Connection Codes
Connection Codes
Ensuring system security and sound technical evolution

Network codes and guidelines are binding rules governing connection requirements to the electricity networks in an effective and transparent manner. They were established in 2009 by the EU Regulation on conditions for access to the network for cross-border exchanges in electricity and recast in 2019 by the Regulation on the internal market for electricity.
The codes are crucial for ensuring the safety of system operation and the efficiency of the European Union's power grid.
Connection Codes
Grid Connection Codes
Grid connection refers to all the subjects establishing and maintaining a physical connection between the transmission and/or distribution grids and the grid users.
Grid connection, or network connection, is one of the areas regulated by the specific network codes. These rules aim to develop a harmonised electricity grid connection regime, as well as efficient and secure operations. This is particularly important in view of the integration of an increasing share of sources of renewable energy in the system. European rules on grid connection also ensure a fair competition in the electricity market, and facilitate the electricity trade across the Union.
Three network codes on grid connection have been developed:
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The network code on requirements for grid connection of generators (RfG Regulation) establishes common standards that generators must respect to connect to the grid.
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The network code on demand connection (DCC Regulation) sets up harmonised requirements that demand facilities must respect to connect to the grid.
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The network code on requirements for grid connection of high voltage direct current systems (HVDC Regulation) covers the definition of harmonised standards for direct current (DC) connections.
Connection Codes
Amendment to the Grid Connection Codes
The European Commission invited ACER to initiate the process to amend two existing EU grid connection network codes: the Network Code on Requirements for Grid Connection of Generators and the Network Code on Demand Connection.
ACER is running a public consultation from 17 July to 25 September 2023 to gather stakeholders’ views on concrete amendment proposals on two European electricity grid connection network codes. Stakeholders are able to submit their comments separately, to one or both network codes.
Additionally, ACER is organising a webinar on 19 July in order to:
- present ACER’s proposed amendments to the grid connection network codes;
- explain the purpose, process and timeline for the amendments, and the public consultation process; and
- address questions
Following the closing of the public consultation and the assessment of the stakeholders’ input, ACER plans to submit to the European Commission its proposed amendments to the grid connection network codes by the end of 2023.
The aim is to update the network codes to further support the EU power grid embracing emerging developments such as e-mobility, storage and energy communities.
Previous steps in the amendment process
ACER published a draft Policy Paper in May 2022 and gathered initial feedback from stakeholders during a public workshop and a public consultation in June 2022 (access the responses of the June 2022 public consultation in the Evaluation of Responses Report). Following this, ACER ran a full-fledged public consultation from 26 September until 21 November 2022, inviting interested parties to submit their concrete amendment proposals.
Policy Paper on the amendments to the grid connection network codes
In its Policy Paper published in September 2022, ACER provided a high-level outline of the main areas to improve the Network Code on Requirements for Grid Connection of Generators and the Network Code on Demand Connection.
The ACER Policy Paper on Grid Connection Network Codes reflects ACER’s considerations on possible amendments to the grid connection network codes following input received from stakeholders during the summer 2022.
The Policy Paper addresses potential amendments to the European network codes concerning among others:
- technical requirements for storage, mobile storage (e.g., electric vehicles) and electrical charging points;
- requirements for mixed customer sites (MCSs), active customers and energy communities;
- significant modernisation of system users’ facilities and equipment;
- advanced capabilities for grids with significant distributed energy resources (DER) and converter-based technologies; and
- criteria to determine generators significant for the system.
2022 Public Consultation
ACER evaluated the provided responses submitted by stakeholders in the course of the full-fledged 2022 public consultation (accessible under the Consultation documents section).
During the course of the revisions and assessment of stakeholders’ input, ACER organised three public workshops related to the amendment process of the network codes. The workshops focused on specific regulatory issues, namely:
- electromobility, power-to-gas demand units and heat-pumps (workshop on 17 April 2023);
- rate of change of frequency and grid forming capabilities (workshop on 10 May 2023); and
- electricity storage (workshop on 11 May 2023).
ACER plans to submit to the European Commission its proposed amendments to the grid connection network codes by the end of 2023.
Access the 2023 Public Consultation.
Access the Webinar on amendments of European electricity grid connection network codes (GC NCs).
Access the 2022 Public Consultation and stakeholders’ responses.
Access the Public Workshop and the presentations.
Access the ACER’s workshops on electromobility, power-to-gas demand units and heat-pumps, on rate of change of frequency and grid forming capabilities, and on electricity storage.