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.

In the future, the Grid Code will continue to evolve to ensure compatibility with the I-SEM (new wholesale electricity market), New Generation Technologies, Demand Side Management and Network Codes. 

Find version 6 of the Grid Code here.

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

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

View the names and contact details of the members of the Ireland GCRP by clicking here.

View the Register of Constituents for the Ireland GCRP 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 and do not feature in the current register.

Grid Code Review Panel Meeting Agendas and Modification Proposals can be found in Box.


01.11.16 EirGrid have published a consultation paper on the Proposed Grid Code modifications for I-SEM. This public consultation details the proposed Grid Code modification (redlined version and clean version) that is required to facilitate the operation of the transmission system when the proposed I-SEM arrangements become effective.

The requirement for the Grid Code modification is driven by decisions made by the SEM Committee. We are not consulting on the I-SEM principles embedded within this proposed Grid Code modification. These decisions have already made by the SEM Committee.

This consultation is open for the month of November 2016. We welcome your feedback on the questions raised in this paper. Responses should be sent to by 30 November 2016. We will review your feedback when the consultation period closes. We plan to present our final draft modification to the first grid code review panel meeting in 2017.

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