Users of the transmission system are subject to three types of transmission charges:
- Connection charges
- Transmission Network Use of System (TNUoS) charges
- Balancing Services Use of System (BSUoS) charges.
Each type of charge is payable to National Grid Electricity Transmission plc (NGET) in its role as system operator.
Connection charges recover the cost of providing and maintaining connection assets. NGET defines connection assets as those assets solely required to connect an individual user, eg a generator, to Britain’s transmission system, which are not and would not normally be used by another connected party. The costs of these assets are recovered directly from the user. These connection charges do not recover costs associated with assets that are shared (or could potentially be shared) by more than one user.
Transmission Network Use of System charges
Transmission Network Use of System (TNUoS) charges recover the cost of providing and maintaining shared (or potentially shared) electricity transmission assets, ie assets that cannot be solely attributed to a single user. TNUoS charges are recovered from all generation and demand users of Britain’s electricity transmission system. These charges vary by location, reflecting the costs that users impose on the transmission network to transport their electricity.
Balancing Services Use of System charges
Balancing Services Use of System (BSUoS) charges relate to the costs of the day-to-day operation of the transmission system. These costs primarily relate to the balancing of Britain’s electricity system and include the costs of constraining generation.
Charging methodologies and governance
In terms of charging, the design and maintenance of the relevant charging methodologies is enforced through licence conditions, which contain relevant objectives for the methodologies.
The charging methodologies used to derive the charges for connection to and use of the transmission system are administered by NGET in its role as system operator. These methodologies are contained in section 14 of the Connection and Use of System Code (CUSC) industry code.
NGET has responsibility through its electricity transmission licence to ensure that these methodologies are kept up to date. As part of this it must bring forward modifications, where appropriate, that better meet the relevant objectives set out in their licence. There are open governance arrangements that allow industry parties to propose modifications to these methodologies.
Industry assesses these proposals before submitting a recommendation to us. We make the final decision whether to implement any change. We do not set or approve the level of individual charges.