Power Factor Correction

ESTA can supply your entire requirement and in both standard and detuned automatic power factor correction systems for all kinds of network conditions. In today’s environment where variable speed drives are common and networks have become polluted with harmonics, it is important that a proper assessment of the network is undertaken before designing a power factor correction system.


We provide the state of the art power quality solutions to every kind of industry. If you want more info on our Power Quality Solutions, you can visit estapqs.co.uk with the button above or the image here.

Wattless Charges Explained

In large commercial or industrial premises, there are items of electrical equipment that require wattless energy to operate. Wattless energy is measured separately from your general units, and if you exceed a certain limit, it will give rise to a separate charge.

How wattless charges work

Electric power consists of two components: active power and reactive power. Active power is recorded on your normal electricity meter, and appears on your bill as general day and night units.
Reactive power is also recorded by your normal meter, but will only affect you if you are an industrial or commercial business user. This is because certain equipment common to industrial or other large businesses – such as motors or fluorescent lights need reactive power in order to operate.

Your wattless unit allowance

If the number of wattless units you use in a single billing period exceeds a limit of one-third of all your general units (both day and night), then a charge will apply. The charge per unit depends on your Business tariff.

We use the term power factor to explain this one-third ratio between active and reactive power or general and wattless units. An overall power factor of 0.95 must be maintained in order to avoid wattless charges. If your consumption of wattless units increases above one-third of your general units per bill, the power factor will drop below 0.95, and the excess wattless units will incur a charge.

How to reduce wattless charges

You should contact ESTA your electrical contractor to fit power factor correction equipment. This will reduce the amount of reactive power you consume and help to avoid wattless charges on your bills.

Cost Considerations

Weigh the cost of fitting special Power Factor Correction Equipment, and how it will reduce wattless charges on your bill. The rate at which the new device will pay for itself naturally varies according to the level of wattless charges you have incurred. 
ESTA will be happy to assist you with a design specific to your requirements.