Metering Systems Compliance with BSC Codes of Practice |
Guidance Note |
The definition of a Metering System and an Asset Metering System;
The rules regarding compliance with the Balancing and Settlement Code (BSC) Codes of Practice (CoPs); and
The purpose of Metering Dispensations
What is a Metering System?
A
Metering System, or
Asset Metering System, registered for
Settlement, or
Balancing Services, purposes, in accordance with
Section K, is made up of items of
Metering Equipment including:
Voltage transformers
Current transformers
Meters and Outstations, or Asset Meters (as applicable)
The wires and connections between each item
Connections required to transfer metered data to the outside world (e.g. modems and communication lines).
There are three types of Metering System:
Those which measure and record electrical energy flow for each half hour for Settlement (Half Hourly Metering Systems);
Those which measure and record over longer periods of time, from which energy flows in each half hour can be estimated (Non Half Hourly Metering Systems);
Those which measure and record electrical energy flow for each half hour for Settlement of Secondary Balancing Mechanism Units (BMU) using Asset Metering Systems..
Metering Systems measuring flows to and from the Transmission System or between Distribution Systems, and a few Metering Systems measuring flows at particular sites embedded in Distribution Systems, are registered in the Central Meter Registration System (CMRS) and are often referred to as Central Volume Allocation (CVA) Metering Systems.
These Metering Systems record Half Hourly (HH) data. With the exception of Asset Metering Systems, all other Metering Systems measuring flows at sites embedded in Distribution Systems are registered in a Supplier Meter Registration System (SMRS) and are referred to as Supplier Volume Allocation (SVA) Metering Systems. Only those SVA Metering Systems measuring flows off a Distribution System which are less than 100kW, or flows onto a Distribution System which are less than 30kW, may be Non Half Hourly (NHH) Metering Systems provided they would not have been registered against Profile Classes 5-8 since the implementation of P272. All other SVA Metering Systems must be HH Metering Systems.
In relation to an Unmetered Supply, Equivalent Meters are the hardware and software used to calculate the HH consumption of electricity associated with such Unmetered Supply.
For Metering Systems measuring the flow of electricity to or from an Asset, these are registered in the Asset Meter Registration Service (AMRS) and are referred to as Asset Metering Systems. Asset Metering Systems must be HH Metering Systems.
What is the purpose of a Metering System?
A Metering System accurately records the flow of electricity. For example, it may record the energy flowing into (Import), or away from (Export), a site connected to the Transmission System or a Distribution System or it may record energy flowing between two Systems or in the case of an Asset Metering System an Asset. This recorded data is submitted into the central BSC systems and used to calculate energy imbalance charges for BSC Parties who use more or less energy than they contract to buy or sell.
Suppliers, Asset Metering Virtual Lead Parties, Generators, Licensed Distribution System Operators, the National Electricity Transmission System Operator, Interconnector Administrators and Elexon also use this data for other charging purposes, both within and outside the BSC arrangements. For example: Transmission and Distribution Use of System Charges; allocation between Interconnector Users; Balancing Services delivery, monitoring and payments; Climate Change Levy calculations; and Renewables Obligation performance.
Section K of the BSC sets out participant responsibilities for registering both
Import and
Export Metering Systems or
Asset Metering Systems, and those which measure flows between
Systems at
Systems Connection Points.
Section L sets out the obligations for participants (
Registrants) who register
Metering Systems in
Settlement or for the purposes of
Balancing Services using
Asset Metering Systems in Secondary BMUs. It stipulates that
Registrants must ensure that the
Metering Systems for which they are responsible are installed, commissioned, maintained and tested in accordance with the relevant
Code of Practice (CoP) at the time that
Metering System is first registered in
Settlement.
These obligations on the Registrant are normally carried out by its appointed agent, a Meter Operator Agent (MOA). Where measurement transformers (i.e. current transformers and voltage transformers) are owned by a BSC Party, such as a Licensed Distribution System Operator, they are responsible for the commissioning of the measurement transformers. Where measurement transformers are not owned by a BSC Party then the obligation for commissioning falls on the Registrant, via its appointed agent (i.e. a MOA).
What is a Code of Practice (CoP)?
The CoPs set out the minimum engineering and data requirements that Metering Systems must adhere to in order to be classified as compliant Metering Systems under the BSC. There are various metering CoPs (CoP1, CoP2, CoP3, CoP5, CoP6, CoP7 and CoP10 for HH Metering Systems, CoP8 and CoP9 for NHH Metering Systems, and CoP11 for Asset Metering Systems) each of which caters for different maximum rates of electricity flow. CoP4 is different as it sets out the minimum requirements for calibrating, testing and commissioning the Metering Equipment installed in Metering Systems under all the other CoPs, with the exception of CoP11.
CoP11 sets out the minimum engineering requirements for different maximum rates of electricity flow where they are defined for a particular Asset Metering Type. The minimum requirements for calibrating, testing and commissioning the Metering Equipment installed in Asset Metering Systems is set out in CoP11.
Material change to an item of Metering Equipment
From time to time, items of Metering Equipment need replacing due to damage, failure or simply because they become obsolete and cannot be maintained. The BSC sets out rules for replacing Metering Equipment. The general principle is that when replacing Metering Equipment, the most up to date specifications are used. This means that the latest version of the relevant CoP applies.
Section L3.3 of the BSC stipulates that where any ‘material change’ to an item of
Metering Equipment occurs, then that item of
Metering Equipment must be compliant with the version of the relevant CoP current at the time of the change. A change is not a ‘material change’ when a repair, modification or replacement of any component is not a substantial part of the
Metering Equipment. For example, where the MOA identifies and replaces a faulty mechanical register on a CoP1
Meter.
An example of a material change is where a MOA identifies a faulty Meter and replaces it with another Meter. The replacement Meter (identical or of a different type) must be compliant with the latest version of the relevant CoP.
Material change to a Metering System
A Metering System is comprised of items of Metering Equipment. In addition to the BSC definition of a material change to an item of Metering Equipment, the current versions of CoPs 1, 2 and 11 contain a definition of what constitutes a material change to a Metering System or Asset Metering System. A material change to a Metering System or Asset Metering System would result in the need to ensure that all items of Metering Equipment comprising that Metering System or Asset Metering System are compliant with the latest version of the relevant CoP. These material changes to a Metering System or Asset Metering System are described as a change to:
1. Switchgear containing measurement transformers; and/or
2. The primary plant associated with the Metering System or Asset Metering System, i.e. measurement transformers.
In contrast, the replacement of a Meter or Outstation, or Asset Meter, would not be material to the Metering System or Asset Metering System and would only require the replacement Meter or Outstation, or Asset Meter, to be compliant with latest version of the CoP (i.e. a material change to an item of Metering Equipment).
What is a Metering Dispensation?
If, for practical and/or financial reasons, any Metering Equipment comprised within a Metering System does not meet the requirements set out in the relevant CoP, the Metering Equipment or Metering System may be the subject of an application for a Metering Dispensation from that relevant CoP.
BSC Procedure BSCP32 sets out the process to follow when applying for a
Metering Dispensation.
Metering Dispensations are classified against a number of criteria. Each Metering Dispensation will have an associated term (‘temporary’ or ‘lifetime’) and location (‘site specific’ or ‘generic’).
As the name suggests, site specific Metering Dispensations apply to non-compliant Metering Equipment used, or to be used, at a particular site. The non-compliant Metering Equipment may be comprised in one, or more, Metering Systems, or will be, if not yet registered for Settlement purposes.
An example of where a lifetime, site specific,
Metering Dispensation for
Metering Equipment might be granted would be if, for practical reasons, the measurement transformers associated with the
Metering System(s) cannot be located at the Defined
Metering Point (DMP) set out in the relevant CoP. In other words, the Actual
Metering Point (AMP) and DMP do not coincide. Where accuracy compensation for power transformer and/or cable/line losses and/or busbar losses is required to be applied to meet the overall accuracy limits of error at the DMP, the
Registrant of such
Metering System(s), or prior to the appointment of a
Registrant of such
Metering System(s), Elexon, could apply for a
Metering Dispensation. In this case, the proposed compensation values need to be validated in accordance with
BSCP32, recorded and supporting evidence to justify the accuracy compensation criteria shall be available for inspection by the BSC
Panel or
Technical Assurance Agent. In cases where accuracy compensation for power transformer and/or cable/line and/or busbar losses is
not required to be applied to meet the overall accuracy limits of error at the DMP, a
Metering Dispensation is
not required. In this case, the values of the overall accuracy calculation need be recorded and evidence to justify no accuracy compensation being required, including wherever possible calibration test certificates, need to made available for inspection by the BSC
Panel or
Technical Assurance Agent.
Generic Metering Dispensations apply to specific items of Metering Equipment which may be used to form any number of Metering Systems, subject to the conditions of that Metering Dispensation.
An example of where a lifetime, generic, Metering Dispensation for an item of Metering Equipment might be granted would be if a MOA had purchased a number of CoP compliant Meters and, before this store of Meters had been used up, a new version of a CoP became effective. If the Meters did not meet certain requirements in the new CoP then a Balancing and Settlement Code (BSC) Party (or Elexon, on behalf of a non-BSC Party) could apply for a lifetime, generic, Metering Dispensation for that Meter type against those specific requirements of that new version of the CoP. If granted, the MOA could continue to install those specific Meter types in new or existing sites subject to the conditions of the Metering Dispensation (e.g. only for a period of one year after the new version of the CoP became effective).
BSC Parties can contact Elexon before applying for a Metering Dispensation to get further guidance. Non-BSC Parties can also contact Elexon before asking Elexon to apply for a Metering Dispensation on their behalf.
The BSC
Panel, or in limited circumstances, Elexon, can accept or reject a
Metering Dispensation application. The BSC
Panel has delegated responsibility for accepting or rejecting
Metering Dispensation applications to the
Imbalance Settlement Group (ISG) and/or the
Supplier Volume Allocation Group (SVG).
Elexon can only approve a Metering Dispensation in limited circumstances where two, or more, Metering Systems are to be registered separately behind a single point of connection to the Total System and the Metering System requires compensation to be applied to meet the overall accuracy limits of error at the DMP.
Applications are considered individually. An approved
Metering Dispensation can be rendered void if it is shown that the applicant failed to seek the views of any Affected party (defined in
BSCP32). If the BSC
Panel believe at any time that relevant circumstances have changed they may withdraw or amend a
Metering Dispensation. If a
Metering Dispensation is rendered void; or has been agreed for a limited period and that period has expired; or it has been agreed on conditions that certain circumstances will subsist, and any of those circumstances shall cease to apply, then the applicant can submit another application. Any such modifications to, or extensions of, existing
Metering Dispensations that do not result from any changes to the
Metering Equipment should be identified as updates. Where there are changes to
Metering Equipment then a new application must be made.
How can you prove compliance with the relevant Code of Practice?
In order to confirm that a
Half Hourly Meter/
Asset Meter/
Outstation is compliant with the relevant Issue of a CoP, the item of
Metering Equipment must go through compliance testing in accordance with the processes set out in
BSCP601. If an item of
Half Hourly Metering Equipment passes all the relevant tests in
BSCP601, it will be considered proven against the requirements of the relevant CoP. In most cases the applicant who submits the
Half Hourly Meter/
Asset Meter/
Outstation for testing is the
Half Hourly Meter/
Asset Meter/
Outstation manufacturer.
If all these tests are passed, Elexon issues a certificate of compliance to the applicant for the particular Issue of the CoP that the item was tested against. If the item of
Metering Equipment fails any tests then an applicant can either address the issue(s) and re-do the testing or seek a
Metering Dispensation (through a BSC
Party (or Elexon)), which, if granted, allows its use in
Settlement despite those failings. The BSC allows
Metering Dispensation applications from
Registrants, the BSC
Panel or non-BSC Parties, where Elexon would raise a
Metering Dispensation on behalf of the BSC
Panel or a non-BSC
Party. The process for applying for a
Metering Dispensation is described in
Section L3.4 and in further detail in
BSCP32. There is a list of approved
Meter types and Protocol Approvals on the
CoP Compliance and Protocol Approvals page of the
BSC Website.
In addition to HH Meters/Asset Meters/Outstations being tested for compliance with a HH CoP, the HH Meter/Asset Meter/Outstation must be tested to ensure an approved communications protocol is used before a protocol approval certificate is issued. This ensures that the relevant metering data stored in the Outstation or Asset Meter can be collected from the Metering System by authorised parties (i.e. HH Data Collectors, the Central Data Collection Agent, and Asset Metering HH Data Collectors) and passed into the Settlement process. It is up to the Registrant (Supplier) to satisfy themselves that the protocol used for communicating with NHH Metering Equipment is suitable so that any remotely retrieved NHH data can be used in Settlements.
Installation of compliant Metering Equipment
Once both these certificates are issued, a Registrant can then install that particular HH Meter/Asset Meter/Outstation in either:
any existing HH Metering System or Asset Metering System, as applicable, where there has not been a material change to the Metering System but there has been a material change to the item of Metering Equipment; or
any new HH Metering System or Asset Metering Systems, as applicable, installations as long as the issue of the CoP for which it is compliant is still the current Issue of that CoP when that Metering System is first registered4 in Settlement.
How is on-going compliance measured?
The
Technical Assurance Agent (TAA) is a
BSC Agent who monitors compliance by Parties, in respect of the requirements of
Section L7 of the BSC, the Half Hourly
CoPs and relevant
BSCPs, for their registered
Half Hourly Metering Systems. Compliance is determined via
On-Site Inspections and
Desktop Audits where a number of sites (as determined by the
Performance Assurance Board) are randomly selected in accordance with
BSCP27.
Non-compliances are reported to the
Registrant (and relevant participants like the MOA and
Data Collector) and Elexon. The
Registrant is required to rectify all non-compliant
Metering Systems.
BSCP27 further splits non-compliances into six categories:
NC: A non-compliance has been identified through the Consumption Data Comparison Check, that is deemed to be currently affecting the quality of data for Settlement purposes;
Category 1 Non-Compliance: A non-compliance has been identified from an On-Site Inspection, which is deemed to be currently affecting the quality of data for Settlement purposes;
Category 2 Non-Compliance: A non-compliance has been identified from an On-Site Inspection, which is deemed to have the potential to affect the quality of data for Settlement purposes;
Category A Non-Compliance: A non-compliance has been identified from a Desktop Audit, which is deemed to be currently affecting, or has a high likelihood of affecting, the quality of data for Settlement purposes;
Category B Non Compliance: A non-compliance has been identified from a Desktop Audit, which has been deemed to have a lower likelihood of affecting the quality of data for Settlement purposes, or for the non-provision of evidence; and
Observation: A non-compliance has been identified which is deemed neither to affect nor to have the potential to affect the quality of data for Settlement purposes.
What happens when a Code of Practice changes?
The CoPs are subject to
change as is the BSC and its other
Code Subsidiary Documents.
BSC Parties can raise
Modifications which are determined by the BSC
Panel. BSC Parties or Elexon can raise
Change Proposals which are determined by the BSC
Panel or a
Panel Committee with delegated authority. Any approved changes to the CoPs will result in a new version of the relevant CoP. Any changes that materially affect the requirements for
Meters and/or
Outstations will result in a new Issue (and version) of the relevant CoP. Therefore, the
Registrant has to ensure that for any new installations all the items of
Metering Equipment used to make up the new
Metering System are compliant with the latest Issue (and version) of the relevant CoP. The
Registrant also has to ensure materially changed
Meters and/or
Outstations, installed at existing sites, are replaced with
Meters and/or
Outstations that are compliant with the latest Issue (and version) of the relevant CoP.
A timeline showing the previous versions of each CoP is available on the Amendment Record within the relevant
Codes of Practice on the
BSC Website.
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