Reactive power is the term used to describe the power that oscillates back and forth within a circuit or acts upon itself, resulting in movement in both directions. It is measured in units of kilovolt ampere reactive (kVAR) or MVAR.
Reactive power is a form of power that does not perform actual work and is primarily associated with reactive elements like inductors and capacitors. For instance, inductive loads such as motors cause the current to lag behind the voltage. The power that appears across the inductance alternates between the inductance itself and the power sources, without any network being done. This is why it is referred to as imaginary or reactive power, as it does not dissipate or expend any power. Its measurement is expressed in volt-ampere-reactive (VAR) units.
Managing Reactive Power Charges through Power Factor Correction
Installing power factor correction capacitors is a recommended approach to avoid incurring charges for reactive power. In general, residential customers are billed based on the active power they consume in kilowatt-hours (kWh). This is because most residential and single-phase power systems have similar power factor values, which are maintained by power factor correction capacitors integrated into household appliances during manufacturing.
However, industrial customers that utilize three-phase power supplies often exhibit varying power factors. Consequently, electrical utility companies may need to consider the power factor of these industrial customers and impose penalties if their power factor falls below a specified threshold. The reason behind this is that supplying power to industrial customers requires larger conductors, transformers, switchgear, and other equipment capable of handling higher currents, which incurs higher costs for utility companies.
Also Read: What is Power Conversion Efficiency?