mains electricity

A view of a switching centre, part of an electricity grid or network. This allows for power to be distributed from one area to another, where the need may be greater.

Domestic electricity supply system. In the UK, electricity is supplied to houses, offices, and most factories as an alternating current at a frequency of 50 hertz and a root-mean-square voltage of 230 volts. An advantage of having an alternating supply is that it may easily be changed, using a transformer, to a lower and safer voltage, such as 9 volts, for operating toys and for recharging batteries.