The Reactive Power charge which is itemised on your electricity bill is directly targeted against those companies who do not demonstrate clear energy efficiency use, and who therefore have a low power factor.

Basically power factor is a measure of the efficiency of an electrical supply and how efficiently electrical power is consumed. Power factor is reduced by equipment such as electric motors, welding sets, fluorescent and high bay lighting which create inefficiencies. The higher the power factor, the more efficiently energy is being used. Reactive Power charges can be significantly reduced by the introduction of power factor correction which reduces electrical load and minimises wasted energy, improving the efficiency of a site and reducing the electricity bill. That means less money down the drain for you.

Power Factor
Power factor is the relationship between ACTIVE POWER (kW) (real power) and the total energy consumed or APPARENT POWER (kVA) in an electrical system. The ratio of active power (kW) to the apparent power (kVA) in an inductive circuit is known as
the power factor or Cos of the system. i.e.

Power factor (PF) or Cos kW = electrical efficiency kVA.

Electrical Systems
All inductive electrical systems have 3 power components…
Reactive Power (kVAR)
Required to maintain the electromagnetic field but contributes nothing to the useful output of the system. All inductive apparatus uses this principle of operation. The electromagnetic field power is called the REACTIVE POWER and is measured in volt-amperes.
Active Power (kW)
The useful work done by the motors etc on the system and measured in kW.
Apparent Power (kVA)
This is the total energy consumed or the total energy supplied by the electricity authority. It is the vector addition of ACTIVE and REACTIVE POWER, as shown in the sketch below.

i.e. kVA2 = kW2 + kVAR2
For economical power transmission, the reactive power component (kVAR) within the apparent power (kVA) must be reduced or eliminated. This in turn improves the power factor of the system and hence available capacity (i.e. electrical efficiency improves).

Why Correct the Power Factor?
All electricity authorities charge in some way for reactive power used (kVARh). This may be included in the kVA demand on the account or identied separately as a REACTIVE POWER CHARGE. Whatever the charge levied it can be totally eliminated by improving the power factor.

Power factor improvement by capacitors
Compensation by capacitors eliminates the need for the transmission of reactive power by the distribution network therefore eliminating the need for larger transformers and cables etc.

The advantages of capacitors
• Capacitors are a relatively low cost item.
• Capacitors are static equipment therefore low maintenance costs.
• Capacitors are easily installed.
• Capacitors have a long life (20-25 years)

It pays to have a high power factor to eliminate costs when negotiating electricity contracts.
The Importance of Power Factor in Distribution Systems
The signicance of power factor lies in the fact that utility companies supply customers with volt-amperes, but bill them for watts.

Power factors below 1.0 require a utility to generate more than the minimum volt-amperes necessary to supply the real power (watts). This increases generation and transmission costs. For example, if the load power factor were as low as 0.7, the apparent power would be 1.4 times the real power used by the load. Line current in the circuit would also be 1.4 times the current required at 1.0 power factor, so the losses in the circuit would be doubled (since they are proportional to the square of the current). Alternatively all components of the system such as generators, conductors, transformers, and switchgear would be increased in size (and cost) to carry the extra current.

Utilities typically charge additional costs to customers who have a power factor below some limit, which is typically 0.9 to 0.95. Engineers are often interested in the power factor of a load as one of the factors that affect the efficiency of power transmission.

Power Factor Correction
Our PFC solutions help you to increase power factor on your system. This means that you will benefit in a number of ways:
• A higher power factor reduces the kVA maximum demand and usage required to achieve your kWh usage
• It can reduce your maximum demand charge
• It reduces your reactive power usage, which can reduce your reactive power charges from the electricity company
• It improves your site efficiency
• It demonstrates your green carbon credentials
• It maximises the capacity of your system
• It reduces sporadic tripping of circuit breakers and therefore potentially losing supply
• PFC Increases the supply’s output power capability