The Split of National Grid’s Transmission Owner (TO) and System Operator (SO) Roles and Licences
The Split of National Grid’s Transmission Owner (TO) and System Operator (SO) Roles and Licences

The following Energy guidance note provides comprehensive and up to date legal information covering:

  • The Split of National Grid’s Transmission Owner (TO) and System Operator (SO) Roles and Licences
  • Background
  • Publications to date
  • NGET TO Licence
  • NGESO Licence
  • Consequential industry codes amendments—the STC
  • Consequential industry codes amendments—the CUSC
  • Consequential industry codes amendments—the BSC
  • Consequential industry code amendments—the Grid Code
  • Unbundling certification

Background

For a full overview of the nature and roles of the various companies in the National Grid plc group, see Practice Note: The role of National Grid in the Great Britain energy market.

However, for the purposes of this Practice Note the key point is that, prior to 1 April 2019, the National Grid plc subsidiary, National Grid Electricity Transmission plc (NGET), was both:

  1. owner of the onshore high voltage electricity transmission system (NETS) in England and Wales and responsible for its maintenance (this is often referred to as being ‘Transmission Owner’ (TO)), and

  2. across the whole GB onshore and offshore NETS, is responsible for balancing electricity flowing onto the NETS with electricity flowing off it, entering into contractual connection agreements for those connecting to the NETS, and applying charges to NETS users (this is often referred to as being ‘System Operator’ (SO))

This was underpinned by NGET owning the physical England and Wales onshore NETS and holding a single licence (issued to it by Office of Gas and Electricity Markets (Ofgem) pursuant to section 6(1)(b) of the Electricity Act 1989 (EA 1989)) providing for NGET to perform both the above activities and to charge for them in accordance with a price controlled process. The previous transmission licence comprised two sets of conditions:

  1. the Standard Conditions (which applied to all