About PSE

We are the only electricity transmission system operator within the territory of Poland. We play a key role in efficient functioning of the Polish economy. We care about the reliability of electricity supply to all regions of the country.

We also ensure the secure and cost-effective operation of the Polish power system as part of the common European system.

About PSE

PSE’s role in the power sector

We live in an era of electricity. Electric energy powers not only innumerable pieces of equipment but also all areas of our lives. Power lines and electrical substations have become permanent features of our landscape and today it would be hard for us to imagine daily living without electricity.

Yet few people are aware of how complex processes must take place “on the other side” of the power socket to ensure stable, undisturbed electricity supply.

Continuity of electricity supply is a result of an efficiently operating power system which comprises energy generating, converting, transmitting and distributing systems. The operation of the system is managed and electricity supply is taken care of by Polskie Sieci Elektroenergetyczne.

GRI 103-1

How does the power system work?

The Polish Power System PPS consists of three subsystems responsible for specific function

Electricity generation ─ electric energy production by generating sources in the power system – power plants, CHP plants and distributed sources.
Electricity transmission ─ performed over the transmission network in order to deliver electric energy to distribution networks or transmission-connected consumers. Electricity transmission is performed by the transmission system operator whose functions are performed by PSE.
Electricity distribution ─ delivery of electric energy over distribution networks to institutional and individual distribution-connected consumers. Electricity distribution is performed by distribution system operators.

Generation

Transmission

Distribution

Energy sources in the power system

Electricity supplied to our homes is generated mainly in power plants and combined heat and power (CHP) plants. In Poland, the basic energy generating sources are thermal power plants in which energy is generated as a result of coal combustion – usually by burning hard coal or lignite. The largest cluster of those plants is situated in the southern part of the country. In larger cities, CHP plants operate which are mostly fired with coal, but also natural gas. Generation of energy from renewable sources ( RES )– wind, water, biomass and sun – is also being developed.

The key thermal plants in Poland include: Bełchatów, Kozienice, Opole, Turów, Połaniec, Rybnik, Pątnów, Dolna Odra, Jaworzno, Łaziska and Łagisza.

The largest hydroelectric power plants are the Żarnowiec, Porąbka-Żar, Solina, Żydowo and Dychów pumped storage plants, and the Włocławek run-of-river plant.

Electricity transmission and distribution

Energy transmission from power plants to consumers is possible over an extensive network of power lines and electrical substations. Depending on the distance over which electricity is transmitted, different voltage levels are used to optimise costs.

The path of electricity from generator
to consumer

The path of electricity from generator to consumer

Energy generating sources

Energy supplied to our homes is generated mainly in power plants and combined heat and power (CHP) plants. In Poland, the basic energy generating sources are thermal power plants in which energy is generated by burning hard coal or lignite. Generation of energy from renewable sources (RES) – wind, water, biomass and sun – is also being developed.

The path of electricity from generator to consumer

Electricity transmission by PSE

Electricity transmission from the generator to various consumer groups requires the operation of a complex structure composed of many electric power facilities and lines, knows as the power system. The system consists of the transmission network and distribution networks. The extra-high voltage (EHV) transmission network – 400 and 220 kV in Poland – covers the territory of the whole country. The owner of the network is our company, PSE. The transmission network provides the capability to transmit electricity over long distances, including the ability to quickly change the directions and volumes of transmitted electricity. The transmission network supplies electricity to distribution systems and to large industrial consumers.

The path of electricity from generator to consumer

Electricity distribution

Distribution networks are of a regional nature. They operate high (110 kV), medium (6-30 kV) and low (230 and 400 V) voltage lines for electricity supply to consumers. In order to ensure that electricity is supplied in a sufficient quantity and meets specific parameters, the voltage level is first changed at electrical substations with the use of transformers. The administrators of distribution networks are distribution system operators. The medium voltage distribution network supplies electricity to business and industrial consumers, and first of all to final consumers using low voltage lines.

The national transmission network is fed with 50 Hz AC voltage. By comparison, in the United States 60 Hz voltage is used.
The following voltage standards have been adopted in Poland for electricity transmission:

220, 400, 750 kV (extra-high voltages) for long-distance transmission,

110 kV (high voltage) for transmission over distances not exceeding several dozens of kilometres,

6, 10, 15, 20 lub 30 kV (medium voltage) in local distribution networks,

400/230 V (low voltage) used to supply power to final consumers.
Extra-high voltages most commonly used in Europe: 220-275, 300-330 and 500 kV