When you look at the bottom of your energy bill, do you see a line called "reactive energy charge"? If you do, and this charge exceeds 10% of your total bill, a compensation panel investment will likely pay for itself within 12–18 months. In this article, we explain step by step what reactive power is, how it is measured, and how you can reduce your bill by installing a compensation system.
Electrical energy consists of two components: active power (kW), which actually performs useful work, and reactive power (kVAr), which travels back and forth in the system to create electromagnetic fields without directly performing useful work. Motors, transformers, ballasts, and uninterruptible power supplies (UPS) are the main consumers of reactive power.
The combination of these two components forms apparent power (kVA). The power factor (cosφ) is the ratio of active power to apparent power. In Turkey, distribution companies apply a reactive energy charge when the power factor drops below 0.90. For large industrial subscribers, this charge can amount to tens of thousands of Turkish Lira per year.
This calculation is based on the reactive energy charge alone. In addition, when the power factor is corrected, transformer and cable losses decrease, more active load can be supplied from the existing line capacity, and equipment lifespan is extended.
An automatic compensation panel contains a power factor relay (regulator) that continuously monitors the grid. When the reactive power demand increases, the regulator switches capacitor banks in sequentially; when demand decreases, it switches them out. This keeps the cosφ at the target value at all times.
Important note for facilities with harmonic problems: If there are harmonic-generating loads such as frequency converters (inverters), UPS units, or arc furnaces, standard capacitor banks are not sufficient. In such cases, detuned capacitor banks with filter reactors or active filter systems are required. A compensation system installed without a harmonic analysis will lead to early capacitor failure.
To size a compensation system correctly, at least one week of energy analyser measurements must be taken. The analyser records hourly active power, reactive power, power factor, and harmonic distortion data. By examining this data:
As Adas Mekatronik, we provide a complete compensation solution from energy analyser measurement and panel design through to manufacturing and commissioning. We guarantee the power factor after delivery.
IEC 61439-compliant, project-based engineering solutions for industrial automation panel design and manufacturing.
