Becoming a customer

Any user seeking a connection to the Northern Ireland transmission system (connecting at ≥ 110kV) must enter into a connection agreement with SONI. This includes modifications to a connection.

A connection agreement specifies the capacity and characteristics of the equipment which may be connected to the transmission system.

Under the terms of our licence (Condition 25), SONI shall offer terms for connection to the all-island transmission networks. We've published a policy explaining the process for making an application to connect to the transmission system.

 For distribution system connections (≤ 33kV), please visit NIE Networks.

Step 1: Pre-application

You should first contact us by email: connections@soni.ltd.uk

We will provide you with a 'customer pre-meeting form' to submit before meeting with you. This form contains links to various helpful documentation. Once received, we will arrange a virtual meeting to discuss your project and the connection options.

Once you are in a position to apply, you may email your completed Connection Application Form to connections@soni.ltd.uk. 

Applicants must meet the following prerequisites to deem the application effective:

It is not required to have the relevant consent for a project at application stage. However, the process of obtaining it should be at an advanced stage when submitting a connection application. A relevant reference number is required within the Connection Application Form. For example, the planning reference from the Northern Ireland planning portal.

Applicants will have a minimum of 180 days from the application effective date to secure relevant consent. This is typically comprised of the 90 day offer process time and 90 day offer acceptance period. See the Connections Policy below for more info.

PDF versions of the application forms are available below. Please contact connections@soni.ltd.uk if you need a word version.

We endeavour to issue connection offers within 90 days of the application date. Where a connection is complex this may not be possible. We may need to request an extension to the offer timelines from the Utility Regulator. When this is the case, the timescale for the offer will be adjusted accordingly.

The Connections Policy below details the connection offer process.

Studies are carried out to ensure that new network additions or modifications do not result in unacceptable or unstable conditions on the transmission system, as set out in the Transmission System Security and Planning Standards (TSSPS). System studies replicate the customer’s proposed project and the effect it may have on the transmission network

The cost of such studies is charged to the prospective customer. The customer shall be liable to meet the costs in full, whether or not they proceed with any or all of the project(s) under investigation. The cost is included in the connection offer.

Under License Condition 30, we have prepared a Transmission Connection Charging Methodology Statement. It sets out the basis for charges to connect to the all-island transmission network.

Connection agreement

Connections (or a modification to a connection) require a connection agreement with SONI. A connection agreement specifies the capacity and characteristics of the equipment which may be connected to the transmission system.

 It includes details on the:

The connecting party and SONI must sign the connection agreement before energisation.

Transmission Use of System Agreement (TUoSA)

Under the terms of our licence (Condition 25), SONI shall offer terms for the use of the all-island transmission networks (TUoS). Under condition 16 of the Licence, we are required 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 the terms of the Trading and Settlement Code, a TUoSA is required by all generators to participate in the Single Electricity Market (SEM). The TUoSA is between the customer and SONI. Among other things, it places obligations on the customer to comply with the entire Grid Code. 

The TUoSA needs 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. Please ensure that this has been taken into consideration. See TUoS Application Form and Statement of Charges below. 

Suppliers and generators of greater than 5 MW capacity

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. 

Grid Code Compliance Agreement (GCCA)

Generators with a registered capacity between 5-10 MW 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.

Energisation cannot take place before all relevant agreements are signed and pre-energisation criteria are met. Once all pre-energisation criteria have been met, an energisation notice will be issued.

Compliance testing keeps the grid safe and stable. The Commissioning/Acceptance Test Panel will:

A Final Compliance Certificate is issued on satisfactory completion of tests and performance monitoring.

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.

See more information on contestability, the process and relevant documentation below.