Grid Code

This Regulation regulates the requirements applied to the security of supply of electrical power systems and the technical requirements for electrical installations arising from security of supply. This Regulation prescribes the requirements for the connection of electrical installations to the power network and the rights and obligations of the market participants related to balance responsibility.

(1) For the purposes of this Regulation, “system protection automation” means automatic equipment intended for ensuring stable operation of a system and the prevention of system blackout. Automatic equipment by which the production capacity or power consumption of a market participant is changed on the basis of an agreement between the system operator and the market participant and electrical equipment of the market participant is switched on or off as required is not deemed to be system protection automation.

[ RT I 2007, 37, 255 - entered into force 25.05.2007]

(1¹) For the purposes of this Regulation, “wind turbine” means production system, which converts kinetic wind energy into electric energy.

[ RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) For the purposes of this Regulation, “reliability of a power system” means the ability of the power system to ensure joint operation of power plants and power networks in the operation of the power system.

(3) For the purposes of this Regulation, “excitation system ceiling voltage” means the maximum DC voltage which the excitation system is able to provide from its terminals under the defined conditions.

(4) For the purposes of this Regulation, “generator” means equipment, which converts kinetic energy into electric energy.

(5) For the purposes of this Regulation, “generator circuit-breaker” means the circuit-breaker, which operates at the level of generator voltage or generator-transformer high voltage.

(6) For the purposes of this Regulation, “local load” means the load of a substation or a group of substations in up to 110 kV network located within a limited area near a fault location.

(7) For the purposes of this Regulation, “overspeed protection” means protection, which stops the wind turbine in case of too strong wind.

(8) For the purposes of this Regulation, “measuring point” means a place where the electricity which passes the place is measured.

(9) For the purposes of this Regulation, “measuring system” means a set of measuring devices and accessories intended for determining the amount of parameters of electrical energy consumed from the network or supplied into the network.

[ RT I 2007, 37, 255 - entered into force 25.05.2007]

(10) For the purposes of this Regulation, “ N-1” means emergency switching off of one element.

(11) For the purposes of this Regulation, “ N-1-1” means emergency switching off of one element while another element significantly influencing the reliability of the system is in maintenance.

(12) For the purposes of this Regulation, “ N-2” means emergency switching off of two elements.

(13) For the purposes of this Regulation, “ N-X” means emergency switching off of more than two elements.

[ RT I 2007, 37, 255 - entered into force 25.05.2007]

(14) For the purposes of this Regulation, “rated active power” means the rated active electrical power of a power plant generator or the sum of the rated active electrical powers of generators.

(15) For the purposes of this Regulation, “area” means the supply area of 220 kV or 330 kV substations in the northern, southern, western, or eastern parts of Estonia.

(16) For the purposes of this Regulation, “fault” means the state of a power system, which may cause disturbances in a power system or the electrical installations connected to it.

(17) For the purposes of this Regulation, “system blackout” means an emergency situation caused by voltage loss in the system.

(17¹) For the purposes of this Regulation, “consumption site” means a connection point of the electrical installation of a market participant or a set of connection points which are electrically connected with each other through the electrical installation of the market participant.

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

(18) For the purposes of this Regulation, “consumption conditions” means the voltage system, the throughput capacity of network connection in amperes or the maximum permissible power of power supply in kilowatts, the permissible duration of power supply interruption or power supply restoration time, the location of the connection point and the location of the measuring point or points.

[ RT I 2007, 37, 255 - entered into force 25.05.2007]

(18¹) For the purposes of this Regulation, “production conditions” means the voltage system, the production capacity, the permissible duration of power supply interruption or power supply restoration time, the location of the connection point and the location of the measuring point or points.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(19) For the purposes of this Regulation, “wind farm” means a power plant consisting of several wind turbines and the devices connecting wind turbines to each other and to the connection point, and the buildings and structures.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(20) For the purposes of this Regulation, “interconnected system” means a power system or a connection of power systems, with which the Estonian system operates on synchronous frequency.

(20¹) For the purposes of this Regulation, “European product certificate” means a document confirming compliance of the generating installation with the applicable European certification requirements.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(21) The power engineering definitions used in this Regulation and not specified in subsections (1) to (20) of this section shall be interpreted in accordance with the common practices of electrical power engineering.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) The unity and operational capacity of a system must be maintained in the event of a disturbance. It is more important to maintain the supply security of the system as a whole rather than to maintain the security of supply of one area.

(2) Upon planning the operation and development of a system it shall be taken into account that the more common disturbances N-1 and N-1-1 should not cause deviations of voltage, frequency or other values from the standards, extensive supply interruptions or loss of system stability.

(3) Electrical energy may be imported and exported or transited via a transmission network in quantities and on conditions, which do not reduce the reliability of the system, do not cause additional limitations to domestic consumption or decrease consumer supply security and the quality of energy in the whole system.

(4) During a disturbance and in a situation caused by a disturbance, the reliability and security of supply of the system and its parts can be smaller than usual if it is necessary for the localization or liquidation of the disturbance, or for the restoration of consumer supply. Upon the development and operation of a transmission network the system operator shall take into account that the supply interruptions caused by faults shall not exceed the indicators specified in the quality requirements for network services.

(1) A producer shall provide a guarantee to the network operator concerning the reliability of generating installations. This shall be expressed in the contract by the number of planned outages, the number of expected outages and the duration of outages.

(2) A network operator or a seller designated thereby shall present the requirements for the security of supply and the information concerning the duration of the planned interruptions and the expected interruptions in the contract concluded with the consumer and the producer.

(1) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(2) The capacity of the generating installations in the system shall meet the consumption demand of the system or a part thereof after the operation of system protection automation and ensure the required level of short-circuit currents.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(3) Subsections (1) and (2) of this section apply to normal operation, N-1 disturbances and non-receipt of the planned electricity.

(4) A system shall have sufficient reserves for securing the operational capacity of the system in emergency situations.

(5) A system operator is entitled to manage the power supplied by the generating installations to the extent of the technically possible reserve of the installations, if this is necessary for ensuring the security of system supply and the performance of international agreements.

(1) The normal operation of a system shall be statically and dynamically stable.

(2) In order to guarantee static stability, the static stability margin of generators shall be at least 20% in normal operation and at least 8% in the restorative state. The stability margin factor of the generator is calculated by using the following formula

where P0 - active output power of the generator,

Pmax - peak value of load angle characteristic of the system connected to the generator.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(3) A network operator shall ensure the static stability of the connection lines of the parts of electrical network by active load. The margin factor is calculated on the basis of active load by using the following formula

where Pmax - active power corresponding to static stability limit of the connection,

P - active load passing through the connection,

ÄP - peak value of irregular oscillations of active load in the connection in the given mode.

(4) The static stability margin factor, calculated by active load in the connection line shall be at least 20% in normal operation and 8% in the restorative state.

(5) A network operator shall guarantee static stability by voltage in the nodes of the electrical network and consumer connection points. The margin factor by the voltage is calculated by using the following formula

where Ukr - voltage corresponding to the static stability limit of the given load node,

U – load node voltage.

(6) The static stability margin factor calculated by voltage shall be at least 15% in normal operation and 10% in the restorative state.

(1) Electricity undertakings shall apply measures providing security of supply at the request of the system operator.

(2) In order to guarantee security of supply of the system or part of the system, the system operator may, in emergency situations, switch off consumption in the technically required amount.

(1) If frequency decreases in a power system as the result of a disturbance, the load-shedding protection must operate to guarantee the balance between consumption and production.

(2) If more than one element of the system trips from the power system as the result of some uncommon severe or other disturbance, the loss-of-the-voltage protection may operate to avoid voltage collapse; the protection may switch off up to 80% of consumption in one or several areas.

(3) If an interconnected system or a system operating in parallel with other systems deviates from the rated value of frequency more than 1.0 Hz, the system protection automation or system operator may disconnect the system from parallel operation.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) After system blackout the system shall be restored in accordance with the instructions prepared by the system operator.

(2) In case of tripping from the network, the generating installations must be able to operate for the supply of auxiliary load

(1) Tripping of one element is permitted if it does not cause the interruption of consumer supply in the entire area or the operation of the system protection automation

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) A system operator shall eliminate a system disturbance within 30 minutes as of being informed thereof, if it is technically possible.

(3) Supply interruption involving an entire area is not permitted upon normal and maintenance operation.

(1) Tripping of two elements is allowed if it does not cause system blackout.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) In case of tripping of two elements switching off of consumption of one or several areas or 80% of the whole consumption of the system is permitted.

(3) In case of tripping of two elements local supply interruption is permitted upon normal and maintenance operation.

(4) Upon normal system operation 80% of the consumer supply of the area may be interrupted if system protection automation operates in this area.

(5) The supply of the entire area may be interrupted in case of planned maintenance.

(6) The supply of several areas must not be interrupted at the same time upon normal or maintenance operation. In these cases, the operation of the system protection automation is permitted.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) As a result of the disturbance of more than two elements, the entire system may lose stability and fall into independent parts, and cause full supply interruption in some area.

(2) For the elimination of disturbances mentioned in subsection (1) of this section, the system operator shall prepare a detailed plan prescribing restoration of the integrity and supply security of the system. The system operator shall install system protection automation devices in order to avoid blackout of the entire system as a result of disturbances.

The system reliability criteria are presented in Annex 1.

(1) System adequacy means the ability of a power system to guarantee the balance between power consumption and production by taking into account the planned interruptions and permitted disturbances of system components.

(2) System adequacy reserves are calculated by using the following formula

where

Pvaru – system adequacy reserves;

Pinst – net power installed in the system;

Pimp– power which can be imported according to the estimate of the system operator;

Pmittekasut – power which cannot be used, if the need arises.

This power includes

1) power plants with a random production cycle, in particular wind turbines and combined plants operating only by heat load;

2) generating installations not used due to environmental restrictions;

3) conserved (start-up time over 168 hours) generating installations;

4) generating installations not used due to fuel restrictions or unused net power;

Prekonstr– generating installations not used due to reconstruction or scheduled repairs;

Pavarii – generating installations which cannot be used due to unscheduled interruptions/repairs;

Psüsteemiteen – reserves at the disposal of the system operator (e.g. emergency reserves);

Peksp – power set out in binding (guaranteed) export contracts;

Ptipukoormus– estimate of the maximum net consumption of the power system including losses.

(3) Upon determining the system adequacy reserves the throughput capacity restrictions to export and import from adjacent systems fixed by the system operator and the dependence thereof on the transit passing the Estonian power system shall be taken into account.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) The system operator shall assess the production reserves required to meet the consumption demand proceeding from the requirement that the system adequacy reserves shall not be smaller than the maximum daily consumption (peak consumption), whereto 10% of reserves shall be added for guaranteeing power supply in case of unexpected load changes and long-term unscheduled production interruptions.

(2) In addition to the requirement specified in subsection (1) of this section, the system operator shall, upon assessing the production reserves required to meet the consumption demand, take into account the availability of the unit capacities of power plants, the scheduled and potential unscheduled interruptions, the production reserves of the transmission network required for system services, the connection contracts concluded with the producers and the electricity export and import contracts.

(3) The system operator shall be notified in advance of all the planned electricity export and import contracts.

(4) The system operator shall prepare an estimate of the maximum and minimum consumption and evaluate the potential difference between the base load and the peak load. The estimate of maximum consumption shall be prepared on the basis of the weather conditions characteristic of the period of the year.

(5) All electricity generating authorities shall submit the data specified in Annex 3 concerning the following 10 years to the system operator by 1 September for the evaluation of the system adequacy reserves.

(6) The system operator shall publish the assessment of the production reserves required to meet the consumption demand in January (maximum consumption) and July (minimum consumption) of the following 10 years on its website by 1 November each year.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(2) Connection of a power plant with rated power of over 1 MW to the system shall be approved by the system operator. The data specified in Annex 2 shall be submitted to the system operator.

(3) A bi-directional active and reactive energy meter with a remote reading device shall be installed for commercial measurement of electrical energy.

(4) The reactive power required for the operation of an asynchronous generator shall be balanced on site on the basis of the principle that the reactive power supplied to the network and consumed from the network shall be minimal. The permitted deviation of reactive power is +/-10% of the rated active power.

(5) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(6) For real-time measurement of the produced or consumed electricity at the power plant the producer shall install a bi-directional active and reactive energy meter with a load curve recorder and a remote reading device.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) The project of the electrical part of a power plant to be connected to the network shall be approved by the network operator.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) The following relay protection shall be installed to power plant generators

1) overload protection;

2) overcurrent protection;

3) overvoltage and undervoltage protection;

4) frequency protection (required at the rated active power of over 200 kW);

5) voltage unbalance protection;

6) anti-motoring and rotation overspeed protection (required at the rated active power of over 200 kW).

(3) The set points of relay protection shall be approved by the network operator to whose network the power plan will be connected.

(4) The generator shall be switched to the network with a synchronizing device, which prevents inrush. The generator can be switched to the network with an inrush if the current ratio does not exceed the values calculated by the following formulae

1) in case of a turbogenerator

2) in case of a hydrogenerator

3) the meaning of the symbols of the values in the formulae presented in clauses 1) and 2) is the following

IES Maximum value of the periodic component of asynchronous closing current calculated by the formula

IN Rated current of the generator Xd" Direct-axis sub-transient reactance of the generator XSUM Total reactance of the power system in the connection point, determined by the network operator UN Rated phase voltage

(5) If voltage is lost in the electrical network and the power plant trips from the network, the generators of the power plant may be switched back on after 5 minutes as of the recovery of network voltage. The generator may switch to the network automatically if the automation guarantees switching on without inrush.

(6) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(7) If the rated active power of a power plant exceeds 200kW, the producer shall send the results of the measurements of (gross) active and reactive power produced in the power plant and voltage in real time to the control centre of the service area of the network operator. For that purpose, the producer shall install the measuring devices on the generating installations in accordance with the connection contract.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(8) If rated active power of a power plant exceeds 200kW, the network operator shall send the results of the measurements of (net) active and reactive power and voltage to the control centre of its service area in real time. For that purpose, the network operator shall install the measuring devices in accordance with the connection contract. In case of wind turbines the network operator shall also send the same data to the system operator.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) In order to connect a power plant to the network, the project of the electrical part of the power plant to be connected shall be submitted to the network operator for approval. If the power plant is connected to the distribution network, the distribution network operator shall coordinate the project with the system operator.

(2) The generators of a power plant must be supplied with the following relay protection

1) overload protection;

2) overcurrent protection;

3) overvoltage and undervoltage protection;

4) frequency protection;

5) voltage unbalance protection;

6) anti-motoring and rotation overspeed protection.

(3) At a power plant with synchronous generators an automatic disconnection by frequency drop shall be installed, which enables to guarantee independent operation of the power plant.

(4) The network operator shall install a backup protection and a backup automatic disconnection to a point from the connection point towards the network.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(5) The set points of relay protection and automation shall be approved by the network operator, to whose network the power plant will be connected. The connectee shall submit the set points of relay protection and automation to the network operator before connecting a power plant to the network.

(6) Automatic excitation control and excitation boost shall be installed to a synchronous generator.

(7) The generator shall be switched to the network with a synchronizing device, which prevents inrush. The generator can be switched to the network with an inrush if the current ratio does not exceed the values calculated by the following formulae.

1) in case of a turbogenerator

2) in case of a hydrogenerator

3) the meaning of the symbols of the values in the formulae presented in clauses 1) and 2) is the following

IES Maximum value of the periodic component of asynchronous closing current calculated by the formula

IN Rated current of the generator Xd" Direct-axis sub-transient reactance of the generator XSUM Total reactance of the power system in the connection point, determined by the network operator UN Rated phase voltage

(8) A soft starting device shall be installed to asynchronous generators unless otherwise prescribed in the connection offer.

(9) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(10) The producer shall send the results of the measurements of (gross) active and reactive power produced in the power plant and voltage in real time to the control centre of the service area of the network operator and to the system operator. For that purpose, the producer shall install the measuring devices on the generating installations in accordance with the connection contract.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(11) The network operator shall send the results of the measurements of the supplied (net) active and reactive power and voltage in real time to the control centre of its service area and to the system operator. For that purpose, the network operator shall install the measuring devices in accordance with the connection contract.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(12) The network operator shall submit the results of commercial measurement of the previous month concerning the production of the power plants in its service area to the system operator by the 5th date of every month. For that purpose, the measuring devices shall be installed in the power plant in accordance with the connection contract.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(13) A power plant shall be able to participate in primary control. The dead band of the speed controllers of the turbines must not exceed ± 0.1 Hz.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) As a rule, a power plant is connected to the transmission network. The connectee shall submit the project of the electrical part of the power plant to the network operator for approval. If a power plant is connected to a distribution network, the distribution network operator shall coordinate the connection offer and the project of the electrical part of the power plant with the system operator.

(2) The generators of a power plant must be supplied with the following relay protection

1) external fault protection;

2) internal fault protection;

3) rotor earth fault and stator earth fault protection;

4) phase current unbalance protection;

5) stator or rotor overload protection;

6) frequency increase and frequency drop protection;

[RT I 2007, 37, 255 - entered into force 25.05.2007]

7) asynchronous operation protection;

8) failure protection for generator breaker, if the breaker has been installed.

(3) An automatic disconnection by frequency drop shall be installed to the generators of the power plant, which enables independent operation of the generator.

(4) If a power plant with rated active power of less than 30 MW is connected to the network, a backup protection and a backup automatic disconnection shall be installed to a point from the connection point towards the network.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(5) Depending on the connection point, the set points of relay protection and automation shall be approved by the distribution network operator or by the transmission network operator. The connectee shall submit the relay protection and automation set points to the network operator before connecting the generating installations to the network.

(6) An automatic excitation control and excitation boost shall be installed to a synchronous generator.

(7) The generator shall be switched to the network with a synchronizing device, which prevents inrush.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

1) in case of a turbogenerator

2) in case of a hydrogenerator

3) the meaning of the symbols of the values in the formulae presented in clauses 1) and 2) is the following

IES Maximum value of the periodic component of asynchronous closing current calculated by the formula

IN Rated current of the generator Xd" Direct-axis sub-transient reactance of the generator XSUM Total reactance of the power system in the connection point, determined by the network operator UN Rated phase voltage

(8) For measurement of the produced or consumed electricity at the power plant a bi-directional active and reactive energy meter with a load curve recorder and a remote reading device shall be installed.

(9) The measurement results of active and reactive power supplied to the network and voltage shall be sent to the system operator in real time. For that purpose, the relevant devices shall be installed in the power plant in accordance with the connection contract.

(10) The signals indicating the positions of circuit breakers shall be sent to the system operator in real time. For that purpose, the relevant devices shall be installed on the generating installations in accordance with the connection contract.

(10¹) A power plant shall be able to participate in primary control. The dead band of the speed controllers of the turbines must not exceed ± 0.1 Hz.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(10²) In addition to primary control, the power plants shall be able to participate in secondary control.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(11) The technical requirements for the generating installations of a power plant are presented in Division 2 of this Chapter.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) The following requirements apply to wind turbines and wind farms

1) the connection of a wind turbine to the distribution network shall be approved by the transmission network operator. The transmission network operator shall make the corresponding decision within 30 days after the receipt of the application;

2) the project of the electrical part of the wind farm shall be approved by the network operator. As a rule, the network operator makes the relevant decision within 30 days after the receipt of the application. If the circumstances require a more detailed inspection, the decision will be made within 60 days after the receipt of the application.

3) wind farms with the rated active power of over 10 MW shall be connected to the transmission network

(2) The following relay protection shall be installed to wind turbines

1) overload protection;

2) overcurrent protection;

3) overvoltage and undervoltage protection;

4) frequency protection;

5) overspeed protection.

(3) After the operation of voltage or frequency protection the wind turbine may be switched on again, if the voltage and frequency in the network have remained within the permitted limits for at least 10 minutes.

(4) In case of wind turbines with the rated active power of over 1 MW, a backup protection and a backup automatic disconnection shall be installed to a point from the connection point towards the network.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(5) The set points of relay protection and automation shall be approved by the network operator, to whose network the wind turbine will be connected.

(6) The automation devices of a wind turbine shall guarantee that the wind turbine is switched off, if the dead-ended feeder connecting the wind turbine with the system is switched off by relay protection.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(7) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(8) It must be possible to control the power variation speed of the wind turbines and of the wind farms to be connected to the transmission network in case of changes in wind speed. The requirements for control shall be laid down in the connection contract concluded between the network operator and the producer.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(9) The following requirements shall be applied to the control of active power of a wind turbine or a wind farm with the rated active power of over 200kW

1) the active power of the wind turbine or the wind farm shall remain within the limits prescribed by the transmission network operator, the permitted deviation is +/– 5%;

2) the limit of active power shall be controlled by one central signal. The limit value may be transmitted by an external signal by using the network frequency or the circuit-breaker or by other appropriate means;

3) control algorithms and set points shall be changed by remote control;

4) it shall be possible to reduce the active power output in case of quick curtailment at least to 20% of the rated active power within 2 seconds from the moment that the signal reached the wind farm control system. A wind turbine or a group of wind turbines can be switched off in order to achieve quick curtailment of active power output.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(10) The following requirements shall apply to the control of the reactive power of a wind turbine or a wind farm

1) the reactive power required for wind turbine operation shall be produced on site. The reactive power supplied to or consumed from the network must be minimal. The permitted deviation is +/-10% of the rated active power.

2) in case of network disturbances the network operator must have the possibility to control the reactive power output of a wind turbine or wind farm with the rated active power of over 200 kW in the whole extent of the technically possible reactive power reserve. Automatic control of reactive power may be necessary if switching on and off of the connected wind turbine or wind farm or the lines connecting the wind farm to the network causes inadmissible voltage fluctuations for the consumers;

3) reactive power output shall be controlled by voltage on the upper-voltage or low-voltage side of the wind turbine. In the latter case current compensation shall be used;

4) the reactive power output shall be controlled by one central signal;

5) control set points and algorithms shall be changed by remote control.

6) if reactive power is controlled by the system operator, the system operator shall pay the producer for reactive energy supplied to or consumed from the network on the basis of the applicable price list.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(11) For the measurement of the produced or consumed electricity at the wind turbine or wind farm a bi-directional active and reactive energy meter and a load curve recorder with a remote reading device shall be installed.

(12) If the rated active power exceeds 200 kW, the measurement results of active and reactive power supplied to the network and voltage shall be sent to the control centre of the service area of the network operator in real time. For that purpose, the appropriate measuring devices shall be installed to the wind turbine or the wind farm in accordance with the connection contract.

(13) The following special requirements shall be applied to wind turbines and wind farms

1) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

2) the remote control system must enable to switch the wind farm on and off the transmission network and to send there the position and fault signals and measurement results in real time (active and reactive power, current and voltage);

[RT I 2007, 37, 255 - entered into force 25.05.2007]

3) the data on wind speed measurement and the data specifying the state of the wind farm or wind turbine and the reason for tripping of the wind farm shall be sent from the wind turbine or wind farm connected to the transmission network in real time. For that purpose, the devices specified in the connection contract shall be installed in the wind farm;

4) the technical specifications and projects of the electrical part of the wind turbine or wind farm to be connected to the transmission network shall be approved by the transmission network operator before the commencement of the work. As a rule, the transmission network operator makes the corresponding decision within 30 days after the receipt of the documents. If a more detailed inspection of the documents is required, the decision will be made within 60 days after the receipt of the documents.

(14) If a wind farm is being built in stages, its conformity to the requirements may also be verified by stages, if technically possible.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(1) The network operator shall send the following remote measurement results concerning the power plant connected to its network to the system operator

1) in real time the sum of active and reactive loads supplied to power plants with the rated active power from 200 kW to 1 MW. The data concerning wind turbines shall be presented separately.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

2) in real time the active and reactive loads supplied to the network of a power plant with the rated active power of over 1 MW;

3) remote hourly reading data of the meters.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) The distribution network operator shall inform the system operator of the generating installations to be connected to the network and submit the technical data specified in Annex 2 required for the simulation of the system.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) The requirements specified in this division apply to power plants with the rated active power of over 5 MW. The requirements are applied also to wind farms with the rated active power of over 5 MW and power plants with the rated active power below 5 MW unless otherwise provided for in this Regulation.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) If a power plant participates in controlling frequency or preserving emergency reserve, the conditions for controlling the generating installations of the power plant, the reserves to be preserved and the terms and conditions for payment for the services shall be laid down in the relevant contract.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(2) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(3) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(4) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(5) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(6) In case of static excitation the value of the ceiling voltage must be at least twofold and in case of brushless excitation at least 1.6 times of the rated value of excitation voltage of the generator. Upon determining the ceiling voltage other requirements applied to voltage control shall also be taken into account.

(7) An excitation system must enable application of the ceiling voltage during 10 seconds. Upon designing an excitation system, it must be taken into account that the requirements to ceiling voltage shall be satisfied also during close network faults. In addition to automatic control, an excitation system shall enable to control the excitation current manually.

(8) A vibration damper shall be installed on the generator to improve the damping of oscillations of extremely low frequency (0.2-1.0 Hz) between the generator and the power system, and which can be switched off. It must be possible to limit the output signal of the damper and the settings of the limitation shall be adjustable.

(9) In addition to the voltage regulator and vibration damper the control system includes also protecting limiters and devices stabilising the reactive current.

(10) The limiters of the rotor and stator currents have an inverse time characteristic which enables generator overloading.

(11) In the normal state the voltage control shall be automatic. Different control means may be applied depending on the reactive power output or the power factor. The use of the control system shall be approved by the transmission network operator.

(12) The requirements specified in this section are not applicable to wind turbines and wind farms.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) If frequency varies between 49-51 Hz, the following requirements shall be applied to the generator

1) the generator must operate continuously at maximum admissible power within the network voltage range between 90-105% of normal voltage and at any frequency between 49-51 Hz;

2) at the frequency 50.3-51 Hz the admissible operation time is up to 10 hours per year and with the duration of 30 minutes maximum per case;

3) if the operation frequency is over 50.3 Hz, a certain power decrease is permitted, if the maximum active power of the generator can be restored when the frequency drops below this value. The system operator shall evaluate the drop.

(2) If frequency varies between 49-47.5 Hz, the generator under disturbance conditions must operate for 30 minutes within the voltage range between 95% of the minimum normal voltage and 105% of the maximum normal voltage. The output power must not decrease if the frequency drops to 49 Hz, and can decrease 15% when the frequency drops to 47.5 Hz. Application of additional measures is recommended to avoid the decrease of power output.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(3) If frequency is varies between 51-52 Hz, the generator under disturbance conditions must operate for 5 seconds in the network within the voltage range between 95% of the minimum normal voltage and 105% of the maximum normal voltage. The output power may decrease, if stable operation at full power can be restored when the frequency drops below 50.3 Hz.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(4) If frequency varies between 51-53 Hz, the generator isolated from the system must operate at significantly decreased power output within the voltage range between 95% of the minimum normal voltage and 105% of the maximum normal voltage for 3 minutes. The system operator shall evaluate the drop.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(5) If frequency drops under 47.5 Hz, the generator may be disconnected from the network. In this case, the generator must switch over to auxiliary load. The generator shall be disconnected with as long a time-delay as the equipment enables. The generator must be able to operate on auxiliary load for at least one hour. The requirement concerning operating on auxiliary load is not applicable to wind turbines, wind farms and asynchronous generators.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(6) Upon designing the control system it shall be taken into account that the equipment must not switch off as a result of fast frequency variations due to faults or commutations in the high-voltage network.

(7) If frequency exceeds 55 Hz, the power plant must be disconnected from the system.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(8) Within the frequency ranges, where stable operation of the generating installations without disconnecting from the system is required, the requirements for primary and secondary control shall be satisfied in accordance with § 26 unless otherwise specified in this section.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) If network voltage varies and forms 95-105% of the normal voltage, the following requirements shall be applied to the generator

1) the equipment must withstand continuous full load within the frequency range of 49-50.3 Hz and network voltage range of 90-105% of the normal voltage;

[RT I 2007, 37, 255 - entered into force 25.05.2007]

2) if the operation frequency is over 50.3 Hz, a certain power decrease is permitted, if the maximum active power can be restored when the frequency drops below this value. The system operator shall evaluate the reduction. The operation time within the frequency range of 50.3-51 Hz is 10 hours a year and one disturbance must not last more than 30 minutes.

(2) If a network disturbance occurs within the frequency range of 49.7-50.3 Hz, the generator must operate within the voltage range of 85-90% of the normal voltage for one hour. In this case the output power may decrease up to 10% of the full power.

(3) If the network voltage is 105-110% of the normal voltage, the generator must operate within the frequency range of 49.7-50.3 Hz for one hour. In this case the output power may decrease up to 10 % of the full power.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(4) The following requirements shall be applied in case of close network faults

1) a turbogenerator must withstand mechanically the high-voltage-side one-, two- and three-phase faults of the set transformer with and without earth;

2) the fault of the 330 kV line going out from the power plant shall be eliminated in 0.1 second. In exceptional cases the time for the elimination may extend to 0.37 seconds. If faults occur in 200kV and 11kV networks, they shall be eliminated in 0.6 seconds and in exceptional cases in 1 second. Such faults must not cause damages to power plant equipment.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(5) [Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(6) If the point of connection to the power network is located on the low-voltage side of the transformer connecting the power plant with the system, the generator and its auxiliary devices must withstand the following voltage variations caused by power network faults without switching off from the network

1) sudden drop of the generator voltage to 25% of the rated voltage for up to 0.25 seconds;

[RT I 2010, 48, 295 - entered into force 19.07.2010]

2) linear increase of voltage after voltage drop to up to 95% of rated voltage within 0.5 seconds;

3) keeping generator voltage steadily on the level, which is at least 95% of the rated voltage of the generator. In this case the power output may decrease up to 10% of the rated power.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(6¹) If the point of connection to the power network is located on the high-voltage side of the transformer connecting the power plant with the system, the generator and its auxiliary devices must withstand the following voltage variations caused by power network faults without switching off from the network

1) sudden drop of voltage in the connection point to 0 % of the rated voltage for up to 0.25 seconds;

[RT I 2010, 48, 295 - entered into force 19.07.2010]

2) linear increase of the voltage after voltage drop from 25% to 90% of the rated voltage within 0.5 seconds;

3) keeping voltage of the connection point steadily on the level, which is at least 90% of the rated voltage of the generator. In this case the power output may decrease up to 10% of the rated power.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(6²) Voltage protection may be designed on the basis of several criteria, if a power plant must withstand other types of disturbances occurring in the generator or in the network.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(7) A generator or a power plant must be disconnected from the system in case the synchronism is lost and can be disconnected if the voltage variations or their duration exceed the design value. A generator and its auxiliary devices must withstand voltage variations, which do not prevent safe switching over to auxiliary load after disconnection from the network.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(8) An excitation system shall be installed to a generator and a power factor shall be prescribed, which will enable to supply reactive power equal to the rated active power at the rated power and at the level of 70% of the rated voltage during 10 seconds. This requirement is not applicable to wind turbines and wind farms.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(9) The transformation ratio of the set transformer of the generator or the transformer connecting the power plant with the system and the auxiliary transformer of the power plant, its adjustability and voltage range and the excitation system of the generator shall be designed and adjusted on the principle that the generator should be able to

1) generate constantly reactive power, which on the generator voltage level is determined by the power curve of the generator or the power plant;

2) consume continuously reactive power within normal voltage range of the system, which on the generator voltage level is determined by the power curve of generator or the currents admissible for wind farm equipment.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(10) Provided that the stability is maintained, the generator must be able to consume reactive power continuously in the amount determined by the power curve of the generator and by the maximum admissible continuous operating voltage of the equipment laid down in the conditions of connection.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) The power plant must have speed controllers of turbines and the relevant control systems.

(2) In the situations described in subsections 22 (4) and (5) and subsections 23 (1)-(3) the power plant must switch safely over to auxiliary power supply. In this case, the generator supplies only the auxiliary devices of the power plant and the plant must operate at least for one hour. The requirement specified in this subsection is not applicable to wind turbines, wind farms and asynchronous generators.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(3) Disconnection from the system means splitting the system into smaller separately operating parts. Disconnected power plants enable to control the power in accordance with the orders of the system operator in order to restore the power system unity by resynchronisation.

(1) The producer shall verify regularly the conformity of the generating installations of the power plant to the requirements established by this Regulation, starting from the commissioning to the end of their utilisation period. The producer shall determine the frequency of verifications proceeding from the technical state of the system and notify the system operator thereof.

(2) Tests concerning the power network and generating installations shall be made for the commissioning of the generating installation and for verifying its compliance to requirements. The measurement results of tests concerning the generating installation shall be capable of assuring proven traceability. The tests concerning the network shall be agreed with the system operator. Upon agreement with the system operator the tests may be partially substituted by imitation on a calculation model. The tests shall last up to 12 months, unless agreed otherwise by the producer and system operator. The period may be extended, if testing could not be carried out for reasons beyond the control of the parties to the agreement.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(2¹) During an emergency or disturbance state of the electrical power system the controllability of the generating installation shall be in conformity with the control characteristics.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(3) The aim of the tests and measurements concerning the power network is

1) to check the generator operation in case of transient voltage dip caused by fault in the situations mentioned in § 23;

2) to determine the circumstances of transition to auxiliary load. This requirement is not applicable to wind turbines, wind farms and asynchronous generators;

3) to determine how the network operates at auxiliary consumption during one hour;

4) to check the conformity of the controllability of the generating installation to the control characteristics.

(4) The aim of the tests and measurements concerning the generating installation is

1) to determine the load curve on the PQ chart;

2) to check for steep changes in generator voltage;

3) to check the state of the vibration damper;

4) to determine overload circumstances.

(5) The dynamic characteristics of the steady state shall be determined by measuring. For that purpose, the set point of the voltage regulator of the generator disconnected from the network and operating without load shall be changed so that the voltage of generator bus-bars would change by 10%.

(6) The voltage shall be increased and decreased steeply causing the change of the generator output voltage from 95% to105% and from 105% to 95%of the rated voltage. In both cases the change of the generator output voltage shall comply with the following requirements

1) the generator output voltage must not be oscillating;

2) if voltage is increased to 90% within the abovementioned range, the time of voltage increase in case of static exciter shall be 0.2–0.3 seconds and in case of brushless exciter 0.2–0.5 seconds;

3) the upper limit of no-load overspeed shall be below 15% of the range.

(7) If voltage is decreased in the range from 90% to 0%, the time for voltage decrease shall be 0.2–0.8 seconds in case of brushless exciter.

(8) The requirements specified in subsections (5) - (7) of this section are not applicable to wind turbines, wind farms and asynchronous generators.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) Upon determining the start-up time of the generating installations of power plants participating in load control, it shall be taken into account that the start-up time from outage to full-load operation should be as short as possible. The start-up times from the outage of equipment are the following

1) in case of generating installation of thermal power plants from the cold state - up to 12 hours;

2) in case of gas-turbine units – up to 10 minutes;

3) in case of wind turbines and wind farms – up to 15 minutes in case of wind conditions which enable starting.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(2) The minimum continuous output power shall be as little as possible. The data on the minimum output power of a power plant block are the following

1) solid fuel fired power plant – 40% of the rated power;

2) hydroelectric power plants and gas turbines – 10% of the rated power;

3) wind turbines and wind farms – less than 10% of the rated power.

(3) If appropriate, the data specified in subsection (2) of this section may be used for determining the minimum output power of other types of equipment.

(4) In the normal state power shall be controlled in accordance with the agreement and the action plan prepared by the system operator as follows

1) the prescribed value of output power shall be given manually by a pre-setting, which shall be adjusted by a frequency-sensible controller or with turbine controller. The output power must comply with the requirements of § 27 of this Regulation;

2) if a power plant is used for frequency control, it shall be specified in a separate contract.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) If a power plant is used for primary and secondary control of active power, the system operator shall conclude a corresponding contract with the producer. Subsections (2) – (9) of this section shall serve as a basis for establishing the technical conditions in the contract.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(2) A power plant shall be able to participate in primary control. The dead band of the speed controllers of the turbines shall be adjustable between ± 0–500 mHz with the deviation of ± 10 mHz.

(3) The dead band of the turbines participating in primary control must not exceed ± 10 mHz; in case of non-participation in primary control the dead band level must not exceed ± 100 mHz. It must be possible to switch primary control on and off both from the transmission network and in the power plant.

(4) The following requirements shall be met for the operation of the equipment

1) in the normal and alert state the output power of the generator shall be changed to the prescribed extent and within the specified limits either manually or by an automatic control system;

2) the set point of the primary regulator (frequency regulator) shall be 50 Hz;

3) it shall be possible to disengage the dead band;

4) it shall be possible to adjust the regulator droop between 2–8%;

5) the frequency measuring accuracy shall be at least ± 0.01 Hz.

(5) The primary control range (primary reserve) of the generating installation shall be at least ± 5% of the rated power;

(6) The generating installation shall obtain the required primary reserve power within 30 seconds, whereas 50% of it within 10 seconds, and be able to maintain the primary reserve power for at least 15 minutes.

(7) A power plant shall transfer from the normal state into alert state, if the frequency variation speed exceeds 0.5 Hz in a second or if the frequency differs ± 0.5 Hz from the prescribed frequency.

(8) In the alert state power shall be controlled as follows

1) all the generating installations of over 1 MW shall participate in primary control. The function of primary control shall be started automatically by a frequency relay or any other frequency-sensitive device;

2) the primary reserve shall be at least ± 12.5% of the rated power; in the case of wind turbines the primary reserve shall be at least 12.5% of the rated power;

[RT I 2010, 48, 295 - entered into force 19.07.2010]

3) [Repealed - RT I 2010, 48, 295 - entered into force 19.07.2010]

(9) The range of secondary control shall be at least ± 5% of the rated power and it shall be possible to realise it within 2 minutes.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) The load in condensing power plants shall be controlled at the rate provided for load changing in subsections (2) and (3) of this section. The power of other equipment may be controlled on the basis of the provisions in subsections (3) and (4).

(2) The active power of the generators of an oil fired or gas fired power plant is controlled at a rate of at least 8% of the rated power per minute. At this rate the power must be controllable within the limits of 30% in the range of 40-100% of the rated power of the equipment. If the equipment enables it, the output power can be changed at the maximum rate even in case it is below 40% or over 90% of the rated power.

(3) The active power of the equipment of solid fuel fired plants is controlled at the rate of at least 4% of rated power per minute. At this rate the power must be controllable within the limits of 30% in the range of 60-100% of the rated power of the equipment. In certain cases, the change may be below 20%. If the equipment enables it, the power can be changed at the maximum rate even in case it is below 60% or over 90% of the rated power.

(4) The active output power of wind turbines and wind farms is controlled at the rate of at least 8% of the rated power per minute, if the wind conditions enable it. At this rate the power must be controllable within the limits of 30% in the range of 20-100% of the rated power of the equipment.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) In case of a system disturbance, a heat device operating on solid fuel must enable change of output power within the limits of up to 5% of rated capacity in the range of 50-90% of the rated power of the equipment. Half of the abovementioned power must be obtained in 10 seconds, if the equipment does not have a superheater, or in 30 seconds in case one superheater has been installed. If the device has more than one superheater, a delay is accepted due to time constant caused by the additional superheater.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) In case of a network disturbance the turbines with bleeding must enable the maximum condensation power during 15 minutes by directing thermal power to the condenser.

(3) If the use of the reserve agreed earlier does not restore the normal state of the power system, the system operator has the right to demand that the producers adjust their production to the consumption of the production area.

(4) The control of the power of the generating installations not specified in subsections (1) - (3) of this section shall, in case of system disturbances, meet the requirements specified in § 27.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) A system operator shall ensure balance cooperation in the interconnected system.

(2) Electrical energy may be imported from other power systems and exported to other power systems or transited via a network of a transmission network operator in quantities and on conditions, which do not damage the national power system, do not cause additional limitations to domestic consumption or decrease consumer supply security and the quality of energy in the national power system.

(3) The system operator shall ensure safe and reliable operation of the transmission network in the interconnected system.

(1) If a system operates in an interconnected system and if in accordance with the contract the operator of the interconnected system is assigned to organise the management of a part of the interconnected system, the contractual tasks concerning the organisation of the interconnected system will take precedence over the tasks concerning the organisation of the operation of the of system and the system operator shall execute the instructions of the operator of the interconnected system first.

(2) The technical problems connected with the stability of the power system operating in an interconnected system shall be solved by the system operator in cooperation with the operator of the interconnected system.

(3) Upon cooperation the system operator and the undertakings concerned of the neighbouring states shall meet the environmental requirements.

(1) The contingency reserve is intended for the replacement of unexpected outage of the production capacity or the transmission capacity. The distribution of contingency reserve between the power systems in an interconnected system shall be determined by the relevant agreements.

(2) The regulating reserve is intended for the provision of system balance.

(3) The system operator may purchase power reserves from the neighbouring power systems of the interconnected system. The purchasing costs shall be divided between the power systems of the interconnected system by mutual agreement.

(4) The amount and procedure for use of the regulating and contingency reserves of the system shall be determined by intersystem contracts.

(5) The procurement and use of the reserves between the systems shall be arranged by the system operator.

(1) In order to connect to the network a connectee shall submit to the network operator a connection application and the following data and documents

1) data specified in Annex 2 of this Regulation;

2) a copy of the decision concerning the detailed plan or design criteria, demonstrating that the electrical installation of the connectee complies with the land use and structural criteria of the plan or the design criteria. Data concerning all electrical installations located before the connection point shall be presented in the documents. A connection application for constructing a wind farm in a public body of water shall be accompanied by a building permit instead of the documents specified in this clause;

3) a copy of the decision made by a person specified in the Environmental Impact Assessment and Environmental Management System Act, to the effect that an environmental impact assessment had been conducted or that there was no need to conduct an environmental impact assessment;

4) documents demonstrating that the consumer wishing to connect to the distribution network has a legal right to use the registered immovable or structure in which the electrical installation of the consumer is located.

(2) The data and documents specified in clauses (1) 1) – 3) of this section are not required, if connecting to the low-voltage network or amending the consumption or production conditions does not result in building a new connection point or installation of an additional generating installation.

(3) In order to connect an electrical installation to the network or amend the consumption or production conditions of an existing network connection, the network operator shall issue a contract offer on the basis of the connection application, which shall include the terms and conditions provided for in § 87 of the Electricity Market Act, in particular

1) the location of the connection and measuring points;

2) the amount of the connection charge or the charge for the amendment of the connection conditions and the terms of payment of the charges;

3) the term for connection to the network or amending the consumption or production conditions and other conditions;

4) the conditions for the amendment and termination of the connection contract;

5) other conditions, which are in compliance with this Regulation.

(4) Connection to the transmission network can be made at the rated voltage of 110 kV or 330 kV.

(5) The network configuration and the technical parameters related to the connection to the network or the amendment of consumption or production conditions shall be determined by the network operator. Upon connecting an apartment building to the network or amendment of the consumption conditions of an apartment building, the network operator shall determine the technical conditions for the installation of measuring equipment.

(6) The apartment possessor shall coordinate the amendment of the consumption conditions of an apartment with the owner or possessor of the residential building, who shall, if necessary, submit a connection application to the network operator for the amendment of the consumption conditions of the residential building.

(7) The distribution network operator shall issue a connection contract offer within 30 days and the transmission network operator shall issue a connection contract offer within 90 days as of the receipt of the connection application unless agreed otherwise. If the offer of the distribution network operator is connected with the operations of the transmission network operator, the distribution network operator shall issue the connection contract offer within 30 days as of the performance of the relevant operation.

(8) The connection contract offer shall be valid for 60 days as of making the offer, unless agreed otherwise.

(9) A connection contract is deemed to have been entered into if the network operator receives an acceptance of the connection contract offer not later than on the last day of the validity of the offer and the connectee has submitted to the network operator the data and documents specified in this section together with the connection application.

(10) The deadlines for a connection contract to be concluded with the transmission network operator shall be the following

1) the first instalment under the connection contract shall be paid within 60 days from the conclusion of the contract. The first instalment constitutes 20% of the initial connection charge as agreed in the contract;

2) The second instalment constitutes 50% of the initial connection charge as agreed in the connection contract and shall be paid within 20 days from the announcement of the winner of the tender to build the connection point. The network operator shall issue an invoice to the client within five working days from the announcement of the winner of the tender;

3) The third instalment is made up of the remaining actual costs, less the amounts paid under clauses 1 and 2 of this subsection. The instalment shall be paid within 45 days from the completion of the connection point and the network operator shall issue an invoice to the client within 30 days from the completion of the connection point.

(11) A connection contract and a network contract may be concluded simultaneously.

(12) If the producer has not connected its electrical installation to the network in three years from the completion of the connection point the connection contract expires. The connection charges shall be returned to the connectee, less the costs incurred by the network operator in relation to the connection; and the released throughput capacity of the network shall be sold by public auction organised by the transmission network operator. The income derived from the auction shall be used to cover the costs incurred by the network operator upon building the connection point, with the remaining amount going to the connectee who owned the connection right. The costs of selling the connection point, constituting 5% of the initial connection charge, shall be deducted from the amount to be returned. In case the results of the public auction are not approved the market participants may submit connection applications to the network operator for taking up the released throughput capacity of the network.

(13) Upon the request of the connectee the network operator shall present to the connectee the technical conditions for the connection, including data concerning the expected connection charge, power plants connected to the electrical system and the throughput capacity of the power network, as well as other data concerning the state of the power network.

(14) The network operator shall present the following data on its website concerning the connection of a producer

1) the date of issuing and the term of validity of the connection offer;

2) the date of concluding and the term of validity of the connection contract;

3) the location of the connection point and connection voltage;

4) the name of the power plant;

5) the type of the power plant;

6) connection capacity;

7) the time of connecting to the network.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(1) In case the connection conditions are issued to a producer who uses a cogeneration installation of up to 5 MWel capacity (hereinafter referred to as the small cogenerator), the transmission network operator, when preparing a connection offer, or the distribution network operator, when approving a connection offer shall not take into account connection offers issued to other producers or production capacity for which connection contracts have been concluded, but whose connection to the power network as agreed in the contract or as known to the transmission network operator is intended to occur later than that stated on the installation of the small cogenerator.

(2) In case the connection of the installation of the small cogenerator affects the connection capacity of a producer who has already concluded a connection contract, the transmission network operator shall make additional capacity available for the small cogenerator. In this case the costs arising from early performance of the network development obligation by reason of the connection shall be included in the connection costs. The costs of performing the development obligation are not included in the connection charge, if the network operator had started executing the development obligation before the connection application was submitted. The final connection charge shall be determined in the connection offer.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

§ 322 Special rules for connecting power plants of up to 200 kWel capacity to the network

(1) In case the connection conditions are issued to a producer who uses a power plant of up to 200 kWel capacity (hereinafter referred to as the micro producer), the transmission network operator, when preparing a connection offer, or the distribution network operator, when approving a connection offer, shall not take into account connection offers issued to other producers or production capacity for which connection contracts have been concluded, but whose connection to the power network as agreed in the contract or as known to the transmission network operator is intended to occur later than that stated on the installation of the micro producer.

(2) In case the connection of the installation of the micro producer affects the connection capacity of a producer who has already concluded a connection contract, the transmission network operator shall make additional capacity available for the micro producer. In this case the costs arising from early performance of the network development obligation by reason of the connection shall be included in the connection costs. The costs of performing the development obligation are not included in the connection charge, if the network operator had started executing the development obligation before the connection application was submitted. The final connection charge shall be determined in the connection offer.

(3) Approval of the transmission network operator is not required for connecting an installation using renewable energy sources for production, whose capacity is less than 15 kW.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(1) The network operator shall calculate the charge for the connection to the network or for the amendment of the consumption or production conditions on the basis of the justified expenses incurred for that purpose. The connection charge or the charge for the amendment of the consumption or production conditions may be based on average costs. The network operator may use formulae including certain cost components for the calculation of the connection charge or charge for the amendment of consumption or production conditions.

(2) The total connection charge or the charge for the amendment of the consumption or production conditions shall not exceed the expenses incurred for the performance of connection contracts.

(3) The connection charge or the charge for the amendment of the consumption or production conditions includes the costs required for the connection of new consumption or production power or for the amendment of the existing consumption or production conditions, including the costs of the construction of new electrical installations and the reconstruction of the existing electrical installations.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) Unless agreed otherwise, in case of connection to the low-voltage distribution network (up to 1000 V) the connection point shall be located

1) in the connection board in the immediate vicinity of the registered immovable or on the registered immovable belonging to the connectee;

2) in the connection board installed next to the transit board of the cable network or in the switchgear of the substation located on the registered immovable or on the boundary of the registered immovable of the connectee;

3) in the connection board of the building.

(2) Unless otherwise agreed, in case of connection to the medium-voltage (over 1000 V) distribution network the connection point shall be located in the switchgear of a substation or on the pole of the overhead line.

(3) If the location of the existing connection point with the voltage below 1000 V is not specified by a document, the connection point shall be located

1) if supplied from an overhead line - on the first insulators from the power supply, which are located on the building or on a rising main. In this case the rising main and the insulators form part of the consumer's electrical installation and the connection terminals or binding bands belong to the network operator;

2) at the connection point between the cable forming part of the consumer’s electrical installation and the overhead line of the network operator. In this case the connection terminals or binding bands belong to the network operator;

3) in the transit board of the cable network or in the switchgear of the substation and the cable and cable lugs form part of the consumer’s electrical installation;

4) in the cable network – in the main board of an apartment building on the house-side terminals of the main fuse.

(4) In case of connection to the transmission network the connection point is located in the switchgear of the substation.

(5) A consumer of market participant, who does not need an activity licence for the provision of network service pursuant to subsection 22 (11) of the Electricity Market Act may connect to the transmission network only with the consent of the distribution network operator, in whose service area the electrical installation of the connectee is located.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

[ RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) The network operator shall provide the network connection in accordance with the connection contract if a valid contract concerning the use of the network connection has been concluded and there are no bases for refusal from the provision of the network service, in particular if the electrical installation of the connectee conforms to the requirements arising from the Electrical Safety Act.

[ RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) If the connectee puts the electrical installation into service for the first time or if the conditions of the consumption of the electrical installation are amended, the connectee shall submit the notice concerning the putting into service of the electrical installation prescribed in the Electrical Safety Act to the network operator, with whose network the electrical installation will be connected.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(1) If change of voltage system at low voltage (below 1000 V) is initiated by the network operator and the consumer wants to use the network services at the new voltage system, the consumer shall ensure conformity of his electrical installation and adjust it to the new voltage system. If the consumer does not want to change the voltage system, he has the right to use the network services of the previous voltage system.

(2) If change of voltage system at medium or high voltage level (over 1000 V) is initiated by the network operator, the consumer shall ensure conformity of his electrical installation and adjust it to the new voltage system and the network operator shall incur the justified expenses related to it.

(3) Change of voltage system on the consumer’s initiative means amendment of the consumption or production conditions.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

[Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

[Repealed – RT I 2007, 37, 255 – entered into force 25.05.2007]

(1) The network operator shall measure the electricity supplied to the consumer at the voltage below 1000 V as follows

1) if the fuse of the consumer’s connection point is up to 63 A, the measuring system shall enable to measure active energy in kilowatt-hours (kWh). From 1 January 2017 the measuring system shall enable to measure active energy by a remote reading device;

2) if the fuse of the consumer’s connection point is more than 63 A, the measurement system shall enable to measure active energy (kWh) unidirectionally. If necessary, reactive energy can be measured bi-directionally (kvarh). From 1 January 2013 the measuring system shall enable to measure active and reactive energy by a remote reading device. The requirement concerning the measurement of reactive energy does not apply to apartment houses or apartment associations where the final consumer is a residential client;

3) if the generating installation is connected to the network, the measuring system must enable to measure both active and reactive energy bi-directionally by a remote reading device.

(2) From 1 January 2017 the measuring system shall enable measuring active energy in apartments by a remote reading device.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(1) The network operator shall install a measurement system for the consumer of electricity at the voltage above 1000 V, which enables to measure active energy (kWh) and reactive energy (kvarh) bi-directionally. (2) From 1 January 2013 the measurement system referred to in subsection 1 of this section shall enable measuring energy by a remote reading device.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(1) The network operator shall install a measurement system for the producer with the net capacity of over 100 kW, which enables to measure with remote reading

1) active energy (kWh) bi-directionally;

2) reactive energy (kvarh) bi-directionally;

3) power (kW);

4) reactive power (kvar) bi-directionally.

(2) The network operator shall install a measurement system for the producer with the net capacity below 100 kW, which enables to measure active energy (kWh) bi-directionally with remote reading.

(3) The producer shall guarantee the measurement of the produced or consumed power by forms of energy.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) If the consumption of network services and electrical energy is measured in a place other than the connection point, the network operator shall determine the scope of the network services and the amount of consumed energy by a calculation.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) The calculation specified in subsection (1) of this section is based on the measured amounts of network services and energy, the network resistance between the measuring point and the connection point and the technical parameters of the electrical installations between the measuring device and the connection point.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(3) In apartment buildings the calculation specified in subsection (1) of this section is based on the amounts of network services and electrical energy measured in and between the connection point and the measuring points.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(4) The network operator, whose enterprise is at a higher level in the power system by its technical parameters, has the measurement obligation. In case of equal levels, the measurement obligation shall be determined by the system operator.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(5) A network operator may take tariff time switches into use, which can be evidenced to comply with the requirements of the standard EVS-EN 62054-21. The following constitute evidence

1) the producer’s declaration of conformity or

2) the conformity decision of a competent accredited calibration laboratory, accredited inspection or certification body.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(6) After the replacement of the supply element in the time switch or repair of the time switch, the network operator shall submit the tariff time switch for calibration in an accredited calibration laboratory. Among other things, a calibration certificate shall include the decision concerning the conformity or non-conformity of the tariff time switch to the precision requirement of the standard EVS-EN 62054-21.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(7) From 1 January 2013 a remote reading device shall enable the following

1) using the data communication network forward to the network operator, at least once every 24 hours, the measurement data registered during each trading period;

2) ensure access of a person agreed between the market participant and the network operator to the measurement data recorded by the network operator, referred to in clause 1 of this subsection.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(1) If necessary, the electricity measurement system of an apartment in an apartment building shall be replaced by the network operator, if electricity is sold directly to the possessor of the apartment.

(2) If the owner of a residential building wishes to start settling of accounts by one measuring system, he shall enable the network operator to remove the measurement system owned by the network operator.

(3) If the time limit for the calibration of the measurement system owned by the consumer has expired, the network operator shall replace the measurement system by a measurement system owned by the network operator at his own expense.

Chapter 7 [Repealed - RT I 2010, 16, 89 - entered into force 25.04.2010]

(1) A market participant may change the open supplier when the calendar month changes. The balance provider shall be notified of the change of the open supplier at least one month in advance.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) The balance provider shall submit the required information concerning the open supply chain to the system operator for balance settlement. If a new balance provider commences operation or if the balance provider of a market participant changes, the balance provider shall inform the system operator thereof.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(3) The system operator shall be notified of the change in supply chain at least 15 days prior to entry into force of the change. The system operator shall be informed of the change related to the measuring point determined by him.

(4) [Repealed - RT I 2010, 16, 89 - entered into force 25.04.2010]

A balance provider shall use means of communication, which enable the system operator to contact him twenty-for hours a day. The balance provider’s means of communication are the following

1) telephone

[RT I 2007, 37, 255 - entered into force 25.05.2007]

2) mobile phone;

3) e-mail;

4) fax.

(1) The balance provider shall forward information to the system operator in accordance with the provisions of the balance agreement and the orders of the system operator. The information shall be forwarded by electronic means unless otherwise provided by the balance agreement.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) The balance provider shall forward the system operator the information required for the provision and determination of the state balance.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(3) If the balance of the balance provider is unbalanced, the balance provider is required, at the request of the system operator, to indicate immediately how the balance will be provided. The balance provider shall, at the request of the system operator, commence activities which will balance its balance.

(4) The balance provider shall subscribe to sufficient power in order to satisfy the power demand of the market participants in its area of administration.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) Information shall be forwarded to the system operator in accordance with the provisions of the balance agreement and the orders of the system operator. The information shall be forwarded by electronic means unless otherwise provided by the balance agreement.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) The scope of the information to be forwarded in real time and planning data and the method of data exchange shall be agreed upon in the balance agreement by taking into account the special characteristics of the balance provider, the system operator and the data systems.

(1) The parties of fixed supply shall notify the open supplier and the balance provider of the agreed fixed supplies in accordance with the procedure established thereby at least one hour before the balance provider notifies the system operator of the fixed supplies affecting its balance.

(2) In case of cross-border fixed supply, the system operator and the institution concerned of the other party shall confirm that the supply is technically possible.

(3) The balance provider shall submit the following information to the system operator within the term prescribed in the balance agreement

1) the planned electricity production in the area of the balance provider. The production plans of the power plants of over 10MW and electricity generation installations of over 10 MW shall be presented separately in the electricity production plan;

2) total consumption in the connection points included in its open supply chain;

3) consolidated data concerning fixed supplies, which affect the balance of the balance provider. The balance provider shall notify the system operator of the fixed supplies concerning each trading period with the accuracy of 0.1 MWh.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(4) If balance providers submit different data on fixed supplies, the system operator shall notify them thereof immediately. Balance providers shall submit the data on all the fixed supplies to the system operator within the term prescribed in the balance agreement.

(5) The system operator shall forward the following information to the balance provider in real time

1) total consumption and production in Estonia;

2) information about the results of frequency measurements.

(6) An open supplier may request that producers the total capacity of whose generating installations exceeds 2 MW submit a daily consumption or production curve forecast by trading periods by the date prescribed by the system operator. The forecast shall include separate data on electricity generated from wind power.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(7) An open supplier may request that the market participants specified in subsection (6), who make errors in the same direction with the general forecast error, shall compensate for the loss caused to the open supplier by the forecast error in proportion to the absolute value of their forecast errors in the amount, which for a given market participant equals to the absolute value of the difference between the sales or purchase price of the balance energy of the forecasted period and the price of the energy fee for the electricity which has been purchased more or less from the open supplier or sold more or less to the open supplier in comparison with the forecast. Market participants shall not compensate for a forecast error regardless of the direction of error, if their open supplier does not have to compensate for the forecast error, including if a market participant made an error in the direction opposite to the one of its open supplier.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(8) If electricity is produced from renewable energy sources and the total capacity of generating installations exceeds 2 MW, the producer shall compensate for the forecast error in the amount equal to the absolute value of the difference between the sales or purchase price of one hour of balancing electricity and the average energy fee of the last calendar year of the seller specified in subsection 75 (3) of the Energy Market Act. If the total capacity of the generating installations is below 2 MW, the producer shall not compensate for the forecast error. This provision is not applicable to wind power.

(1) The accounting period which is the basis for the financial calculations related to balance is a calendar month unless agreed otherwise.

(2) The trading period is one full hour. The first hour of the day is time period 00.00-01.00 and the last hour is the time period 23.00-00.00.

(3) The aim of the balance settlement is to determine the electricity supplies between market participants. As a result of balance settlement the amount of open supply of a market participant in a trading period is determined. The balance of all market participants specified in the Electricity Market Act shall be determined by trading periods. In case of a distribution network operator, it is not necessary to determine separately its losses or the amount of electrical energy sold to market participants in order to perform the selling obligation prescribed in § 76 of the Electricity Market Act.

(4) The balance provider shall use the measurements from the boundary points for the balance of which it is responsible of and the measurement data provided by a network operator concerned.

(5) In order to settle the balance, electrical energy shall be measured by a period measurement device and fixed supplies shall be determined. Balance may be determined by using a combined method based on measuring and the use of type loading curves, if the value of the current of the main fuse of the connection point operating at low voltage does not exceed 63 A in a phase.

(6) Cross-border supply shall be determined by the relevant fixed supplies, which have been approved by system operators. Other cross-border electrical energy shall be deemed to be balancing electricity between system operators.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(1) For the settlement of the system balance, the amounts of the balances of the balance providers, the amounts sold and purchased between the system operator and undertakings concerned of the neighbouring states, and the amounts imported and exported through connection lines, shall be added up. The sum received must be zero.

[RT I 2007, 37, 255 - entered into force 25.05.2007]

(2) The system operator shall determine the amount of balancing electricity sold or purchased by the balance provider on the basis of the information submitted by the balance provider and the amounts sold or purchased between market participants included in the open supply chain of the system operator and the balance provider.

(3) An open supplier shall settle the balance of those market participants, for whom it acts as an open supplier.

(1) The following shall be submitted for balance settlement

1) initial information on balance settlement;

2) specified information used for the verification the initial information.

(2) If it becomes evident that initial information was not correct, the system operator together with the balance provider and other market participants shall establish the correct information to be used in balance settlement.

(1) The balance provider shall submit initial information to the system operator within 10 days as of the termination of the accounting period. The consolidated data concerning the open supplies based on measurements included in the balance provider’s balance are deemed to be initial information.

(2) If the balance provider and the system operator have agreed that the system operator shall receive information on the measured supplies directly from the network operators in the balance provider’s open supply chain, the balance provider shall not forward the relevant data of this network operator to the system operator.

(3) The information specifying the amounts of procurement and open supplies shall be submitted to the system operator within two months as of termination of the accounting period.

(4) In order to specify measured supplies, the balance provider shall, within the term prescribed in the balance agreement, submit to the system operator at the request of the latter the data being the basis for consolidated data, grouped by measuring points or by market participants.

(1) The system operator shall submit the following information on the trading period to the balance provider within the term prescribed in the balance agreement

1) the total amount of electricity procurements and supplies measured by the balance provider;

2) the total amount of fixed supplies of the balance provider, the data of which have been submitted to the system operator;

3) the transactions concluded during the trading period between the system operator and the market participants included in the open supply chain of the balance provider;

4) the amount and the price of balancing electricity of the balance provider.

(2) Final information shall be submitted to the balance provider within three month as of the termination of the accounting period.

(1) The balance provider shall organise the submission of the information required for the settlement of the balance to the system operator.

(2) The network operator shall submit the measurement data required for the balance settlement to the balance provider. The network operator shall submit the initial measurement results at least two days before the reporting date of the balance provider prescribed in the balance agreement. The network operator shall submit the final measurement results within one month as of the termination of the accounting period.

(3) The amount of the supply of an open supplier in the distribution network shall be calculated as the difference between the total amount of supply by readings of boundary meters of the distribution network and the supplies received from the distribution network operator, measured by other market participants in this service area of the distribution network operator.

(4) If the measuring point at the interconnection of networks is not located at the boundary of networks, the measuring data may be calculated. The difference between the calculated and the actually measured energy shall be determined after certain periods of time and compensated financially on the basis of the agreements between the network operators.

(1) The system operator is entitled to request the measurement data in the balance of the balance provider from the network operators, for whom the balance provider acts either directly or indirectly as an open supplier.

(2) The information concerning the mistakes detected in the measured supplies and fixed supplies shall be forwarded to market participants, whose balances have changed as the result of the correction of mistakes.

(1) The charge payable for the difference between the amount of electricity calculated by using a combination of measuring and type loading curves and the actual metered amount of electricity shall be calculated by using the weighed average price of electricity sold to the market participants during the year which was the basis for calculation.

(2) The seller who has sold electricity to a market participant shall submit data to the network operator concerning the amount and price of the electricity sold on the basis of a type loading curve within 10 days as of the termination of the time period specified in subsection (1).

(3) The network operator shall, within 30 days as of the receipt of the data specified in subsection (2), draw up a report based on the relevant data and measurement results, which serve as a basis for the settlements between the seller and network operator.

(1) If the open supply contract expires, the market participant using the open supply service shall conclude a new contract with another open supplier on the expiration date of the previous contract at the latest. A market participant shall notify the network operator to whose network its electrical installation is connected about the expiration of the open supply contract at least one month in advance.

(2) If the open supply chain is interrupted and the market participant does not conclude a new open supply contract, the network enterpriser to whose network his electrical installation is connected or the seller designated by this network operator is deemed to be his open supplier.

(1) For the balance settlement the system operator shall submit to a balance report the balance provider drawn up on the basis of the initial data forwarded to the system operator within 15 days as of the termination of the accounting period. The report shall include data on the amounts and calculated price of balancing electricity sold to balance providers and purchased from the balance providers in each hour.

(2) The system operator shall submit an invoice to the balance provider together with the balance report indicating the amount payable for the balancing electricity traded in the previous accounting period by the payment date indicated on the invoice. The amount payable is expressed as the difference between the amounts to be paid by the balance provider and the system operator for balancing electricity purchased from each other.

(3) If it becomes evident during final balance settlement that the amounts of balancing electricity differ from the amounts of balancing electricity determined initially due to which the amounts or price of the balancing electricity presented in the balance report shall be changed, the system operator shall submit a supplementary invoice to the balance provider within seven days as of the receipt of notification of the changes or the relevant sum will be offset in the next invoice submitted by system operator.

(1) The system operator has the right to demand guarantees from the balance provider, by which the balance provider ensures unconditional performance of the obligations assumed by the balance agreement.

(2) The guarantees are divided into permanent and variable guarantees. The amount of permanent guarantee of each balance provider is 31 955 euros. The amount of the variable guarantee shall be determined by the system operator in accordance with the subsections 20 (3)-(6) of the Electricity Market Act. The guarantee shall be provided by an Estonian bank or a bank belonging to the European economic space, which has an international credit rating to investment grade.

[ RT I 2010, 60, 407 - entered into force 01.01.2011]

(3) A balance provider shall submit the permanent guarantee for the prescribed date. The guarantee must be valid for at least four months after the expiry of the balance agreement.

(4) The balance provider shall transfer the variable guarantee to the special deposit account – guarantee account of the system operator. The balance provider shall cover the costs connected with the abovementioned transfer. The system operator shall not compensate to the balance provider for the costs connected with the money deposited on the guarantee account and the system operator shall return to the balance provider the interests paid by the bank to system operator for the money transferred to the guarantee account by the balance provider.

(1) The system operator shall verify the sufficiency of the guarantees on the basis of the information received in the course of balance settlement.

(2) If the balance provider transfers to the guarantee account an amount which is smaller than the one prescribed subsection 61 (4) of this Regulation, the system operator shall immediately notify the balance provider thereof and indicate the additional amount to be paid to the guarantee account of the system operator within 15 days as of the date the system operator became aware of the transfer of the smaller amount.

(3) The balance provider shall transfer the additional amount required by the system operator to the guarantee account of the system operator within the prescribed term.

(4) If the balance provider fails to provide the guarantee required by the system operator within the specified time limit, the system operator has the right to terminate the contract of balance responsibility by notifying at least 30 days in advance.

(5) The guarantee is released when the balance provider has performed the obligations to the system operator arising from the obligation to maintain balance or from the balance agreement.

The system operator shall disclose on its website the list of open suppliers, presenting the following data

1) name of open supplier;

2) official address and place of business;

3) numbers of means of communication;

4) commercial registry code;

5) unique identification code (EIC code) assigned to the open supplier.

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

(1) Only one supplier, who serves as the open supplier for the market participant in the meaning of subsection 44(1) of the Electricity Market Act can provide open supplies in one consumption site. In the case of fixed supply electricity can be purchased from several sellers simultaneously.

(2) A market participant can change an open supplier on the basis of a network contract concluded for a measuring point of a consumption site, provided the data specified in subsection 3 of this section are correct.

(3) If a market participant concludes a contract with a new open supplier, the open supplier shall present the following data to the relevant network operator at least 21 days before the desired change of supplier

1) identifier of the market participant: the personal identification code and the EIC code of the open supplier in case of a natural person; the commercial registry code and the EIC code of the open supplier in case of a legal person;

2) commercial registry code and EIC code of the new open supplier;

3) EIC code(s) of the measuring point(s) of the consumption site. The EIC code of a measuring point is based on a combination of symbols assigned to the network operator by the system operator. The network operator shall change the code of the measuring point, following the format established by the system operator, so that each measuring point has a unique EIC code.

4) the moment of changing the open supplier.

(4) Within five working days from receipt of the data referred to in subsection 3 of this section, the network operator shall check whether the conditions referred to in subsection 2 are met. If the conditions are not met, the supplier shall not change. The network operator shall notify the new open supplier immediately, whether the conditions have or have not been met; in case the conditions were met, the network operator presents to the new open supplier the data concerning the measuring point(s) in the format set out on the website of the system operator. The network operator shall immediately notify the current open supplier of the selection of the new open supplier.

(5) The open supplier shall change at the turn of the calendar month at 00.00 hours.

(6) In case electrical energy is measured by combining the period measurement device and type loading curves, the network operator shall fix the meter reading at the moment of changing the open supplier, by using the period measurement device and type loading curves. The reading shall serve as an end reading for terminating the current contract and start reading for the purposes of the new supply contract.

(7) In case electrical energy is measured by using a remote reading device the network operator shall fix the meter reading at the moment of changing the open supplier and the reading shall serve as an end reading for terminating the current contract and start reading for the purposes of the new supply contract.

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

(1) In case the consumer changes, the new consumer shall conclude a network contract and open supply contract with respect to the measuring point of its consumption site. One open supply contract and one network contract can be concluded per one consumption site.

(2) The open supplier shall submit to the network operator the data referred to in clauses 622 (3) 1)-3) and notify the network operator of the date of entry into force of the open supply contract.

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

(1) The open supplier shall give the network operator at least 21 days’ notice of changing the balance provider.

(2) The open supplier may change the balance provider at the turn of the calendar month.

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

(1) If, as a result of changing the service area of a network operator the location of the connection point of a market participant becomes part of the service area of another network operator, the network operator providing network services shall give at least 30 days’ notice thereof

1) to the open supplier, providing open supplies at the connection point which is the subject of the change of network operator;

2) to the market participant whose network operator is changing;

3) to the seller appointed by the network operator.

(2) From the moment of changing the service area the standard terms and conditions and network charges of the new network operator shall be applicable with respect to the market participant.

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

(1) The network operator shall disclose on its website the standard terms and conditions applicable upon termination before term of an open supply contract.

(2) In case the open supply contract of a market participant is terminated before term and the network operator is providing the market participant open supply services on the basis of subsection 44(41) of the Electricity Market Act, the network operator shall notify the market participant immediately, but not later than within two working days of learning about termination of the contract before term.

(3) Upon termination of the open supply contract before term the open supplier shall change on the day of termination, at 00.00 hours.

(4) In case after termination of the open supply contract before term a new open supply contract is concluded the open supplier shall change on the day following the conclusion of the new contract, at 00.00 hours.

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

(1) By the fifth date of each month the network operator shall provide the following data concerning the preceding calendar month to the open supplier of the consumption site

1) EIC code of the measuring point of the consumption site;

2) amount of electrical energy consumed from the network in each trading period;

3) amount of electrical energy supplied to the network in each trading period.

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

(2) Upon the request of the open supplier, every working day the network operator shall make available to the open supplier the initial data of the preceding day(s) specified in subsection 1 of this section for those measuring points which are measured by remote reading.

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

(3) The network operator shall present to the system operator the list of eligible consumers connected to its network. The system operator shall disclose the list of eligible consumers on its website.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(1) The system operator shall disclose the data exchange form and the description of data exchange on its website.

(2) The network operator shall disclose the e-mail address and telephone number required for data exchange between market participants on its website.

[ RT I 2010, 16, 89 - entered into force 25.04.2010]

(1) [omitted from this text]

(2) The requirements provided in Chapter 3 of this Regulation shall be applied to power plants put into operation or renovated before 1 July 2003 from 1 January 2016. Renovation of a power plant means reconstruction of a power plant resulting in significant changes in the operation of the power plant. The result shall be assessed by the system operator.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(3) The additional requirements provided in this Regulation shall be applied to power plants put into operation or renovated after 1 July 2003, by taking into account the Grid Code applicable at the time of concluding the connection contract, subject to agreement with the producer.

[RT I 2010, 48, 295 - entered into force 19.07.2010]

(4) The term of expiry of the contract, referred to in subsection 32(12) of this Regulation shall not apply to connection points completed before the entry into force of the Regulation.

[RT I 2010, 48, 295 - entered into force 19.07.2010]