Removing 50MW Limit on Individual CMUs in a Portfolio

This page provides full details of the proposed change, relevant dates and decisions.

What is the issue?

Rule 13.4.1B(b) prevents any CMU with aggregate connection capacity greater than 50MW from being part of a CMU Portfolio. 

The 50MW limit was intended by the original CM Expert Group (CMEG) to limit the aggregation of Generating Units (GU) on different sites (e.g. embedded generation) into a single CMU; the CM Rules then initially provided for similar controls but limited them to Existing Generators before extending this to Prospective Generators too. 

It therefore appears that the use of the 50MW limit for CMUs in a CMU Portfolio for SPDs is not related to the 50MW limit for CMUs within the Regulations and CM Rules. 

CP378 seeks to amend Rule 13.4.1B to remove the 50MW limit to allow Capacity Providers to aggregate delivered capacity across a group of Capacity Committed CMUs with the same Capacity Provider to allow for better flexibility in meeting the SPD obligation by delivering as a CMU Portfolio. 

What is the proposed solution?

To amend the CM Rules to remove the 50MW connection capacity limit on CMUs being part of a CMU Portfolio; and

Introduce a limit on each CMU within a CMU Portfolio to deliver a minimum proportion of the CMUs individual Capacity Obligation (to apply to all CMU Portfolios)