Why is the mains electricity AC?


Electricity is generated at voltages of several thousand volts. For it to be transported via the electrical grid, the voltage is increased to hundreds of thousands of volts. This allows thinner conductors to be used because a current is lower when the voltage is increased. Also, lower current results in lower power losses in cables because a loss is proportional to a current squared. The advantage of AC is that voltage can be easily increased and decreased by the use of transformers. Also, induction motors that use AC can run much more silent than those that use DC (e.g., fridge, freezer, and washing machine motors).

Updated on April 9, 2018

Original Article:

Watts, Amps and Volts, Kilowatt Hours (kWh) and Electrical Appliances  - Basic Electricity Explained
By Eugene Brennan