P502 Timetable Firms Up: Elexon Specifies January 2027 Assessment Procedure Consultation Window

Elexon's updated P502 modification page confirms the existing end-to-end timetable (Assessment Report to Panel 13 May 2027; Report Phase Consultation 17 May–18 June 2027; Draft Modification Report 8 July 2027; Final Modification Report to Authority 19 July 2027) and newly specifies a tentative Assessment Procedure Consultation window of 7–27 January 2027 (marked TBC), filling in a date that was previously unscheduled. The Workgroup assessment period is reconfirmed as running January–December 2026, consistent with the three meetings already held (30 Jan, 26 Mar, 21 May 2026) and the fourth meeting still scheduled for 5 November 2026, one day after this source's publication date.

The newly disclosed (if still tentative) consultation window gives BSC Parties and Independent Aggregators a concrete near-term date to prepare responses on the proposed two-way ABSVD compensation mechanism, allowing Suppliers and aggregators to plan resourcing for stakeholder input ahead of the Assessment Report. Confirmation of the downstream 2027 milestones without slippage signals the Workgroup is tracking its original schedule, reducing uncertainty for parties assessing when settlement-neutral treatment of aggregator-driven ABSVD adjustments might take effect.

This update is primarily a scheduling refinement rather than a substantive design development: no new detail is given on the compensation methodology itself, the treatment of gaming risk between Suppliers and Independent Aggregators, or interaction with related workstreams (P518, P412). The fact that the full 2027 report-phase timetable remains unchanged suggests Elexon/NESO have not yet encountered scope or complexity issues requiring a timetable extension, which is notable given the topic's technical difficulty. The still-tentative (TBC) status of the January 2027 consultation window indicates the Workgroup has not yet finalized its assessment conclusions, and the substantive design choices—particularly how compensation values will be calculated and whether they introduce new gaming vectors—likely remain open pending further Workgroup sessions through the rest of 2026.

Balancing and Settlement Code (BSC)

Fourth Workgroup meeting · 5 Nov 2026

Primary sources