On this page you will find a range of key terms explained. Please click on a letter below to be taken to a list of terms and on "show" to read the explanation.
Terms for letter 'Z'
The large energy suppliers (often also called the 'Big Six') are the companies that hold supply licences and supply most of the energy to domestic households in the GB market. They are:
Centrica plc (parent company of British Gas), E.ON UK, Scottish and Southern Energy (SSE), RWE npower, EDF Energy and ScottishPower.
A consumer who annually uses 2.100 kWh of electricity and/or 11.000 kWh of gas.
A discount that is paid at a pre-specified point in time if the consumer does not switch energy suppliers.