CMP442: Introducing the option to fix Generator TNUoS charges
What is being proposed
This modification gives Generators the opportunity to fix their wider Transmission Network Use of System (TNUoS) charges against the forecasted tariffs provided by NESO.
Current status
Propsal was raised for the October CUSC 2024 Panel. The Panel unanimously agreed that CMP442 should follow the Standard Governance route and proceed to a Workgroup. The Panel did not approve the Terms of Reference for the Workgroup. As the October 2024 CUSC Panel prioritised as High. Timeline presented to the November 2024 CUSC Panel - Panel agreed to the proposed timeline. First Workgroup planned for 16 December 2024. Upon receipt of the Authority Open Letter on 31 January: Outlining their approach to prioritisation of electricity transmission network charging modifications, Panel reviewed the modification status in the February CUSC 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 this modification be placed as medium on the prioritsation stack. 10/11/2025
Details
Timeline
Analysis
CMP442 allows generators to fix their TNUoS charges against NESO's forecasted tariffs, converting variable transmission charges into predictable costs. The modification follows standard governance through workgroup process, with first workgroup meeting planned for 16 December 2024. CUSC Panel initially prioritised this as high but downgraded to medium priority in February 2025 following Ofgem's transmission charging modification prioritisation guidance.
Why it matters
This creates a hedge against TNUoS volatility for generators, reducing their revenue uncertainty but potentially transferring forecasting risk to consumers who ultimately bear transmission costs. The modification addresses the economic problem of unpredictable charges distorting investment decisions, though the mechanism for how fixed charges interact with actual costs remains undefined.
Key facts
- •Allows generators to fix TNUoS charges against NESO forecasts
- •First workgroup meeting: 16 December 2024
- •Priority downgraded from high to medium in February 2025
- •High impact on generators, NESO, and suppliers