How to Get Connected

SONI is Northern Ireland's independent Transmission System Operator. Customers should note that SONI does not buy or sell electricity, but facilitates the connection of generation and large scale demand customers to the Transmission System.

Under the terms of our License (Condition 25), SONI shall:

  • Offer terms for the use of the All-Island Transmission Networks (TUoS) and
  • Offer terms for connection to the All-Island Transmission Networks

Transmission Use Of System (TUoS)

Suppliers and Generators seeking to use the Transmission System will be required to enter into a Transmission Use of System Agreement (TUoSA) with SONI. License Condition 16 places a requirement on SONI to implement and comply with the Grid Code. The TUoSA sets out the ‎‎obligations of both parties to comply with the relevant Grid Code requirements

Under License Condition 30, SONI have prepared a statement setting out the basis upon which Generators and Suppliers will be charged for use of the All-Island Transmission Networks. More information on use of system charges can be found on the TUoS Tariffs and Billings page.

Transmission Connections

Any user seeking a connection (or a modification to a connection) to the Northern Ireland Transmission System must enter into a Connection Agreement with SONI. A Connection Agreement will specify the capacity and characteristics of the equipment which may be connected to the Transmission System.

SONI has published a policy explaining the process for making an application to connect to the Transmission System, effective 1 February 2018 at 9:00am. The publication sets out the steps that the customer must follow to make a valid connection application, the offer requirements (particularly those related to planning permission for the proposed project), and details the steps for connection to the Northern Ireland Transmission System. An explanatory note is also provided for information. Additional information on the steps of the connections process can be found here.

Here is the SONI Connections Policy with an accompanying Explanatory Note.

It is recommended that prospective customers make contact with SONI at an early stage of the project. SONI will provide guidance on technical issues and plant performance requirements.

Please note, for information relating to connections to the Distribution System, you can visit the NIE Networks website.

Application Forms

Contestability in Connections

Contestability is the process where an Independent Connection Provider (ICP) may undertake elements of the provision of a new connection to either the transmission or distribution system.

For distribution related enquiries please contact NIE Networks.

More information on contestability, the process and relevant documentation can be found here.

Generator Connections - FAQ Analysis

For details on FAQ allocation, please see the 2013 Connections Process Decision Paper available here.

Further Information

For Connections related queries please contact: