What are network losses and where do they come from?

What are network losses from a technical perspective?

Network losses are defined as the difference between the electrical energy introduced into the network and the energy actually received by end users. From a technical perspective, this is an unavoidable phenomenon resulting from the laws of physics and the construction of power infrastructure components. Their level depends both on network parameters and on the way it is operated.

In practice, two basic categories of losses are distinguished.

• The first consists of technical losses, also referred to as physical losses, which arise as a result of current flowing through network components.
• The second group consists of non-technical losses, related, among others, to measurement irregularities or illegal energy consumption.

From the point of view of distribution system operators, technical losses are of the greatest importance because they are directly related to the operation of infrastructure. An important element of the analysis is also the distinction between active and reactive power losses. Active power losses are associated with actual energy consumption, whereas the presence of reactive power affects the increase of network loads and indirectly leads to an increase in total losses. Improper network operating parameters, including a low power factor, may worsen its efficiency.

Losses arise in various parts of the power system. They most often occur in transmission and distribution lines, where energy is dissipated in conductors, as well as in transformers, where magnetic and thermal losses occur. Additionally, auxiliary infrastructure elements, such as metering and protection devices, also have an impact, as they generate a certain level of losses.

How do energy losses occur in the network?

1. One of the basic mechanisms causing losses is the so-called Joule losses, resulting from the flow of current through conductors with a certain resistance. Their magnitude increases with increasing current intensity and is proportional to the square of its value (I²R). This means that under high network loads, losses can increase rapidly, especially in the case of lines with insufficient technical parameters.
2. Transformers are also a significant source of losses, where both no-load losses, associated with core magnetization, and load losses, dependent on the flowing current, occur. Although a single device generates relatively small losses, their scale throughout the system can be high due to the large number of units in operation.
3. The level of losses is also affected by the presence of reactive power and the value of the power factor (cos φ). A low value of this parameter means that more current circulates in the network than would result from the demand for active power. This leads to additional loading of infrastructure components and an increase in losses. For this reason, maintaining appropriate energy quality parameters is of significant importance for the efficiency of system operation.
4. An additional factor is power quality disturbances, including harmonics. They cause distortions of current and voltage waveforms, which translate into increased losses in conductors and devices. In practice, this means that even under seemingly correct network loading, additional sources of losses that are more difficult to identify may occur.

How are network losses measured and analyzed?

The basic tool for assessing the level of losses is energy balancing, carried out at various levels of network operation. From individual transformer stations, through distribution lines, to entire areas managed by the operator. Comparing the amount of energy introduced and received makes it possible to determine the scale of losses and identify the locations where they are the highest.

Measurement data obtained in near real time play an increasingly important role. SCADA and AMI systems enable ongoing monitoring of network operating parameters, such as voltage, current, or load. Thanks to this, operators can respond more quickly to irregularities and conduct a more precise analysis of the causes of losses. In practice, power flow analysis and load profile analysis are also used. This makes it possible to determine how energy moves through the network and which of its components are used most intensively. Such an approach enables not only the identification of losses, but also the forecasting of their level depending on changing operating conditions.

An important element is also the detection of anomalies that may indicate inefficient network operation or technical problems. Areas with elevated losses require detailed analysis because they may result from both infrastructure limitations and improper system configuration.

How can network losses be reduced?

Reducing losses requires a systemic approach covering both technical and organizational activities. One of the basic tools is the optimization of network configuration and power flows. Appropriate management of the load on individual lines makes it possible to reduce overloads and limit losses resulting from excessive current flow. Reactive power compensation and power factor improvement are of great importance. The use of devices such as capacitor banks or control systems makes it possible to reduce the flow of unnecessary reactive power, which directly translates into reduced losses in network components.

Another direction of action is infrastructure modernization. Replacing conductors with models of lower resistance, using transformers with better energy performance parameters, or optimizing the location of devices can improve system efficiency. Although this involves investment expenditures, it brings measurable economic benefits in the long term. Digital systems and data analytics are also becoming increasingly important. Advanced IT tools make it possible to monitor network operation and automatically indicate areas requiring intervention. The integration of measurement data with analytical models allows operational decisions to be made based on current system operating conditions.

Network losses are an inherent element of the operation of power systems; however, their level can be effectively reduced through appropriate technical and organizational measures. Precise measurement and continuous data analysis are of key importance, as they make it possible to quickly detect irregularities and optimize network operation. Effective loss management requires combining infrastructure modernization with the use of digital tools. Such an approach enables better use of existing resources and improvement of system operating parameters without the need for large-scale expansion.

Solutions such as Nomad NX enable ongoing monitoring of network parameters, identification of sources of losses, and making optimization decisions based on detailed data.