The Grid Code

The Grid Code is the technical document which establishes the rules governing the operation, maintenance and development of the transmission system and sets out the procedures for governing the actions of all transmission system users. The document ensures that all users are treated in a transparent and equitable manner. For the purposes of the Grid Code, a user is defined as any party using or planning to use the transmission system. 

EirGrid is responsible for the development and maintenance of the Grid Codes in Ireland, through the Grid Code Review Panel (GCRP). The GCRP is a standing body mandated to review and discuss the Grid Code, its workings and offer suggestions for amendments. Each member of the GCRP represents the interests of the constituents of their appointing body and has the responsibility of engaging with their constituents and discussing their views. Any subsequent modifications, updates and derogation requests must be approved by the relevant Regulatory Authority. It is important to note that the Grid Code is not intended to describe aspects of market operation or the rules for trading and settlement, as these are contained in the Trading and Settlement Code.

The Grid Code is continuously evolving to ensure compatibility with the I-SEM (wholesale electricity market), new generation technologies, demand side management and Network Codes

The most up to date version of the Grid Code can be found here.

To view a list of Grid Code modifications, click here.

Grid Code Review Panel Meeting Documents and Modification Proposals can be found here.

Any person may register to be a constituent where that person holds an electricity generation licence or an electricity supply licence. Please contact the secretary of the GCRP at if you are eligible to register.

Additional Grid Code documents can be found in the Grid Code section of the Library.

To propose a Grid Code modification, please complete this form and submit to


The Application of the European Connection Network Codes to Existing Users of the Grid Code

On 14 April 2016, Commission Regulation (EU) 2016/631 establishing a network code on requirements for grid connection of generators (hereafter referred to as ‘RfG’) entered in force. Regulation (EU) 2016/631. The incorporation of the RfG parameters into the Ireland Grid Code was approved by the CRU on 14.06.2019 – for more information see MPID 275.

On 7 September 2016, the Commission Regulation (EU) 2016/1388 establishing a network code on requirements for demand connection (hereafter referred to as ‘DCC’) entered in force. Regulation (EU) 2016/1388. The incorporation of the DCC parameters into the Ireland Grid Code was approved by the CRU on 06.10.2020 – for more information see MPID 276(a)

On 15 September 2016, Commission Regulation (EU) 2016/1447 establishing a network code on requirements for grid connection of high voltage direct current systems and direct current-connected power park modules (hereafter referred to as ‘HVDC’) entered in force. Regulation (EU) 2016/1447.

A guideline has been produced by EirGrid and by ESB Networks detailing the criteria which will be used by EirGrid and ESB Networks in relation to modernisation, refurbishment or equipment replacement for existing users which would require a user to comply in part or fully with the requirements of RfG, DCC and HVDC. Please view the guideline document here.


Section GC9.1 of the Grid Code states that if a user finds that it is, or will be, unable to comply with any provision of the Grid Code, then it shall without delay report such non compliance to the TSO and shall, subject to the provisions if GC9.2 make such reasonable efforts as are required to remedy such non compliance as soon as reasonably practicable.

Please submit the applicable form from the list to

Performance Monitoring

The performance monitoring process is applied to Windfarm Power Station (WFPS) in terms of the categorisation of controllability assigned following the regulatory decision SEM-062-11 for priority Dispatch.

Read WFPS Performance Monitoring Controllability of Windfarms document.

This table shows Generator Trips greater than 100 MW. If you have any questions in relation to this data please contact