Ancillary control services (ACS)

services provided to the transmission system operator, which are indispensable for the proper functioning of the national power system and ensure the keeping of required reliability and quality standards.

Achievable capacity

The maximum sustained capacity of a generating unit or generator, maintained continuously by a thermal generator for at least 15 hours or by a hydroelectric generator for at least five hours, at standardized operating conditions, as confirmed by tests.

Balancing market

a technical platform for balancing electricity supply and demand on the market. The differences between the planned (announced supply schedules) and the actually delivered/offtaken volumes of electricity are settled here. The purpose of the balancing market is to balance transactions concluded between individual market participants and actual electricity demand. The participants of the balancing market can be the generators, customers for electricity understood as entities connected to a network located in the balancing market area (including offtakers and network customers), trading companies, electricity exchanges and the TSO as the balancing company.

Base, baseload

a standard product on the electricity market: a constant hourly power supply per day in a given period, for example week, month, quarter or year.


Solid or liquid substances of plant or animal origin, subject to biodegradation, obtained from agricultural or forestry products, waste and remains or industries processing their products as well as certain other biodegradable waste in particular agricultural raw materials.

Black energy

popular name for energy generated as a result of combustion of black coal or lignite.


Carbon Capture and Storage Technology used to capture CO2 from the emissions of fossil fuel power plants followed by its underground storage.


Clean Development Mechanisms, one of the flexible mechanisms introduced under Article 12 of the Kyoto Protocol.


Certified Emission Reduction.


the generation of electricity or heat based on a process of combined, simultaneous combustion in one device of biomass or biogas together with other fuels; part of the energy thus generated can be deemed to be energy generated with the use of renewable sources.


the simultaneous generation of heat and electricity or mechanical energy in the course of one and the same technological process.

Constrained generation

the generation of electricity to ensure the quality and reliability of the national power system; this applies to generating units in which generation must continue due to the technical limitations of the operation of the power system and the necessity of ensuring its adequate reliability.


transport of energy through distribution grid of high (110 kV), medium (15kV) and low (400V) voltage in order to supply the customers.

Distribution System Operator (DSO)

a power company engaging in the distribution of gaseous fuels or electricity, responsible for traffic in the gas or electricity distribution systems, current and long-term security of operation of the system, the operation, maintenance, repairs and indispensable expansion of the distribution network, including connections to other gas or power systems.


Energy Regulatory Office (pol. URE).


Emission Reduction Units.


European Union Allowances: transferable CO2 emission allowances; one EUA allows an operator to release one tonne of CO2.


European Union Greenhouse Gas Emission Trading Scheme) EU emission trading scheme. Its operating rules are set out in the ETS Directive, amended by the Directive 2009/29/EC of the European Parliament and of the Council of April 23, 2009 (OJ EU L. of 2009, No. 140, p. 63—87).

Generating unit

a technically and commercially defined set of equipment belonging to a power company and used to generate electricity or heat and to transmit power.


Gigajoule, a unit of work/heat in the SI system, 1 GJ = 1000/3.6 kWh = approximately 278 kWh.


main power supply point, a type of transformer station used for the processing or distribution of electricity or solely for the distribution of electricity.

Green certificate

popular name for energy generated from renewable energy sources.


gigawatt, a unit of capacity in the SI system, 1 GW = 109 W.


one gigawatt of electric capacity.


one gigawatt of heat capacity.

High Voltage Network (HV)

a network with a nominal voltage of 110 kV.

Highly efficient co-generation

the generation of electric or mechanical power and useful heat through co-generation, in such a way as to ensure savings of primary energy used in: (i) a co-generation unit in the amount not lower than 10 per cent. as compared to generation of electric power and heat in separated systems with reference efficiency for separated generation; or (ii) co-generation unit with an installed capacity under 1 MW as compared to generation of electric power and heat in separated systems with reference efficiency for separated generation.


Integrated Gasification Combined Cycle.

Installed capacity

the formal value of active power recorded in the design documentation of a generating system as being the maximum achievable capacity of that system, confirmed by the acceptance protocols of that system (a historical value, it does not change over time.


the Transmission Network Operation and Maintenance Manual required to be prepared by a transmission system operator pursuant to the Energy Law; instructions prepared for power networks that specify in detail the terms and conditions of using these networks by system users as well as terms and conditions for traffic handling, operation and planning the development of these networks; sections on transmission system balancing and system limitation management, including information on comments received from system users and their consideration, are submitted to the ERO President for approval by way of a decision.


Joint Implementation: one of the flexibility mechanisms introduced under Article 6 of the Kyoto Protocol.

Kyoto Protocol

the Kyoto Protocol to the United Nations Framework Convention on Climate Change of December 11, 1997 (Dz.U. of 2005, No. 203, Item 1684), in force since February 16, 2005.


the National Power System, a set of equipment for the distribution, transmission and generation of electricity, forming a system to allow the supply of electricity in the territory of Poland.


the National Transmission System, a set of equipment for the transmission of electricity in the territory of Poland.


kilo volt, an SI unit of electric potential difference, current andelectromotive force; 1kV= 103 V.


kilowatt-hour, a unit of electric energy in the SI system defined as the volume of electricity used by the 1 kW equipment over one hour. 1 kWh = 3,600,000 J = 3.6 MJ.

Medium-voltage network (MV)

an energy network with a nominal voltage higher than 1 kV but lower than 110 kV.


Minimum Energy Volumes.


a unit of capacity in the SI system, 1 MW = 106 W.


one megawatt of electric power.


one megawatt of heat power.


National emissions Allocation Plan, prepared separately for the national emission trading system and for the EU emission trading system by the National Administrator of the Emission Trading System.


National CO2 emissions Allocation Plan for the years 2008-2012 prepared for the EU emission trading system adopted by the Ordinance of the Council of Ministers of July 1, 2008 (Dz. U. of 2008, No. 202, item 1248).


normal cubic meter; a unit of volume from outside the SI system signifying the quantity of dry gas in 1 m3 of space at a pressure of 101.325 Pa and a temperature of 0°C.


nitrogen oxides.

Peak, peakload

a standard product on the electricity market; a constant power supply from Monday to Friday, each hour between 7:00 a.m. and 10:00 p.m. (15-hour standard for the Polish market) or between 8:00 a.m. and 8:00 p.m. (12-hour standard for the German market) in a given period, for example week, month,quarter or year.

Peak power pumped storage plants

a special kind of hydroelectric power plants. In addition to river flow and the difference in the water table levels they need two bodies of water connected with a channel or a pipeline. The power station is situated next to the lower lake or at the dam of the upper lake. The pumped storage facilities provide ancillary control services for the national power system. Their functions are to secure stability, provide passive energy, store excessive power in the system and supply power to the system in peak time. The pumped storage plants that have a natural inflow of water to the upper lake also generate electricity from renewable sources. The main offtaker of electricity produced by the peak power pumped storage power stations and their services is the TSO.


an Internet electricity trading platform operated by ELBIS Sp. z o.o., used for various sale and purchase transactions of conventional energy, property rights, renewable energy and CO2 emission allowances.

Property rights

Negotiable exchange-traded rights under green and co-generation certificates.


Regulatory Asset Base.

Red certificate

a certificate confirming generation of electricity in co-generation with heat.

Red energy

popular name for electricity co-generated with heat.


the President of ERO, fulfiling the tasks assigned to him in the energy law. The regulator is responsible for, among others, giving out licenses for energy companies, approval of energy tariffs, appointing Transmission System Operators and Distribution System Operators.

Renewable Energy Source (RES)

a source of generation using wind power, solar radiation, geothermal energy, waves, sea currents and tides, flow of rivers and energy obtained from biomass, landfill biogas as well as biogas generated in sewage collection or treatment processes or the disintegration of stored plant or animal remains.


the list of prices and rates and terms of application of the same, devised by an energy enterprise and introduced as binding on the customers specified therein in the manner defined by an act of parliament.

Tariff group

a group of customers offtaking electricity or heat or using services related to electricity or heat supply to whom a single set of prices or charges and terms are applied.


Tradition Financial Services, an electricity trading platform used for concluding various transactions, purchase and sale of conventional energy, property rights, renewable energy and CO2 emission allowances.


Towarowa Giełda Energii S.A. (Polish Power Exchange), a commodity exchange on which trading can take place in electricity, liquid or gas fuels, extraction gas, emission allowances and property rights whose price depends directly or indirectly on electric energy, liquid or gas fuels and emission allowances, admitted to commodity exchange trading.

TPA, TPA rule

Third Party Access, the owner or operator of the network infrastructure to third parties in order to supply goods/services to third party customers.


transport of electricity through high voltage (220 and 400 kV)transmission network from generators to distributors.

Transmission System Operator (TSO)

a power company engaging in the transmission of gaseous fuels or electric energy, responsible for traffic in a gas or power transmission system, current and long-term security of operation of that system, the operation, maintenance, repair and indispensable expansion of the transmission system, including connections with other gas or power systems. In Poland, for the period from January 1, 2008 till July 1, 2014 Polskie Sieci Elektroenergetyczne Operator S.A. was chosen as a TSO in the field of energy transmission.


terawatt hour, a multiple unit for measuring of electricity unit in the system SI. 1 TWh is 109 kWh.


the Union for the Co-ordination of Transmission of Electricity, an organization co-ordinating the synchronous operation of interconnected European electricity transmission systems (the organization does not cover Scandinavian countries).

Ultra high-voltage network (UHV)

an energy network with a voltage equal to 220 kV or higher.

V (volt)

electrical potential unit, electric voltage and electromotive force in the International System of Units (SI), 1 V= 1J/1C = (1 kg x m2) / (A x s3).

W (watt)

a unit of power in the International Systems of Units (SI), 1 W = 1J/1s = 1 kg x m2 x s-3.

Yellow certificate

a certificate confirming generation of energy in gas-fired power plants and CCGT power plants.

Yellow energy

popular name for energy generated in gas-fired power plants and CCGT power plants.