Balancing Mechanism Units

Balancing Mechanism Units

Balancing Mechanism (BM) Units are used as units of trade within the Balancing Mechanism. Each BM Unit accounts for a collection of plant and/or apparatus, and is considered the smallest grouping that can be independently controlled. As a result, most BM Units contain either a generating unit or a collection of consumption meters. Any energy produced or consumed by the contents of a BM Unit is accredited to that BM Unit.

Systems Connections Points 

A Systems Connection Point is a point of connection between two or more Systems excluding points of connection between Distribution Systems in the same GSP Group or a point of connection between Offshore Transmission System User Assets and the Transmission System. There are three types of Systems Connection Points:

  • Grid Supply Points (GSPs) – these are points of connection between the Transmission System and a Distribution System
  • Offshore Transmission Connection Point (OTCP) – these are a GSP where the Systems Connection Point is between a Distribution System and an Offshore Transmission System. Note, at an OTCP the Metering System is registered by National Grid as opposed to the LDSO
  • Distribution Systems Connection Points (DSCPs) – these are points of connection between two Distribution Systems
  • How are BM Units categorised?

    There are several types of BM Unit, each covering different aspects of the system. Each is marked with a particular prefix to its ID, as shown below:

    BM Unit Prefix Description
    Directly Connected T_ These BM Units are directly connected to the Transmission System.
    Embedded E_ These BM Units are embedded into a Distribution System.
    Interconnector I_ These BM Units are related to an Interconnector.
    Supplier 2_C_ These BM Units cover Supply, and contain all of a particular Supplier’s MPANs in either a Base or Additional Supplier BM Unit for a given Grid Supply Point (GSP) Group.These Additional Supplier BM Units are registered solely for the purpose of allocating CFD Assets to them.
    Miscellaneous M_ Other types of BM Units that don’t fit the above categories. This prefix does not apply to newly registered BM Units.

    A complete list of all active BM Units can be found on the ELEXON Portal.

  • How do I register BM Units?

    The BM Unit Registration process is described in BSCP15 ‘BM Unit Registration‘, which covers the procedures and timescales for registering BM Units. Registering a BM Unit requires a lead time of 30 Working Days, and you will normally need to speak to National Grid before this process begins, so you should leave plenty of time to complete the whole process. You can register BM Units using form BSCP15/4.1, which must be sent to the Central Registration Agent (CRA). Guidance on the BM Unit registration process, including filling in BSCP15/4.1, along with further information about BM Units, can be found in our BM Unit Guidance.

    If you are a new Supplier joining the market, you need to set up 14 Supplier BM Units (your Base BM Units, one for each GSP Group) as part of your registration. You can register all other BM Units on an ad-hoc basis as and when they are required.

    If you looking to register BM Units for Electricity Market Reform (EMR) purposes please see the Registration of BM Units for EMR guidance document. There are no material changes to the registration of BM Units for CFD Assets registered for CMRS. However, there are new registration processes for BM Units registered for CFD Assets registered in SMRS.  For naming convention for Additional BM Units registered for CFD Assets please click here.

  • What are the timescales for registering BM Units?

    Registering a T_, E_ or I_ BM Unit requires a lead time of 30 Working Days and 60 Working Days for a non-standard BM Unit,  you will normally need to speak to National Grid before this process begins, so you should leave plenty of time to complete the whole process. Additionally if a Metering Dispensation needs to be sought for the site, refer to the Metering Dispensations page for the timescales associated with this. A standard BM Unit includes the following:

    • The Export of a Generating Unit, CCGT Module or Power Park Module registered in CMRS
    • A Combined Offshore BM Unit
    • The Imports though the station transformers of a generating plant registered in CMRS
    • Premises (or a customer supplied by a Party) directly connected to the Transmission System at one Boundary Point
    • An Interconnector BM Unit

    Other BM Units may be non-standard and their configuration needs to be agreed by the ISG.  Please contact bm.unit@elexon.co.uk for advice on whether a BM Unit is standard or a non-standard configuration.

    The Go-live date for registering a 2_ or  C_ BM Unit needs to align with the MDD Go-Live Date. These BM Units follow the MDD fast-track process. To register these BM Units, you need to submit MDD forms and a BSCP15/4.1 form. The MDD form needs to be submitted in line with the MDD timetable .  A Supplier BM Unit may also be registered with National Grid. If you have a National Grid BM Unit ID, your BSCP15/4.1 form needs to be submitted at least 30 Working Days before the Go live date. If you are not registering your BM Unit with National Grid and you do not have a National Grid BM Unit ID, your BSCP15/4.1 form needs to be submitted at least 15 Working Days before the Go-live date.

    If you are registering your BM Unit with National Grid, you will need to speak to them to obtain the National Grid BM Unit Id and begin their registration process.

     

  • How do I register for Systems Connection Points?

    The Registration of Systems Connection Points is described in BSCP25 ‘Registration of Transmission System Boundary Points, Grid Supply Points, GSP Groups and Distribution Systems Connection Points’, supported by a number of other BSCPs. Guidance on the Registration of Systems Connection Points including flow diagrams showing how all the BSCPs interlink in the process can be found in the Registration of Systems Connection Points guidance note. This guidance also contains checklists for LDSOs for the registration of GSPs and DSCPs.

    Once all registration requirements associated with the Systems Connection Point are complete, ELEXON will issue an ‘Approval to Energise’ email for the BM Unit. Systems Connection Point should not be registered without receipt of this email from ELEXON.

  • What are the timescales for registering Systems Connection Points?

    The registration of a new GSP needs to be initiated at least five Working Days (WD) before the Commissioning Programme Commencement date. If a Metering Dispensation needs to be sought, refer to the Metering Dispensations page for the timescales associated with this. Metering and Aggregation Rule steps need to be initiated at least 20 WD before the proposed energisation date.

    A new circuit at a GSP and associated Metering and Aggregation Rules need to be registered at least 20 WD before the proposed energisation date, although if a Metering Dispensation needs to be sought, refer to the Metering Dispensation page for the timescales associated with this.

    The registration of a new DSCP or new circuit at a DSCP and associated Metering and Aggregation Rules need to be initiated at least 20 WD before the energisation of the first circuit at the DSCP, although the Line Loss Factors associated with the new DSCP (or any new or changes to Line Loss factors for a new circuit) need to be registered at least 50 WD before the proposed energisation date. If a Metering Dispensation needs to be sought, refer to the Metering Dispensation page for the timescales associated with this.