The companion question to this is: why is the power in homes 120V AC? Electricity is transmitted from power plants to homes and businesses in high voltage form (AC: alternating current) because AC power can cover longer distances, sustain the loss of power through wires, and be distributed to many locations. Besides the fact that large appliances such as washers and dryers need a lot of power, that's the main reason that power coming out of an electrical outlet is 110-220V AC. Most small appliances in the home are low voltage, usually somewhere between 3V and 24V DC (direct current). Low voltage appliances are generally safer than high voltage appliances and fixtures, with less risk of shock and fire, and require much less power.