Power Factor Correction

About Power Factor Correction

Power Factor Correction can help a facility significantly reduce electricity usage costs, avoid penalties that utilities impose for low power factor, earn LEED points towards LEED Certification for commercial energy conservation, reduce the load on a power grid, and free up additional capacity for more equipment. It is well-suited to any business, organization or sector that uses significant electricity:  printing, plastics (extrusion and injection), textiles, automobile manufacturing and maintenance, mills (sawills, pulp & paper mills), cement, asphalt, food processing, office towers, shopping centers, big box retailers, grocers, arenas, filling stations, hospitals, or any other large facilities that require lots of good quality power.

Power Factor Explained

Power Factor is a measure of how efficiently power is consumed.

Most electrical equipment,  such as motors or transformers, require two kinds of power: Real power (measure in kW), which is the actual “active power” that is required to do the work, and reactive power (measured in kvar), which is required in order to provide a magnetizing effect that is required by most electronics in order to perform their functions. The composition of these 2 kinds of power gives us the “apparent
power (kVA).”

The power factor (%) is the relation between the real power (kW) and the apparent power (kVA) – it is expressed as (real power) / (apparent power). The closer the power factor is to one, the closer the real power is to the apparent power – and the more optimized and efficiently the power grid is running. Low power factors occur when the apparent power is much higher than the real power, and are inefficient, wasteful and can be costly.


AC power flow has the three components: real power(Active power)(P), measured in watts (W); apparent power (S), measured in volt-amperes (VA); and reactive power (Q), measured in reactive volt-amperes (var).

The power factor, is defined as the real power (P) divided by the apparent power (S):

Power Factor Equation

Why Use Power Factor Correction?

The lower that power factor becomes, the more the power required by the distribution system exceeds the power required to do the real work. When power factor correction is employed, the power factor increases. This can lead to many direct and indirect benefits, including:

Power Factor Correction benefits electric motors

Power factor correction can provide benefits to any facility that makes use of electric motors through reduced power consumption and wear on both motors and power grids.

  • Reduced Power Consumption: Power factor correction produces an immediate improvement in energy efficiency – and therefore, an immediate reduction in electricity usage. Additionally as a recognized green method of commercial energy conservation, power factor correction can earn LEED points for organizations.
  • Reduced Electricity Costs: Power factor correction’s immediate reduction in electricity usage is also an immediate reduction in electricity costs.
  • Better Voltage Regulation, Power Line Stabilization, and Power Quality: Power factor correction produces more stable, cleaner power that allows for the optimal use of equipment.
  • Reduced Load Losses On the Distribution System: Reduced load on the system means that less losses will be incurred.
  • Increased Systems Capacity: The higher the power factor, the more efficiently the power grid is running. This means more room for more equipment, without more infrastructure, so that potentially costly upgrades can be delayed.
  • Avoid power factor surcharges: Many public and private power suppliers impose a surcharge on low power factor. BC Hydro, for example, allows a power factor as low as 90% without penalty and the applies increasing surcharges as power factor decreases, all the way up to 80% surcharge for a power factor of 50% or less. They also directly encourage power factor correction as a means of energy conservation.


Thermonic Electric – Products.” THERMONIC ELECTRIC. Thermonic Electric Co., n.d. Web. 4 Aug 2010.

Power Factor.” Wikipedia, the free encyclopedia. Wikimedia Foundation, Inc., 28 Jul 2010. Web. 4 Aug 2010.

BC Hydro – Power Factor Correction.” BC Hydro – For Generations. BC Hydro, 10 May 2010. Web. 4 Aug 2010.

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