NESOOFGEMDESNZ
Connection and Use of System Code
CMP440Workgroup

CMP440: Re-introduction of Demand TNUoS locational signals by removal of the zero-price floor

NESO (CUSC)·regulation·high·14 Aug 2024·source document

What is being proposed

This CUSC modification Proposal would remove the current zero price floor from the Transmission Network Use of System (TNUoS) locational demand tariff for Final Demand, thereby re-introducing a locational investment price signal across all of Great Britian(GB). The potential for negative prices and the perverse incentive for users to consume is removed by widening the period over which consumption is measured for charging against negative tariffs.

Current status

The Proposal was presented to the September 2024 CUSC Panel, where the Panel unanimously agreed that CMP440 should follow the Standard route and proceed to a Workgroup. The Panel agreed the Terms of Reference for the Workgroup. Workgroup Nominations were published to industry on 04 October until 01 November 2024.The October 2024 CUSC Panel prioritised the modification as High. Timeline was presented to the November 2024 CUSC Panel - Panel agreed to the proposed timeline. First Workgroup was planned for 08 January 2024. Upon receipt of the Authority Open Letter on 31 January: Outlining their approach to prioritisation of electricity transmission network charging modifications, Panel reviwed the modification status in the February Panel. Workgroup meetings in progress. (09.02.2026) The CUSC Panel agreed on 30 January 2026 that this modification may proceed to the Code Administration Consultation this will commence on 09 February to 03 March.

Details

Proposed byRWE
Decision byOfgem
GovernanceStandard Governance (Workgroup)
Impact onHigh impact: Suppliers
Also affectsSQSS

Timeline

Proposal raised14 Aug 2024
Workgroup report to panel19 Jun 2025
Code Administrator Consultation opens9 Feb 2026
Code Administrator Consultation closes3 Mar 2026
Panel vote27 Mar 2026
Sent to Ofgem9 Apr 2026
Ofgem decision30 Sept 2026
Implementation1 Apr 2027

Analysis

CUSC modification CMP440 removes the zero price floor from demand TNUoS locational tariffs, reintroducing negative prices as investment signals. Negative tariffs apply over extended consumption measurement periods to prevent gaming. Code Administration Consultation runs 9 February to 3 March 2026.

Why it matters

This prices locational scarcity directly rather than administratively capping it at zero, creating proper investment signals for demand-side resources. Suppliers bear the cost risk of poor location choices, as such the reform shifts grid cost allocation from socialised to causal.

Key facts

  • Removes zero price floor from TNUoS demand tariffs
  • Extended consumption measurement periods prevent gaming of negative tariffs
  • Code Administration Consultation: 9 February - 3 March 2026
  • High priority modification under Standard Governance route

Areas affected

network chargestransmissionsupplierswholesale market

Related programmes

TNUoSConnections Reform