Reactive Power Compensation: Your Key to cost efficiency, regulatory compliance, and relief for your electrical grid Infrastructure

How compensation systems boost your operation's energy efficiency and cut costs simultaneously

Dear Readers,

do you know how much cables, fuses, and transformers in your operation are stressed by reactive power?

The power grid is changing. With the increasing use of power electronic consumers and the volatile feed-in of renewable energies, the requirements for industrial supply networks are fundamentally shifting. For many companies, ensuring a stable and efficient power supply is becoming an increasingly crucial production and competitive factor.

An often underestimated influencing factor here is reactive power. Absent, incorrectly dimensioned, or outdated compensation systems can not only lead to unnecessary costs but also jeopardize operational safety and shorten the service life of electrical equipment. Precisely designed compensation systems, on the other hand, regulate reactive power accurately, relieve your cables, fuses, and transformers, and ensure compliance with the cos φ required by the grid operator for an economically and technically optimized plant operation.

Compliance with the reactive power factor (cos φ) required by the grid operator must not be neglected. The grid operator’s requirements are not a suggestion, but a mandatory condition! Otherwise, additional charges or grid-side measures may be imposed.

Understanding reactive power: properly classifying active, apparent, and reactive power in industrial plants

Reactive power is the portion of electrical power that oscillates back and forth between the energy source and consumers in AC networks without performing any actual useful work. It primarily arises from inductive or capacitive loads such as motors, transformers, or capacitances (e.g., cables or rail systems) and is necessary to establish electromagnetic fields.

In contrast, active power (P) describes the portion of electrical power that is actually converted into mechanical work, heat, or light.

Apparent power (S), meanwhile, encompasses the total power that an electrical network must provide. It consists of active and reactive power and determines, among other things, the required conductor cross-section as well as the loading of transformers and switchgear.

The relationship is given by:

Formel Blindleistung

This relationship becomes more understandable when represented in the so-called power triangle.

A high reactive power component stresses lines and equipment without generating additional benefit – which is why it is reduced through appropriate compensation measures. A good power factor (cos φ) means that a high proportion of the apparent power is actually usable as active power.

In previous technical reports, we have already addressed reactive power – so our eager readers already know the basics. Those who want to stay up to date benefit from subscribing to our newsletter and won’t miss any tips on grid optimization and energy efficiency.

Leistungsdreieck mit und ohne Kompensation von Blindleistung | Power Triangle With and without reactive power compensation
Figure 1: The power triangle illustrates the relationships between reactive power Q, apparent power S, and active power P—with and without compensation

Rising Requirements from Standards and Grid Operators

With the continuous development of the Technical Connection Conditions (TAB) and VDE application rules—particularly VDE-AR-N 4105 and 4110—the requirements for companies are steadily increasing. These regulations define binding framework conditions for safe grid operation and voltage stabilization.

Inadequate reactive power compensation can lead to:

  • Transformers and lines being more heavily loaded
  • Additional reactive power costs arising from grid operator billing
  • Reduced energy efficiency of the overall system
  • Non-compliance with grid operator requirements, potentially resulting in power supply disconnection in the worst case

Grid operators typically specify power factors in the range of cos φ 0.9 inductive to 1 capacitive for low voltage. If this range is permanently undershot, additional grid usage charges may apply. Stricter requirements apply to medium voltage as outlined here.

Properly dimensioning compensation systems: Key factors for stable industrial networks

Planning a compensation system today requires far more than just determining the required reactive power. A comprehensive analysis of the actual grid conditions is crucial.

Key design parameters include:
Load Structure Analysis 

Beyond installed capacity, actual energy quantities of active and reactive work, simultaneous load/consumer occurrence, and dynamic load changes must be considered. Only this enables precise staged control.

Voltage Quality Assessment 

Analysis of harmonics, flicker, and potential resonance phenomena is crucial for safe design. In particular, the selection and tuning of reactors requires sound expertise to avoid overloads or unwanted resonances.

Consideration of Environmental Conditions

Thermal loads, installation locations, and expansion options significantly influence technical requirements and thus the service life and operational reliability of the system.

Own Generation Facilities, Such as Photovoltaic Systems

A properly dimensioned compensation system substantially contributes to reducing energy losses and relieving equipment.

Oszilloskopbild Netzmessung | Oscilloscope Image of Grid Measurement
Figure 2: Ideal compensation requires a grid measurement. It captures not only load profiles but also disturbance factors like harmonics, flicker, and potential resonance phenomena.

Why Standard Compensation Systems Often Fall Short

Companies and their power networks vary greatly in structure, load behavior, and grid quality. Standardized solutions can often only account for these differences to a limited extent.

Depending on the application, different compensation concepts are used, such as:

The selection of the appropriate technology is crucial for operational safety, cost-effectiveness, and future-proofing of the system.

KBR EnergyManagement: Experience Meets Modern Measurement Technology

KBR EnergyManagement has supported industrial companies for decades in planning and implementing efficient energy network solutions. The foundation for this is the combination of professional grid analysis, modern measurement technology, and in-house manufacturing.

KBR solutions are distinguished particularly by the following features:

  • Individual design based on real measurement data
  • Modular construction for future expansions
  • In-house manufacturing in Germany for reliable quality


This provides companies not only with a technically suitable compensation solution but also long-term investment security.

Varianten Anlagen zur Kompensation von Blindleistung | Variants of Systems for Reactive Power Compensation
Figure 3: Modular and perfectly tailored to your operation: Compensation systems from KBR.

Securely complying with grid requirements – Act Now

Optimizing reactive power compensation offers significant potential in many industrial companies to reduce energy costs and relieve grid infrastructure. A prerequisite is a thorough analysis of the existing network structure.

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Configure your system easily yourself!

Whether new installation or retrofit: With our configurator, you quickly receive a non-binding, tailored concept for your reactive power compensation.

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Still have open questions or want to deepen your knowledge?

Gain practical expertise in our webinar on reactive power compensation.

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Need an individual analysis or consultation?

Our experts analyze your measurement data and develop concrete action recommendations for economical, future-proof optimization. We’re also happy to assist with any further questions.

Jonas Klaus | Technischer Redakteur

Yours, Jonas Klaus

Technical Editor
KBR GmbH