Generating & distributing electricity (Edexcel GCSE Physics Combined Science): Revision Notes

Electrical power is transferred from power stations to consumers using the National Grid. The National Grid is a system of cables and transformers linking power stations to consumers across the UK.

Transformers: These change the potential difference

• Step-up Transformers
• Increase the potential difference from the power station to the National Grid.
• As the power remains constant (Power = Voltage × Current), increasing the potential difference reduces the current, resulting in less energy loss due to resistance in the wires.
• Step-down Transformers
• Decrease the potential difference from the National Grid to the level required by consumers.
• This is essential for consumer safety.

Energy is always lost in the power cables due to the resistance of the wires.