Transmission Policies and Standards

EirGrid plans, manages, develops and operates the national electricity transmission grid. As part of this, we manage Transmission Investment Policies. These set out the acceptable standards and regulations for transmission developments.

We engage with stakeholders when developing or changing our technical standards and policies. This is specifically true when changes could significantly increase customer project costs or planning requirements.

See our engagement process in the document below.

Transmission Policy Documents

Part of our role is to set technical standards for proposed transmission system connections. These standards govern the design and construction of new transmission assets, including:

We also provide guidance for proposed developments close to existing transmission infrastructure.

Below is a non-exhaustive list of technical standard documents for demand and generation customers to consider.

Functional Specifications

Standard Layout Drawings

110 kV

220 kV

Standard Single Line Diagrams

General Functional Specifications

Export Cables Functional Specifications

Offshore Substation Functional Specifications

Onshore Compensation Compound Functional Specifications

EirGrid Offshore Standard Layout Drawings

EirGrid Offshore Standard Single Line Diagrams

The standard layout drawings here are concept designs of the most commonly acceptable solutions. They are provided for guidance only.

Detailed project specific documentation is provided to applicants who have executed a connection offer with EirGrid. For more on the connection offer process, see our section on becoming a customer.

Information provided to customers on this website contains general and technical information, which is subject to change from time to time without notice. 

EirGrid makes no warranties or representations of any kind with respect to the general and technical information provided or the content of any other document or website referred to on this website. 

EirGrid cannot determine any proposed connection methods until the formal connection application process is completed. Until an application is submitted and the relevant detailed studies and an executed connection agreement are complete, EirGrid will not be in a position to confirm specific technical details. 

Customers should not act or refrain from acting on the basis of any information provided without seeking appropriate professional advice.

Use of the information provided is solely at the user's own risk. EirGrid does not accept liability for any loss or damage arising from use or reliance on the information provided.