The National Grid

What’s the national grid?

A nationwide network of cables and transformers that link power stations to homes, offices and other consumers of mains electricity.

What are transformers?

Devices that can change the potential difference of an alternating current.

What do power stations generate?

Electricity at an alternating potential difference of about 25,000 V.

What do the cables in the National Grid transfer?

Electrical power at a potential difference of up to 400,000 V.

What do homes and offices use?

Electrical power supplied at a potential difference of 230 V.

What are step-up transformers used?

To increase the potential difference from the power station to the transmission cables.

What are step-down transformers used?

To decrease the potential difference from the transmission cables to the mains supply in homes and offices so that it’s safe to use.