Legally, a modification to the Connection and Use of System (Cusc) rules, now agreed by Ofgem, will introduce the concept of a ‘virtual lead party’ (VLP). This is the route by which parties that are currently not participating in the BM can access it and can also participate in the Europe-wide reserve market (known as Terre). From 6 December VLPs will be able to register secondary sources to provide services in these two markets; the new rule also allows those secondary units to be aggregated independently of their supplier, so distributed generation, aggregators and consumers will be able to register and participate directly in Terre and the BM.

In practical terms, NGESO expects that various process changes required in its own and settlemet company Elexon’s systems will shortly be completed and the BM will be ready to receive market participants from 11 December.

The ESO warns, however, that “as with all of our IT projects which involve updates to our Control Room systems, these changes are dependent on favourable conditions on the system at the time”. NGESO has completed  testing with an initial group of market participants, who will create their own web-based application programming interfaces (APIs).