SONI (Electricity System Operator for Northern Ireland) and NIE Networks Transmission Interface Arrangement Consultation – Publication of Final Amendment Reports

30 September 2020

SONI, the Electricity Transmission System Operator for Northern Ireland, and Northern Ireland Electricity Networks (NIE Networks), the Transmission System Owner, work in partnership to serve Northern Ireland consumers, by providing a safe, reliable and efficient electricity supply.


We operate through the Transmission Interface Arrangements (TIA) which has been in place since 2007. The TIA is designed to promote co-operation and co-ordination between SONI and NIE Networks in planning and developing the transmission system.


Working together, both companies have carried out a joint review of the Transmission Interface Arrangements, with emphasis on the pre-construction elements of grid development projects.


The findings concluded that the processes in place are operating proficiently, with some improvements proposed to enhance efficiencies and further benefit the Northern Ireland consumer.


The proposed amendments will not change any decision-making rights or TIA principles but will provide more clarity for both organisations.


In July 2020, a joint SONI – NIE Networks consultation was held on the proposed amendments to the TIA. Today, we are publishing the final amendment reports which summarise and respond to the comments received.

The SONI Amendment Report - (as agreed with NIE Networks) contains proposed amendments to TIA Sections B and U.

The NIE Networks Amendment Report – (as agreed with SONI) contains proposed amendments to TIA Sections C, D and U.


We would like to thank all parties for their responses.


These reports will now be will be submitted to the Utility Regulator for Northern Ireland in accordance with the TIA.