Power consumption

In electrical engineering, power consumption refers to the electrical energy per unit time,^[1] supplied to operate something, such as a home appliance. Power consumption is usually measured in units of watts (W) or kilowatts (kW).^[2]

Power consumption from different mobile devices

The energy used by equipment is always more than the energy really needed. This is because no equipment is 100% efficient. Power is wasted as heat, vibrations and/or electromagnetic radiation. For example, a light bulb does not only convert electric power into light; it also makes some heat.