Open letter on National Grid Electricity System Operator’s (NGESO) interpretation of use and reclassification of assets at a Grid Supply Point where a party connects to a Tertiary Winding

Tertiary Connections are direct connections to the electricity transmission network via Tertiary Windings on Super Grid Transformers at Grid Supply Points. National Grid Electricity System Operator (NGESO) published an open letter on 28 September 2020 outlining their interpretation of the Connection & Use of System Code (CUSC) in relation to Tertiary Connections in the context of charging. This letter outlines our views on this issue, having taken into account NGESO’s rationale, the potential impacts of their interpretation, and concerns raised to us by National Grid Electricity Transmission (NGET).