purpose is to transfer electrical energy efficiently from where it is generated to where it is needed.

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How the National Grid Works

flowchart LR
    A["Power Station<br/>~25 000 V"] --> B["Step-Up Transformer<br/>Increases voltage to ~400 000 V"]
    B --> C["High-Voltage Transmission Lines<br/>(pylons and cables)<br/>~275 000 – 400 000 V"]
    C --> D["Step-Down Transformer<br/>Decreases voltage to ~230 V"]
    D --> E["Homes, Schools,<br/>Businesses<br/>~230 V"]

1. Electricity is generated at a power station at about 25 000 V.
2. A step-up transformer increases the voltage to about 400 000 V for transmission.
3. Electricity is transmitted at high voltage and low current through overhead cables on pylons (or underground cables).
4. A step-down transformer reduces the voltage to 230 V for safe use in homes and businesses.

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