GC0117: Improving transparency and consistency of access arrangements across GB by the creation of a pan-GB commonality of Power Station requirements
What is being proposed
This modification will set out within the Grid Code the common GB obligations in the EU Connection Codes as they relate to the specification of certain items by certain obligated party or parties.
Current status
The Panel met in June 2018 and agreed that it goes to a Workgroup. Workgroup meetings commenced on 18 October 2018. Workgroups were paused until May 2021 due to Panel prioritisation. Workgroup meetings restarted on 19 May 2021. In March 2022, the Workgroup received Panel approved to extend their timeline to allow a further two Workgroup meetings to refine legal text for WAGCMs. Following feedback from the Workgroup Consultation a CBA will be conducted, an amended timeline was agreed at the August Grid Code Review Panel. Further to this the October Grid Code Review Panel agreed the new timeline, allowing for the CBA to be completed by February 2023. A CBA Check in meeting was held on 8 December 2022. An updated timeline was approved by the March 2023 Grid Code Review Panel. An updated timeline was approved by the June Grid Code Review Panel for approval. Due to additional analysis required for WAGCM1 the Workgroup Report which was intended to the issued to the August 2023 Grid Code Review Panel was delayed, an updated timeline was submitted in both the July 2023 and August 2023 Grid Code Review Panels. July 2023 GCRP approved the retrospective title change to include the reference to ‘Power Station requirements’ and the new timeline as submitted within the Panel Papers. A new timeline was presented to the August 2023 Grid Code Review Panel which the panel approved. A new timeline was presented to the October 2023 Grid Code Review Panel which the panel approved. A new timeline was presented at the December 2023 Grid Code Review Panel meeting. The Panel approved the timeline. The Workgroup Report was presented at the January 2024 Grid Code Review Panel meeting. The Panel agreed that the Terms of Reference have been met and agreed for GC0117 to proceed to Code Administrator Consultation, subject to a legal text concern raised by a Panel member being addressed and confirmation from the Authority regarding a potential interaction with CMP298 (these two matters to be approved by Panel via e-mail ahead of the Code Administrator Consultation). The Code Administrator Consultation ran from 19 February 2024 and until 26 March 2024 and received 13 non-confidential responses (0 confidential). The Draft Final Modification Report was issued to the April 2024 Grid Code Review Panel for the Panel to complete their recommendation vote. The Panel held their recommendation vote, with 4 Panel members noting that the Original better facilitates the Grid Code objectives than the Baseline and 2 Panel members noting that WAGCM1 better facilitates the Grid Code objectives. The Panel were unable to reach a consensus on whether the Original Proposal better facilitated the Grid Code objectives than the Baseline. The Final Modification Report was issued to the Authority on 14 May 2024. The Authority will be running a Consultation on their draft decision letter, ahead of issuing their final decision, which is expected to be issued on 06 December 2024. Ofgem EDD for October 2024 confirms expected decision date of 06 December 2024. 06/11/2024 The authority decision will be dependent on whether a 4 or 6 week consultation period period was required and if the latter then the decision date would be in the New Year, rather than 06 December 2024. An Impact Assessment Consultation will be issued on 06/01/2025 and open for 6 weeks, with the expected decsion date to be in the New Year. The Authority sent back this modification on 18 July 2025. At the meeting on 21 August, the Panel agreed Terms of Reference and asked for the Workgroup to be re-formed. Further Workgroup nominations opened on 28 August and closed on 18 September. The Workgroup are considering feedback from the DNO's on the CBA. 09/03/2026 The next Workgroup is shceduled for 19 March, new timeline TBC.
Details
Timeline
Analysis
GC0117 seeks to harmonise GB power station connection requirements by implementing EU Connection Code obligations within the Grid Code. The modification has been under development since 2018, was sent back by Ofgem in July 2025, and workgroups are now reconsidering DNO feedback on the cost-benefit analysis. The next workgroup meeting is scheduled for March 19, 2026.
Why it matters
This represents administrative harmonisation rather than fundamental reform — standardising existing obligations across GB transmission networks without changing underlying connection economics or queue management. The six-year development timeline and regulatory rejection suggest complexity that may not justify the coordination benefits.
Key facts
- •Modification under development since 2018
- •Sent back by Ofgem in July 2025
- •Affects multiple network codes: CUSC, STC, BSC
- •Next workgroup meeting March 19, 2026