Electricity is carried countrywide via the National Grid at 275,000 or 400,000 volts. It is reduced to 132,000 volts for regional distribution at substations known as Grid Supply Points. From there it is disseminated to further substations via overhead lines or underground cables at 132,000 volts. The voltage is reduced again to 33,000 volts and then to 11,000 volts.
This distribution network then carries electricity to individual towns and villages throughout the Midlands, South West and Wales where distribution substations transform the voltage to 230 volts.