Consultation Notice - NI TSSPS

21 April 2023

Under Condition 20 of its Licence to Participate in the Transmission of Electricity (the Licence), SONI is required to periodically review the Northern Ireland Transmission System Security and Planning Standards (TSSPS).

SONI is presently carrying out a full review of the Northern Ireland TSSPS.  Any proposed changes will be consulted upon later this year following the conclusion of the review. 

During the course of the review, it has become apparent there is an urgency to update the criteria regarding the step change voltage limits. In accordance with Condition 20 of the Licence, SONI is holding a consultation now regarding specific changes to the voltage step criteria only.

The TSSPS Review Consultation Paper can be found here.

The current TSSPS are available on the SONI website at

Responses to this consultation should be submitted by email to The closing date for this consultation is 17:00 on Friday 19 May 2023.

Following the conclusion of the consultation period, SONI will prepare a report summarising any feedback received, an updated TSSPS and submit both to the Utility Regulator for its consideration.