The Raritan Blog

Active Power and Apparent Power

James Cerwinski
July 15, 2009

Apparent Power is the Total Power Flowing

When electrical power in an AC system flows to a load (a computer, motor, lighting, cooling, etc.) all of the power is not necessarily absorbed and used to perform useful work – a portion of the power may be reflected back to the power source (power company).

The total power flowing is known as the “apparent power” and is measured as the product of the voltage and current (V * I).. For example, if 208 volts and 5 amps are measured – the apparent power is 1040VA (VA means volt-amps – the measurement unit of apparent power).