Reactive Power Reduction by use of Power Factor Correction.

A customer who owns an Injection Moulding company in Dorset that were receiving reactive charges on their electricity bills due to a poor site Power Factor.

Site were able to provide us with their half hourly consumption data over the period of 1 month and we calculated that to improve the Power Factor from 0.83 inductive to a satisfactory level, 100kVAr of PFC would be required.



Based on your Network Operators “Use of System” charges for supplies metered at low voltage (H87 LLF), we estimate that the improved conditions would provide the following potential savings:


Reactive Power Charge Reduction:                             £318.00 + VAT*

Excess Supply Capacity Reduction:                            £788.92 + VAT

Total Potential Annual Savings:                                   £1,106.93 + VAT

*Excess reactive power savings will increase during summer months due to increased solar generation



Potential Annual Savings                                  £1,106.93 + VAT

Payback period                                                 39.2 months

(Ongoing savings assume a 10% year on year increase in electricity costs)


We were also informed that site has some old none functioning PFC equipment on site including what we identified as a capacitor bank containing polychlorinated biphenyls (PCBs) which are dangerous to human health and to the environment. And as such requires specialist waste disposal.

Our engineer attended site to carry out the removal of the existing equipment and the installation of the new FS100 PFC unit with most the works being carried out during normal working hours with final connections done out of hours during a shutdown period.



The suspected PCB capacitor bank was checked for any leaks and bagged up safely ready for specialist disposal.


On completion of the works sites power factor was now at 0.99i and greatly reduced the sites reactive power.

The graph below showing the reactive power monitored by site before and then after the installation.