Security and Quality of Supply Standard (SQSS)

Transmission licensees – both onshore and offshore – are required by their licences to comply with the National Electricity Transmission System Security and Quality of Supply Standards (NETS SQSS), which sets out criteria and methodologies for planning and operating the GB Transmission System.

The SQSS Panel is responsible for keeping the standard under review and submitting any proposed changes to us for a decision.

In certain circumstances Ofgem may grant a derogation from the obligation to comply aspects of the NETS SQSS. Under the Connect and Manage process (which allows generation to connect before wider works to the transmission system have been completed) National Grid Electricity Transmission (as System Operator) also has the power to grant certain derogations.

Publications and updates

  • Published: 16th Feb 2018
  • Closed: 19th Mar 2018
  • Change proposal, Consultations and responses
  • 1 Associated documents
Changes to the standard licence conditions to reflect the latest version number of the NETS SQSS (V2.4)

  • Published: 12th Dec 2016
  • Decisions
  • 1 Associated documents
Standard licence conditions to be changed to reflect the latest version number of the NETS SQSS (V2.3).

  • Published: 12th Oct 2016
  • Closed: 16th Nov 2016
  • Consultations and responses
  • 2 Associated documents
Changes to the standard licence conditions to reflect the latest version number of the NETS SQSS (V2.3).

  • Published: 4th Jul 2016
  • Decisions
  • 1 Associated documents
GSR0021 proposed changes to accommodate 220kV voltages. We have not approved this modification to Chapter 6 of the SQSS.

  • Published: 4th Jul 2016
  • Decisions
  • 1 Associated documents
We have approved the modification (GSR0011) to the SQSS that implements changes to Chapter 7 (Offshore Transmission network) and Chapter 11 (Terms and Definitions).

  • Published: 4th Jul 2016
  • Decisions
  • 1 Associated documents
GSR008-1 implements changes to the onshore transmission network chapters of the SQSS, which introduce clarifications and remove regional variations. We have approved this modification to the SQSS.

  • Published: 3rd Dec 2014
  • Decisions
  • 1 Associated documents
We have approved this modification to the SQSS. GSR015 removes ambiguity in the definitions of the SQSS to ensure National Grid only procures efficient levels of a balancing service known as frequency response.

  • Published: 10th May 2012
  • Closed: 8th Jun 2012
  • Consultations and responses
  • 5 Associated documents
This letter sets out the process we intend to follow in considering the proposed changes to the SQSS.

  • Published: 14th Nov 2011
  • Decisions
  • 1 Associated documents
This letter sets out our decision on GSR002-1, a proposal to make a number of housekeeping amendments to the National Electricity Transmission System Security and Quality of Supply Standard (NETS SQSS).

  • Published: 1st Nov 2011
  • Decisions
  • 1 Associated documents
This letter sets out our decision on GSR009, a proposal to modify the way in which the minimum transmission capacity requirements are determined in National Electricity Transmission System Security and Quality of Supply Standard (NETS SQSS).

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