SQSS Modifications

You can raise a modification – or mod – when you want to propose a change to any part of the SQSS. 

For more information or for help raising an SQSS modification, please contact [email protected].

Search for any current or concluded modifications by name or ID. You can sort mods by ID, name, status or date of update. Or filter according to status.

ID Sort ascending NameAffectedStatusLast updated
GSR027GSR027: Review of the NETS SQSS Criteria for Frequency Control that drive reserve, response and inertia holding on the GB electricity system Current 17 Jun 2021
GSR026GSR026: Adding Non- Standard Voltages to the SQSS Current 10 Dec 2020
GSR025GSR025: Updating the SQSS to reflect the recent modification to Engineering Recommendation P28 Current 10 Dec 2020
GSR024GSR024: National Grid Legal Separation Changes Concluded 13 May 2020
GSR023GSR023: Clarification of the N-1-1 Requirements and minor housekeeping change Concluded 26 Feb 2020
GSR022GSR022: Review of Security and Economy Required Transfer Conditions Current 13 May 2020
GSR021GSR021: Operational and Planning Criteria for 220kV Transmission Assets Concluded 26 Feb 2020
GSR020GSR020: Modification of Clause to Allow Single Transformer Offshore Substations of Capacity Greater Than 90MW Concluded 26 Feb 2020
GSR019GSR019: Review of Chapter 7 Double Busbar Requirements Concluded 26 Feb 2020
GSR018GSR018: Treatment of Sub-Synchronous Oscillations SSO in the NETS SQSS Concluded 26 Feb 2020