CMP405: TNUoS Locational Demand Signals for Storage
What is being proposed
Seeks to separate out the demand Year Round locational signals from Peak Security locational Signals and charge (reward) Storage which imports during times other than Triads
Current status
The Panel met on 25 November 2022 and agreed that it goes to a Workgroup (in parallel with CMP393). 1st Workgroup was held 13 January 2023. A new timeline was approved by the August 2023 CUSC Panel. The November 2023 CUSC Panel approved the submitted change to the Terms of Reference. The December 2023 CUSC Panel approved the submitted updated timeline. A timeline update was approved by the April 2024 CUSC Panel. The October 2024 CUSC Panel prioritised as Low, therefore no work will take place on this modification until further notice. On 17 December 2024 the Proposer requested the status for this modification be changed to urgent. A Special SQSS Panel was held on the 10 January to dicuss. The Panel by majority agreed that CMP405 met the Authority’s Urgency criteria (a), and therefore recommended urgent treatment. Panel’s recommendation was sent on 10 January 2025 seeking an Authority decision. On the 20 January 2025 the Authority rejected the requested change of governance route from Standard to Urgent. Upon receipt of the Authority Open Letter on 31 January: Outlining their approach to prioritisation of electricity transmission network charging modifications, Panel will review the modification status in the February Panel. On 14 February 2025 at the Special CUSC Panel the Panel discussed, at length and in detail, the prioritisation of CUSC Modifications. The CUSC Panel agreed there is no change to this priority status. On 28 March 2025 the CUSC Panel discussed at length and in detail the prioritisation of CUSC Modifications. The CUSC Panel agreed this modification be placed as low on the prioritsation stack. (08/09/2025) In the postponed 03 September Panel, the Panel agreed to keep this modification as low priority.
Details
Timeline
Analysis
CMP405 proposes to separate TNUoS demand charges into year-round locational signals and peak security signals, charging storage that imports outside Triad periods while rewarding it during other times. The modification has been deprioritised as low priority by CUSC Panel despite proposer requests for urgency, with Ofgem rejecting urgent treatment in January 2025. Panel confirmed low priority status in March and September 2025, effectively stalling progress.
Why it matters
Storage operators face continued uncertainty as current charging arrangements penalise them for providing grid services outside peak periods, while the delay preserves incumbent generators' advantage in TNUoS cost allocation. The stalled modification demonstrates how governance processes can block pricing reforms that would better reflect storage's grid value.
Key facts
- •Modification running in parallel with CMP393
- •Authority rejected urgent treatment request on 20 January 2025
- •Panel confirmed low priority status September 2025
- •High impact on storage generators and transmission operators