Grid Code What is the Standard Modification Process? Panel (approve timeline and Terms of Reference) Workgroup Phase Workgroup Consultation (at Panel’s discretion) Alternatives to formally be raised at or before this point Workgroup Vote Code Admin Consultation (following Panel approval) Panel Vote Submission to Authority The standard Workgroup Phase timeline is 6 months but there is aan option to request an extension subject to Panel/Ofgem approval. This was an important discussion of the GC0086 Workgroup and the outcome of which was to agree a process and timeline.

Grid Code Standard Modification Key Points A Grid Code Modification Proposal that does not fall within the scope of a Significant Code Review subject to any direction by the Authority, nor meets the Self-Governance Criteria subject to any direction by the Authority. The Panel in conjunction with the Code Administrator will determine the timeline, number of Consultations required and agree terms of reference. At the Workgroup stage parties can raise an alternative modification proposal which has the support of the majority of Workgroup members or the Workgroup Chairperson as better meeting the Grid Code objectives. The Workgroup vote is an informal recommendation for the Panel and will be an element incorporated within the Report submitted to the Panel. If an alternative is suggested, it has to be better than the baseline or better than the proposed solution.

Progression of a Modification Modification Raised Timescales Urgent Modification Initial Written Assessment <1 Month Fast Track Self-Gov. Modification Straight to Report Assessment Procedure 3-4 Months Send Back Report Phase 1-2 Months Self-Gov. Modification With Authority 1-2 Months Decision BSC Change Processes

Assessment Procedure Consultation Used to develop the proposed solution and any alternative (either before or after the Assessment Procedure Consultation) All impacts are identified on: The BSC and CSDs BSC Systems (via Service Provider IAs) Other Industry Codes Participants (via industry consultations and/or IAs) Assessment Report will be produced with Workgroup’s final recommendations and presented to the Panel on behalf of the Workgroup When considering the Assessment Report, the Panel will: Provide its initial views on the Applicable BSC Objectives Make an initial recommendation on whether the Modification should be approved Impact Assessment Assessment Procedure Consultation Assessment Report Workgroup meeting(s) BSC Change Processes

Initial Written Assessment Report Phase Panel’s initial views are consulted on via the Report Phase consultation Panel will consider the responses and make its final recommendation to the Authority Final recommendations are captured in the Final Modification Report and issued for Authority determination Initial Written Assessment Assessment Procedure Report Phase With Authority Normally the final report is checked by Douglas and/or internal expert BSC Change Processes

Modification Procedure without system change BSC Modification Procedure Grid Code Modification Procedure Workgroup meeting(s) Draft Consultation – WG comment Draft WG Report – WG Comment Assessment Procedure Consultation Workgroup Consultation WG Consider Consultation responses Alternate Solutions may no longer be submitted or considered Submit report to Panel Report Phase Consultation Code Admin Consultation Submit Final Report to Panel Final Report submitted to Ofgem for approval by The Authority BSC Change Processes