Glossary

General electroenergetic terms

These terms are based on current legislation.

Access
Possibility to access the transmission system in order to transmit electricity based on contracted transmission capacity.

Act on Energy
Act Nr. 251/2012 of Coll.

Act on Regulation
Act Nr. 250/2012 of Coll.

Allocated production
Allocated production in MW for the next year for each electricity customer is determined as arithmetical average of its monthly maxima of quaterhourly production for four consecutive months (from November last year to February of current year). The production values are defined in MW rounded to 3 decimal places.

Area price
Price valid in specified area.

ATC (Available Transfer Capacity)
Daily transmission capacity reserved for market coupling.

Balancing group
A group of electricity market participants and their off-take points on behalf of which the responsibility for imbalances has been assumed by the same entity Subject of Settlement; it is indicated by an identification number of the balancing group.

Clearing Agent
The legal entity providing clearing of imbalances (see Energy Act), i.e. clearing of differences between contractually agreed values of electricity supply or consumption and actual values of electricity supply or consumption in the specified time. OKTE, a.s. is Clearing Agent in SR.

Connection
The physical connection of electricity facility or consuming electric facility to the system.

Connection Lines
Lines that connect the transmission system with the transmission system of member states or the transmission system of third countries.

Cross-border profile
Connection lines connecting two adjacent transmission systems.

Daily diagram
The sequence of values of the agreed quantity of electricity consumption or electricity supply in MW for each trading hour of a trading day.

Day ahead Market
Known also as Day-Ahead Market, is a way of transparent trading in time close to the time of delivery (one day before the delivery normally). The market is also called Spot market and the outcome is beside others spot price definition.

Distribution system
The system of interconnected electricity lines of very high voltage up to 110 kV including and high voltage or low voltage and electricity facilities necessary for the distribution of electricity in part of the defined territory; the distribution system also includes the metering, protection, control, security, information and telecommunication equipment necessary for the operation of the distribution system; the distribution system includes the electricity line or electricity facility used for the transmission of electricity from part of the territory of the European Union to the defined territory or part of the defined territory, or from the part of the territory of third countries to the defined territory or part of the defined territory, if such electricity lines or electricity facilities do not connect the transmission system with the transmission system of a Member State of the European Union or the transmission system of third countries.

Distribution system operator - DSO
A legal person authorized to distribute electricity in part of the defined territory.

Electricity consumer
Usually the final consumer of electricity buying electricity for home consumption (production of goods and services or personal consumption) - in such case electricity consumer equals final consumer.

Electricity customer
A wholesale customer of electricity and final customer of electricity.

Electricity distribution
Transmission of electricity by the distribution system in a part of the defined territory for the purpose of its transmission to electricity consumers.

Electricity market participant
Electricity Producer, Transmission system operator, Distribution system operator, Electricity Supplier, Electricity Consumer, Short-term Electricity Market Organizer.

Electricity market rules
Ordinance of the Regulatory Office for Network Industries No. 24/2013 Coll. determining the internal electricity market rules and internal gas market rules.

Electricity price
It is calculated as share of sum of all payments for used electricity and the used amount (EUR/kWh). Usually composite prices (tariffs or tariff systems) are used comprising of constant factor (independent from the amount of used electricity, i.e. payment for max. power off-take) and variable factor (dependent on volume of used electricity). Various customers can principally pay different price for the same amount of electricity. The price depends on tariff and off/take nature/process. The average price of electricity for producers and distributors is calculated as share of sum of total production costs or purchase price plus fair profit and the amount of supplied electricity.

Electricity producer
The entity that is authorized to produce electricity.

Electricity purchase
Records the flow of electricity among subjects doing business in energy sector, i.e. producers, distributors and electricity dealers.

Electricity supplier
A natural or legal person authorized to supply electricity.

Electricity transmission
The transport of electricity on the transmission system in the defined territory, or the transport of electricity on the transmission system from and to the interconnected transmission systems of Member States of the European Union or to the territory of third states.

Eligible customer of electricity
A natural or legal person who is entitled to choose the supplier of their electricity.

EIC Local Issuing Office
TSO, which is on defined territory authorized by European Network of Transmission System Operators for Electricity (ENTSO-E) to assign and keep records of identification numbers (ID) of subjects of settlement and balancing groups according to ENTSO-E standard. EIC local issuing office defines process for assigning identification numbers of delivery points according to ENTSO-E standard. Such IDs are issued by TSO, which is in Slovakia SEPS, a.s.

Energetic week
Seven following trading days start on Saturday at 00:00:00 hour, and finish on Friday at 24:00 hour.

Export of electricity
The flow of a contractually agreed quantity of electricity from the defined territory to a European Union Member State or a third state.

External Market Operator
External company organizing the market in defined trading area, which is a partner of OKTE, a.s., in the process of Market coupling.

Imbalance Biller
Legal entity providing imbalance billing among contractually agreed and actual values of electricity provided in specified time. OKTE, a.s., is the Imbalance Biller.

Imbalance of Electricity Market Participant
Imbalance originating in a certain time frame as difference between contractually agreed volume of supply or consumption of electricity and supplied or consumed volume of electricity in real time (see Energy Act).

Imbalance period
Basic evaluation and settlement period of imbalance and regulation electricity. The basic period is quarter of a trading hour.

Import of electricity
The flow of a contractually agreed quantity of electricity from a European Union Member State or a third state to the defined territory.

Kilowatt-hour
Unit of expended active energy means conjunction of active energy and time. 1 kilowatt-hour is the amount of energy used by a 100 W light bulb in 10 hours or a heat storage stove powered by 3kW in 20 minutes.

Market coordinator
Entity (possibly part of the information system) coordinating cross border exchanges of electricity among cooperating trading areas.

Market coupling
Principle of integration of two or more trading areas.

Offtake model diagram
Offtake diagram is identical for a given group of electricity customers.

Over costs
The difference between the total cost of regulating electricity in the business hour concerned and the product of the system imbalance and the settlement electricity price.

Quarterhourly accrual of the trading hour
Sequence of four consecutive time intervals lasting 15 minutes. If the given value applies to full trading hour, quarterhourly accrual means succession of four identical values which in total represent the given value.

Regulation electricity - RE
Electricity provided by Transmission System Operator in order to balance the production and consumption of electricity on defined territory including the import and export of electricity.

Regulatory Office for Network Industries
Established in 2001 for state regulation for network industries - production, purchase, transmission and distribution of electricity, gas, heat, production and supply of drinking water, disposal and cleaning of waste water. Those are industries where natural competition is missing and there is a risk of abusing the dominant position of producers and suppliers on the expense of consumers.

RE Supplier
The provider of ancillary services or supplier of unguaranteed regulating electricity that concluded a general agreement on provision of ancillary services and supply of regulating electricity and/or a general agreement on supply of unguaranteed regulating electricity with Transmission System Operator.

Resinous imbalance
Imbalance is marked resinous (-) if subject to clearing causes surplus of electricity in transmission system.

Resinous regulation electricity
Electricity balancing the resinous imbalance in transmission system meaning either lower production or higher consumption of electricity.

Short-term organized market participant
Subject of Settlement that signed the Agreement on daily market access and/or other markets organized by OT.

Spot/Area price Market
Clearing price - price achieved in individual time intervals in the process of order matching.

Subject of Settlement
An electricity market participant that chose the regime of its own responsibility for imbalance and signed the Agreement on Settlement of Imbalance.

Subject of Settlement
An electricity market participant that chose the regime of its own responsibility for imbalances and made an agreement on Settlement of Imbalance.

System imbalance
The sum of all individual imbalances by the subjects of settlement for a given trading period.

Vitreous imbalance
Imbalance is marked vitreous (+) if Subject of Settlement causes lack of electricity in transmission system.

Vitreous regulation electricity
Electricity balancing the vitreous imbalance in transmission system meaning either higher production or lower consumption of electricity.

Trading area
The area on which OKTE, a.s. organizes and evaluates the organized Short-term cross-border electricity market for participants of the organized Short-term cross-border electricity market.

Trading day
24 trading hours except for the transition of the trading day from the Central European Time to the Daylight Saving Time and back; it starts with the first trading hour at 00:00:00 and finishes at 24:00:00. By transition to the Daylight Saving Time is Trading day 23 trading hours and by transition to the Central European Time is Trading day 25 trading hours.

Trading hour
Basic time frame for which electricity delivery or off-take is agreed. First trading hour of the trading day starts at 00:00:00 and ends at 01:00:00. It is marked by Nr. 1.

Transmission system
The system of interconnected electricity lines and electricity facilities necessary for the transmission of electricity and the system of interconnected electricity lines and electricity facilities necessary for interconnection of the transmission system with a system outside of the defined territory; the transmission system also includes the metering, protection, control, security, information and telecommunication equipment necessary for the operation of the transmission system.

Transmission System Operator (TSO)
A legal person authorized to transport electricity in a part of the defined territory according to the Act on Energy. SEPS, a.s., is the Transmission system operator in Slovakia.

Transmission system operator - TSO
A legal person authorized to transport electricity in a part of the defined territory. SEPS, a.s. is the Transmission system operator in Slovakia.

Valid currency
Since January 1, 2009 the valid currency is Euro (EUR).

Wholesale customer of electricity
A natural or legal person who purchases electricity for the purpose of resale, and who is license holder to supply electricity on Act No 656/2004 Z. z.