Key terms and issues explained

Mae’r dudalen yma ar gael yn Gymraeg.

On this page you will find a range of key terms explained for business energy. Please click on a letter below to be taken to a list of terms and on "show" to read the explanation.

Unilateral Variation

An amendment to the terms and/or conditions (including price) of a consumer’s energy supply contract, which is provided for in the contract and is at the sole discretion of the supplier.


One kilowatt of power being used for one hour. It is the same as a 40-watt light bulb being left on for 25 hours. Also known as a ‘unit’ of energy.

Unit Rate

The monetary amount that is chargeable in respect of each unit of gas/electricity consumed.