CMP276 proposes replacing TNUoS demand residual Triad charge with two new socialised demand charges

On 6 February 2017 Alkane Energy Ltd raised CUSC Modification Proposal CMP276, requesting urgent treatment, to replace the TNUoS demand residual ('Triad') charge with two new charge lines applied to all demand offtakes: (i) a fixed charge per MPAN (or alternatively based on import meter size) and (ii) a simple per-kWh charge on all consumers. At its Special meeting on 10 February 2017 the CUSC Modifications Panel unanimously decided CMP276 did not meet Ofgem's urgency criteria, judging its scope broader and more complex than envisaged, with implications requiring full Workgroup deliberation. The Panel recommended the standard (non-urgent) Workgroup timetable to Ofgem rather than the urgent timetable also considered.

The demand residual is the TO cost 'bucket' that captures otherwise unallocated transmission costs and is forecast to drive high TNUoS Triad payments for demand customers unless the charging methodology changes. CMP276 is positioned as a broader, non-discriminatory alternative to narrower parallel proposals (CMP264/CMP265), aiming to reduce distortive Triad-avoidance behaviour, improve equity across domestic and international markets, and create an enduring charging structure. The urgency rejection and Workgroup referral materially extend the timeline and subject the proposal to deeper multi-stakeholder scrutiny before any change to GB transmission charging reaches demand customers.

This is a transmission charging (TNUoS) methodology reform process under the CUSC code, distinct from wholesale, balancing or capacity market design, but with first-order effects on demand-side cost allocation and behavioural incentives (notably Triad avoidance). By proposing to convert a residual, hard-to-forecast demand charge into two more predictable components (a fixed per-MPAN/meter-size charge and a flat per-kWh charge), CMP276 would reduce the incentive for demand customers to curtail load narrowly around Triad periods, which has knock-on effects for system balancing, embedded generation economics, and flexibility/demand-response business models that currently monetise Triad avoidance. The Panel's rejection of urgency and the decision to route the proposal through a full Workgroup (with the standard, not urgent, timetable) signals that the scope is being treated as strategically significant and overlapping with, but broader than, CMP264/CMP265 and CMP271. The recommended standard timetable sets out a multi-stage process (Workgroup consultation, Code Administrator consultation, draft and final Modification Reports) culminating in an indicative Authority decision and implementation date in December 2017, though these are explicitly framed as indicative pending Ofgem's urgency ruling and subsequent Workgroup findings. For market design tracking, this event establishes the baseline proposal and procedural timetable; subsequent milestones (Ofgem's urgency decision, Workgroup Alternative CUSC Modifications, and the Authority's final decision) will determine whether GB demand residual charging shifts from a capacity/Triad-based signal toward flatter, more predictable cost recovery mechanisms.

CUSC (Connection and Use of System Code) Modification Proposal process under the GB electricity transmission licence, subject to Ofgem (the Authority) decision

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