Connections Process - Northern Ireland

1. Customer contacts SONI

Customer contacts SONI ( to discuss project and connection options.

2. Connection Application

After obtaining planning permission the Customer will submit a completed connection application form to SONI. Please contact for application forms. SONI will then have three months to offer the customer terms for connection to the Transmission System.

3. Connection Offer

Studies shall be carried out to ensure that any new network additions or modifications do not result in unacceptable or unstable conditions on the Transmission System. This will be done by undertaking a number of system studies replicating the Customer’s proposed development and the effect it may have on the All-Island Transmission Networks.

The cost (which are included in the Connection Offer) of such studies shall be charged to the prospective Customer, who shall be liable to meet the costs in full whether or not the Customer proceeds with any or all of the project(s) under investigation. Under License Condition 30, SONI has prepared a statement setting out the basis upon which charges will be made for connection to the All-Island Transmission Networks (available here).

4. Bilateral Agreements

Connection Agreement. A SONI Connection Agreement will specify the capacity and characteristics of the equipment which may be connected to the Transmission System. The Agreement will show the configuration of the Customer’s equipment and NIE equipment and will identify the point(s) of connection. The entry into a Connection Agreement is part of the requirements on a Customer of accepting a Connection Offer from SONI.

Transmission Use of System Agreement (TUoSA). Under the terms of the Trading and Settlement Code, a TUoSA is required by all Generators in order to participate in the Single Electricity Market (SEM). If a Generator is greater than 5MW it is required to pay TUoS. A Generator with a capacity greater than 10MW will be obliged to participate in the SEM. For further information consult the SEM-11-078 paper. The TUoSA will be between the customer and SONI and among other things it places obligations on the WFPS to comply with the entire Grid Code.

The TUoSA will need to be in place between SONI and the customer prior to energisation. It may take up to 28 days to get the TUoSA in place once all of the necessary information has been provided to SONI, so please ensure that this has been taken into consideration. The application form for the TUoSA is available here and further information on TUoS charges is available here.

Grid Code Compliance Agreement (GCCA). Generators with a Registered Capacity between 5-10MW will be required to enter into a GCCA if the Generator is not a SEM participant. The GCCA places obligations on the Generator to comply with the Grid Code Connection Conditions.

5. Energisation

Energisation cannot take place prior to all relevant agreements are signed. Once all pre-energisation criteria have been met then an energisation notice will be issued.

6. Compliance Testing and Certification

The Commissioning/Acceptance Test Panel will co-ordinate and agree the Compliance testing program, provide direction on technical requirements, assess the test results and deicide if Compliance has been achieved. A Final Compliance Certificate will be issued upon satisfactory completion of tests and performance monitoring.

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