On Electricity Grid Connections
20 July 2011
Agency for the Cooperation of Energy Regulators
Trg Republike 3
Ljubljana - Slovenia
This Document contains the Framework Guidelines on Electricity Grid
Connections, which the Agency for the Cooperation of Energy Regulators (ACER)
has developed pursuant to Article 6 of Regulation (EC) No 713/2009 and on the
basis of a request from the European Commission.
“Pilot Framework Guidelines on Electricity Grid Connections”, 7 December 2010, Ref: E10ENM-18-04.
“ERGEG Public Consultation on the Draft Pilot Framework Guidelines on Electricity Grid
Connection – Evaluation of Responses,” 7 December 2010, Ref: E10-ENM-18-04a,
“Pilot Framework Guideline on Electricity Grid Connection - Initial Impact Assessment”, 12
July 2010, Ref: E09-ENM-18-03, http://www.energyregulators.eu/portal/page/portal/EER_HOME/EER_CONSULT/CLOSED%20PUBLIC%20CO
“ERGEG Guidelines of Good Practice on Electricity Grid Connection and Access“, ERGEG,
10 December 2009, Ref. E09-ENM-16-04, http://www.energyregulators.eu/portal/page/portal/EER_HOME/EER_CONSULT/CLOSED%20PUBLIC%20CO
“Implementing the 3rd Package: next steps”, CEER/ERGEG, 18 June 2009, Ref. C09-GA-5206a, http://www.energyregulators.eu/portal/page/portal/EER_HOME/EER_PUBLICATIONS/CEER_ERGEG_PAPER
Directive 2009/72/EC of the European Parliament and of the Council of 13 July 2009
concerning common rules for the internal market in electricity and repealing Directive
Regulation (EC) No 713/2009 of the European Parliament and of the Council of 13 July 2009
establishing an Agency for the Cooperation of Energy Regulators. http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2009:211:0001:0014:EN:PDF
Regulation (EC) No 714/2009 of the European Parliament and of the Council of 13 July 2009
on conditions for access to the network for cross-border exchanges in electricity and
repealing Regulation (EC) No 1228/2003. http://eur-lex.europa.eu/LexUriServ/LexUri
Table of Contents
1 GENERAL PROVISIONS ...................................................................................................... 5 1.1 Scope ............................................................................................................................. 5 1.2 Application ...................................................................................................................... 5 1.3 Definitions....................................................................................................................... 5 2 MINIMUM STANDARDS AND REQUIREMENTS FOR CONNECTIONS ............................ 8 2.1 Standards and requirements applicable to all significant grid users .............................. 8 2.1.1
Connection of/to distribution networks
Connection regime for specific significant grid users
Special requirements on significant grid users for critical grid situations
2.2 Derogations .................................................................................................................. 10 2.3 Adaptation of existing arrangements to the network code(s) ....................................... 11 2.4 Compliance testing, compliance monitoring and enforcement ..................................... 11 3 PROMOTING (REAL-TIME AND OTHER) EXCHANGE OF INFORMATION BETWEEN
PARTIES AND IMPROVED COORDINATION .......................................................................... 13 3.1 General information ...................................................................................................... 13 3.2 Real-time information sharing ...................................................................................... 13 3.3 Specific provisions for information and communication between TSOs and DSOs ..... 14 4/14
These Framework Guidelines aim at setting out clear and objective principles for the
development of network codes pursuant to Article 6(2) of Regulation (EC) No 714/2009 (the
The network code(s) developed according to these Framework Guidelines will be applied by
electricity system operators and significant grid users, taking into account possible public service
obligations and without prejudice to the regulatory regime for cross-border issues pursuant to
Article 38 of Directive 2009/72/EC and of the responsibilities and powers of regulatory authorities
established according to Article 37(6) of Directive 2009/72/EC.
The network code(s) developed according to these Framework Guidelines will be evaluated by
ACER, taking into account their degree of compliance with these Guidelines and the fulfilment of
the following objectives: maintaining security of supply, supporting the completion and
functioning of the internal market in electricity and cross-border trade, including delivering
benefits to the customers and facilitating the EU’s targets for penetration of renewable
The network code(s) developed according to these Framework Guidelines shall apply to grid
connections for all types of significant grid users already, or to be, connected to the transmission
or distribution network.
Any grid user not deemed to be a significant grid user shall not fall under the requirements of the
The network code(s) developed according to these Framework Guidelines take precedence over
the relevant national codes and international standards and regulations. Where there are proven
benefits, and if compatible with the provisions in the European network code(s), national codes,
standards and regulations which are more detailed or more stringent than the respective
European network code(s) should retain their applicability.
The European Network of Transmission System Operators for Electricity (hereafter referred to as
ENTSO-E) shall ensure coherence and compatibility of the grid connection network code(s) with
provisions contained in the Framework Guidelines on System Operation.
For the purpose of these Framework Guidelines, the definitions contained in Article 2 of EU
Directive 2009/72/EC and in Article 2 of the Electricity Regulation apply.
Regulation (EC) No 714/2009 of the European Parliament and of the Council of 13 July 2009 on conditions for
access to the network for cross-border exchanges in electricity and repealing Regulation (EC) No 1228/2003.
Within that context, the terms ‘network’ or ‘grid’ refer to both transmission and distribution.
Moreover, the following definitions apply:
Ancillary Services – services necessary to support transmission of electric power
between generation and load, maintaining a satisfactory level of operational security and
with a satisfactory quality of supply. The main elements of ancillary services include
active and reactive power reserves for balancing power and voltage control. Active power
reserves include automatically and manually activated reserves and are used to achieve
instantaneous physical balance between generation and demand. Further elements of
ancillary services may include black start, inertial response, trip to houseload, spinning
reserve and islanding capability. In the liberalised market, many ancillary services are
contracted by Transmission System Operators from selected grid users that qualify for
providing these services.
Compliance Monitoring – the process for verifying that the (technical) capabilities of
significant grid users are maintained.
Compliance Testing – the process of verification that significant grid users’ installations
comply with the specifications and requirements provided for grid connection, for example
before starting operation of new installations. The verification should include, inter alia,
the revision of documentation, the verification of the requested capabilities of the new
facility by practical tests and simulation studies and the revision of actual measurements
during trial operation.
Grid Users – all users connected to the transmission or distribution grids.
New Grid Users – grid users not considered as pre-existing grid users.
Pre-existing Grid Users – grid users connected to the transmission or distribution grids
before the entry into force of the first release of the network code(s) developed according
to these Framework Guidelines.
System Operators – the Transmission System Operator (TSO) and the Distribution
System Operator (DSO), in their roles and responsibilities to implement and enforce the
relevant grid connection code(s).
Significant Grid Users – pre-existing grid users and new grid users which are deemed
significant on the basis of their impact on the cross border system performance via
influence on the control area’s security of supply, including provision of ancillary services.
DSOs are treated as grid users where they have to comply with the TSO`s requirements in the
network code(s). They are treated as system operators where they implement network code(s)
provisions with respect to significant grid users connected to the distribution system. Unless
stated otherwise, reference to DSO implies DSO as grid user.
Due to the close interrelationship between a number of issues related to grid connection and
system operation, the following criteria have been applied in deciding whether a specific issue is
dealt with in these Framework Guidelines or in the Framework Guidelines on System Operation:
Issues involving the active participation by grid users are addressed in these Framework
Issues affecting only system operators, with no role for grid users, are addressed in the
Framework Guidelines on System Operation.
Issues which are relevant both to grid connections and system operation, are as a
minimum mentioned in both Framework Guidelines and, where necessary, also specified
in more detail. Some redundancy might emerge from this approach, but priority has been
given to avoiding the omission of important aspects.
Minimum standards and requirements for connections
Standards and requirements applicable to all significant grid users
The network code(s) developed according to these Framework Guidelines shall define
appropriate minimum standards and requirements applicable to all significant grid users.
The minimum standards and requirements shall be defined for each type of significant grid
user and shall take into account the voltage level at the grid user’s connection point. The
network code(s) shall specify the criteria and methodology for the definition of significant grid
users. These shall be based on a predefined set of parameters which measure the degree of
their impact on cross-border system performance via influence on control area`s security of
supply, including provision of ancillary services ("significance test"). This process, undertaken
by each individual TSO and reviewed by the respective National Regulatory Authority (NRA),
shall require coordination with the adjacent TSOs and relevant DSOs.
The applicability of the standards and requirements to pre-existing significant grid users shall
be decided on a national basis by the NRA, based on a proposal from the relevant TSO, after
a public consultation. The TSO proposal shall be made on the basis of a sound and
transparent quantitative cost-benefit analysis that shall demonstrate the socio-economic
benefit, in particular of retroactive application of the minimum standards and requirements.
Where it is not demonstrated that the socio-economic benefits outweigh the costs of requiring
compliance, pre-existing (and, in exceptional cases, new) significant grid users can be
granted derogations. The format and methodology or principles of the cost-benefit analysis
shall be prescribed by the network code(s).
The "significance test" and cost-benefit analysis shall be performed by the TSO (grid users
shall provide the relevant data and offer their assistance if necessary).
The network code(s) shall provide for regular re-assessment (including public consultation) of
the “significance test” and cost-benefit analysis to cope with evolving system requirements
(e.g. penetration of renewable energy sources, smart grids, distributed generation, household
demand response, etc.).
The network code(s) shall define the physical connection point between the significant grid
user’s equipment and the network to which they apply. Furthermore, the network code(s)
shall define the requirements on significant grid users in relation to the relevant system
parameters contributing to secure system operation, including:
Frequency and voltage parameters;
Requirements for reactive power;
Load-frequency control related issues;
Requirements for protection devices and settings;
Fault-ride-through capability; and
Provision of ancillary services.
For avoidance of doubt, the network code(s) shall also contain all the necessary provisions
applicable to significant grid users that are connected to distribution networks, but that also
affect the transmission network, because, for example, they feed energy up to the
transmission grid or, given their operation mode and fuel type, they significantly influence the
need for reserve capacity.
The network code(s) shall set out how the TSO defines the technical requirements related to
frequency and active power control and to voltage and reactive power management.
Technical rules set at the synchronous system level for operational security shall be in line
with these requirements. Those rules shall be aligned as far as technically possible and
economically beneficial throughout the EU, irrespective of synchronous area borders.
Where the minimum standards and requirements, introduced by the network code(s), deviate
significantly from the current standards and requirements, there should be a cost-benefit
analysis performed by ENTSO-E that justifies this deviation and demonstrates additional
benefits from requiring the higher standard.
Connection of/to distribution networks
The network code(s) shall set out necessary minimum standards and requirements to be
followed by DSOs when connecting significant grid users to the distribution network.
For DSOs that are defined as significant grid users, the network code(s) shall set out
minimum standards and requirements for their equipment installed at the connection point
between the transmission and distribution system networks.
Regarding significant grid users connected to the distribution network, any requirements on
system operators for adaptation of existing arrangements (as defined in section 2.3, including
in respect of distribution network codes and connection agreements) and for ensuring that
distribution-connected significant grid users meet the requirements set out in the network
code(s) shall be the responsibility of the DSO.
The network code(s) shall specify a requirement on DSOs to execute (manually or
automatically, depending on the purpose) the instructions regarding distribution-connected
significant grid users given by the TSO. The TSO and the DSO shall agree how these
instructions are delivered in practice. This applies also for those DSOs connected to another
Connection regime for specific significant grid users
Where additional requirements beyond those defined in the minimum standards and
requirements are mandated for a particular class, technology, size or location of significant
grid user, the network code(s) shall set out and justify these additional requirements.
Where justified by technical conditions, the network code(s) shall foresee special provisions
concerning protection device setting for the large intermittent generation (e.g. wind,
Where specific electrical or geographical conditions require, additional national provisions
could be defined, beyond the provisions in the relevant EU network code(s). ENTSO-E shall
strive, in cooperation with the national TSO(s), to ensure compatibility of such national
provisions with the EU-wide network code(s).
The network code(s) shall set out the necessary requirements for protection and fault-ridethrough capability with particular focus on distributed generation because of its increasing
importance and contribution to meeting demand. These requirements shall aim at avoiding
e.g. a large disturbance in the transmission network resulting in mass tripping of distributed
The network code(s) shall set out necessary minimum standards and requirements to be
followed when connecting a consumption unit to the grid, to enable demand response and/or
participation of consumption units in other grid services, on a contractually-agreed basis. The
responsibility for the compliance of the features and performance of the equipment with the
requirements set by the TSO or DSO shall be with the consumption unit.
Special requirements on significant grid users for critical grid situations
The network code(s) shall define:
situations in general (e.g. which kinds of network faults, which electrical distance)
the detail of possible deviations of significant parameters (e.g. voltage, frequency) that
generation units must withstand, while remaining connected to the grid. Different
definitions may apply to different types of generation units.
The network code(s) shall define minimum conditions for (re)connection to the grid in
disturbed/critical operating state.
The network code(s) shall set out how generation units must be able to execute their control
activities in normal and in alert (disturbed) operating states. Specific parameters for operation
outside these operating states will be agreed bilaterally between generation units and system
Coordination requirements and procedures for reconnection after tripping shall be defined
transparently in the network code(s) for the different parties involved. The network code(s)
shall elaborate their different roles and responsibilities.
In particular for the following services the network code(s) shall set out the minimum
requirements for those generators providing them on a contractually-agreed basis:
House load operation including the minimum duration of house load operation;
Black start; and
The network code(s) developed according to these Framework Guidelines shall describe the
process and criteria for applying for derogation. This process is applicable to pre-existing
(and in exceptional cases new) significant grid users.
The derogation process shall be transparent, non-discriminatory, non-biased, well
documented and based on the cost-benefit analysis performed by the TSO.
The network code(s) may provide that derogation from all or some of the minimum standards
and requirements may be granted to classes of pre-existing (and, in exceptional cases, new)
significant grid users, non-discriminatorily, without the cost-benefit analysis being performed,
if the TSO submits to the NRA a reasoned request and the exemption from the cost-benefit
analysis is authorised by the NRA.
During the derogation application process the significant grid user shall be deemed as
The relevant NRA shall decide whether to grant a derogation or not, and whether to waive
the requirement for the cost-benefit analysis, based on the TSO`s proposal.
Each NRA shall maintain a register in which derogations are recorded, together with the
reasons for their granting, the consequences and whether the requirement for the costbenefit analysis has been waived. This information shall be communicated to ACER. ACER
shall monitor the granting of derogations and may request the relevant NRA to revoke any
derogation granted without due justification.
Adaptation of existing arrangements to the network code(s)
System operators and relevant significant grid users shall amend all relevant clauses in
contracts and/or relevant clauses in general terms and conditions relating to the connection
of the significant grid user to the electricity grid, in accordance with the terms of the network
code(s). The relevant clauses shall be amended within a fixed time limit after entry into force
of the network code(s), defined in the network code(s), but not exceeding three years. This
requirement shall apply regardless of whether the relevant contracts or general terms and
conditions provide for such an amendment. The detailed technical provisions for the
transition from the national to the EU network code(s) shall be further elaborated in the
The network code(s) shall provide for a transition period within which the relevant significant
grid users have to apply the new standards and requirements. The transition period shall be
consulted upon among relevant stakeholders. The network code(s) shall specify the
principles behind setting the transition periods for significant grid users. The system operator
shall be responsible for evaluating the applicability of these principles to significant grid users
and determining an appropriate transition period. The system operator shall take into account
significant grid users` class and any underlying obstacles for efficient undertaking of the
equipment modification/refitting. In general, the transition period should not exceed two
years. Different transition periods for compliance can be set for new grid users and for preexisting grid users and also for different minimum standards and requirements.
Compliance testing, compliance monitoring and enforcement
The network code(s) shall define clear and transparent criteria and methods for compliance
monitoring, including the requirements for compliance testing.
In particular, the network code(s) shall introduce an obligation for system operators regularly
to assess the compliance of generation units with the standards and requirements defined for
the connecting installation, including electrical safety.
New grid users defined as significant must provide evidence of compliance with
specifications and requirements before the responsible system operator allows for
connection. The system operator must define transparently the exact contents of the
compliance testing within the provisions of network code(s).
The network code(s) shall foresee the possibility of repeated compliance testing by the
system operator even after the significant grid user is connected to the grid.
The network code(s) shall specify which data from the actual operation of connected
installations should be used to verify compliance with the applicable minimum standards and
The network code(s) shall provide for regular monitoring of the alignment of EU and national
codes and provide for corrective measures if any discrepancies are detected.
The network code(s) shall always require the system operators to optimise between the
highest overall efficiency and lowest total cost for all involved stakeholders. In that respect,
NRAs shall ensure, that, whatever the cost-sharing scheme is, the cost split follows the
principles of non-discrimination, maximum transparency and assignment to the real originator
of the costs. Nothing in the network code(s) shall prevent commercial arrangements being
used for the provision of ancillary services.
Promoting (real-time and other) exchange of information between parties and
The network code(s) shall set out the procedures and requirements to coordinate and ensure
information sharing between:
TSO and TSO;
TSO and DSO; and
System operator and significant grid user.
These procedures and requirements shall be defined with the agreement of all affected
The network code(s) shall define a harmonised standard according to which information shall
be provided for grid connection at the connection point by TSO and DSO. Similarly, the
network code(s) shall define what information and technical data the significant grid user has
to provide to the TSO or DSO to which it is connected and how this data is to be provided to
ensure the operational security of the system.
The network code(s) shall contain provisions committing TSOs and DSOs to publish and
transparently communicate the detailed procedure for the initiation of new connection,
including, inter alia, required documents, timing, methodologies, responsibilities, etc. This
information shall also address the relevant grid access issues, which will be dealt with in
more detail in the future Framework Guidelines for grid access.
Information exchange between TSOs and DSOs about the commissioning of significant grid
users shall be framed on EU basis, through the coordination of the definition of significant
grid users2 in the “significance test”.
Real-time information sharing3
Information exchange provisions contained in network code(s) shall include sufficiently
detailed specifications for an efficient coordinated system with access to real-time
The network code(s) shall set the requirement for every significant grid user to be able and
obliged to provide the necessary real-time operational information to the DSO and TSO that
their connection has significant impact upon.
The network code(s) shall set the requirement for every significant grid user to be able to
receive and to execute the instructions sent by the TSO and/or DSO, on a contractual basis
or in critical operating state.
As indicated in Section 2.1.
Real-time information sharing refers to information which is also the subject of the Fundamental Electricity Data
Transparency comitology guidelines. The purpose here is different, i.e. the information is primarily used by the system
operators and not by market participants. The network code(s) shall take account of information already required as
part of the comitology guidelines, and only set out requirements for data information that go over and above this.
Moreover, real-time information is also relevant for Framework Guidelines on System Operation and will also be dealt
Specific provisions for information and communication between TSOs and
The network code(s) shall define the requirements for the interface between TSOs and
DSOs, such as:
voltage parameters; and
reactive power flow;
taking into account the situation with regard to significant grid users connected to the
The network code(s) shall set out that the TSOs of a synchronous area shall exchange,
among themselves and with the DSOs, all necessary information and data relating to
significant grid users in the distribution network. The necessary information shall be clearly
and transparently defined and agreed with the DSOs.