CMP456: Cost recovery for legacy plant in relation to GC0168
What is being proposed
Implementation of GC0168 brings the obligation, on request, for existing plant to procure and submit EMT plant models. This is a considerable task for older plant with multiple discreet systems. The cost of this is significant and the benefit is not to the generator involved..This modification is to enable suitable cost recovery for the provision of such models.
Current status
Proposal raised on 19 June. CMP456 is linked to GC0168 'Submission of Electro Magnetic Transient (EMT) Models' which was delayed going to Code Administrator Consultation. Progression on GC0168 will affect CMP456 moving forward. Proposer to confirm whether CMP456 should be progressed on an urgent basis and then presented to CUSC Panel. A critical friend check has been carried out and will be presented in the CUSC Panel on 12 December requesting this be treated as an urgent modification to proceed under a timetable agreed by the Authority (with an Authority decision). On 19 December 2025 the Authority rejected that CMP466 should be progressed on an urgency basis and should follow the standard timeline set out in the Panel's letter. (05/02/2025) At the CUSC Panel held on 30 January, the Panel discussed that CMP456 should be assigned as a high priority. Majority of Panel members agreed that the unexpected financial impact to generators along with a simplistic solution meant this could be progressed quickly and align with GC0168.
Details
Timeline
Analysis
CMP456 creates a cost recovery mechanism for generators required to produce Electro Magnetic Transient (EMT) models under GC0168, shifting the financial burden from plant operators to system users. The modification addresses 'significant' costs imposed on older generators with multiple discrete systems who gain no direct benefit from producing these grid stability models. Authority rejected urgent processing in December 2024, with the CUSC Panel designating this high priority in January 2025.
Why it matters
This socialises the cost of grid stability analysis from those who own legacy plant to all system users, creating a precedent that generators should not bear the cost of compliance with new technical requirements. The modification acknowledges that EMT modelling benefits system operation rather than individual generators, as such treating it as a common service funded collectively.
Key facts
- •CMP456 raised 19 June 2024
- •Authority rejected urgent processing on 19 December 2024
- •CUSC Panel designated high priority in January 2025
- •Linked to GC0168 EMT model submission requirements
- •Targets legacy plant with multiple discrete systems