National Grid ESO (NGESO) trades on interconnectors to adjust the flow of electricity into or out of Great Britain to help manage system issues such as Rate Of Change Of Frequency (ROCOF), thermal constraints or to manage energy requirements such as upwards and downwards margin. Trades take place on IFA, BritNed, and NEMO interconnectors. This has been extended to IFA2.

We invite qualified counterparties into NGESO Interconnector (IC) auctions which run ad hoc across the day. The counterparties, who hold respective interconnector capacity or be able to secure the capacity later on, can bid in the auction based on the requirement. Requirements are not firm and are subject to change depending on prevailing system conditions. When the auction has been concluded, the information for a given requirement (lot) will be updated to include the volumes secured on each interconnector, the best price, the volume-weighted average price (VWA), and the clearing price. The requirement may not be completely filled.

To participate in this market, a counterparty is required to have a Grid Trade Master Agreement (GTMA) in place with NGESO and to have access to capacity on channel interconnectors, along with being registered with the BSC party.