CMP456 Connection and Use of System Code (CUSC) urgency decision

Publication type:
Code modification
Publication date:
Topic:
Electricity transmission
Subtopic:
Connections

Outcome of request for an urgent review of proposed changes to Connection and Use of System Code (CUSC), CMP456 Cost recovery for legacy plant in relation to GC0168.

Details of outcome

We have rejected the request to treat CMP456 as urgent.

Code modification description

On 29 October 2025, RWE (the ‘Proposer’) raised CMP4561 (‘the Proposal’). CMP456 seeks to amend the Connection and Use of System Code (CUSC) to provide a cost-recovery mechanism for existing generators that may be required to develop Electromagnetic Transient (EMT) models retrospectively following potential changes to the Grid Code. EMT models are used by the system operator to assess system stability as the electricity system evolves.

We consider that CMP456 can be progressed through the standard CUSC governance process.