Transmission Policies and Standards

Our guidance on policies and technical standards for connections to the grid.

Policies for Customer Connections

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.

Technical Standards and Policies Engagement Process (PDF, 232KB)

Transmission Policy Documents

Technical Standards for Customer Connections

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:

Transmission substations
Cables
Overhead lines

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

110/220/400 kV Station General Requirements (XDS-GFS-00-001-R4)
110kV/220kV/400 kV Underground Cable Specification (CDS-GFS-00-001-R1)
110kV Underground Cable Drawings
110/220/400 kV GIS Specification (XDS-GFS-25-001-R4) - Currently Under Review
Control, Protection and Metering Specification (XDS-GFS-06-001-R2)
Station Auxiliary Power Supplies Specification (XDS-GFS-08-001-R3)
Earthing and Lightning Protection (XDS-GFS-12-001-R4)
Earthing and Lightning Protection Drawings (XDS-DGA-00-004-R04)
Station 220 V, 48V and 24 V Lead Acid Batteries and Chargers (XDS-GFS-09-001-R4) - Currently Under Review
Substation Civil and Building Works (XDS-GFS-13-001-R2) - Currently Under Review

Standard Layout Drawings

110 kV

110 kV AIS Substation - 8 Bay (XDN-LAY-ELV-STND-H-001-R08)
110 kV AIS Single Transformer Tail Station (XDN-LAY-ELV-STND-H-003-R04)
110 kV AIS 2-Bay Station Extendable to 4-Bay & 8-Bay Configurations (XDN-LAY-ELV-STND-H-013-R02)
110 kV AIS Station Typical Control Room (XDN-CR-STND-H-001-R01)
110 kV GIS Station - 8 Bay (XDN-LAY-ELV-STND-H-005-

220 kV

220 kV GIS Substation - Single Bay (XDN-LAY-ELEV-STND-F-002-R00)
220 kV GIS Substation - 8 Bay (XDN-LAY-ELEV-STND-F-005-R00)
220 kV GIS Substation - 12 Bay (XDN-LAY-ELEV-STND-F-004-R01)

Standard Single Line Diagrams

Customer 110 kV AIS C-Type SLD (XDN-SLD-STND-H-005-R03)
Customer 110 kV GIS C-Type SLD (XDN-SLD-STND-H-006-R02)
110 kV AIS 2-Bay Station Extendable to 4-Bay & 8-Bay Configurations (XDN-SLD-STND-H-009-R02)

Offshore Technical Standards for Customer Connections

EirGrid Offshore Standard Layout Drawings

220kV GIS Onshore Compensation Compound Layout - Drawing 1 and Drawing 2 (OFD-SSS-503-R00)
220kV AIS Onshore Compensation Compound Layout (OFD-SSS-501-R00)

EirGrid Offshore Standard Single Line Diagrams

220kV AIS Onshore Compensation Compound Diagram (OFD-SSS-500-R00)
220kV GIS Onshore Compensation Compound Diagram (OFD-SSS-502-R00)

Connection Offer Process

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.

Disclaimer

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.