Definition: A kilowatt-hour (kWh) is the standard unit of energy on UK bills: one kilowatt of power used for one hour. Electricity currently costs about 24.67p per kWh under the Q2 2026 price cap.

Everyday examples

A 3kW kettle running for 20 minutes uses 1 kWh. A typical UK home uses 2,700 kWh of electricity and 11,500 kWh of gas per year.

Why it matters for upgrades

Savings estimates are built on kWh: a solar system generating 3,400 kWh a year offsets electricity you’d otherwise buy at full price — that’s the saving.

Estimate your numbers: try the free savings calculator or browse all upgrade guides.