CONTENTS
Baselining Methodology Document
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Version | Date Approved | Description of release | Changes Included | Committee |
1.0 | 06/08/21 | 23 February Standard Release 2023 | P376 | P314/06 |
2.0 | 13/09/24 | 01 October 2024 Non-Standard Release | ORD009 | Directed by Secretary of State |
Lead Parties of BM Units participating in the Balancing Mechanism are required by the BSC (and Grid Code) to submit Physical Notifications to the NETSO. These provide the Lead Party’s best estimate of the MW level of demand or generation that the BM Unit will deliver (in the absence of any Bid Offer Acceptance issued by the NETSO).
The Physical Notification in force at Gate Closure becomes a Final Physical Notification (FPN). The NETSO is required to send the FPN to the Balancing Mechanism Reporting Agent (BMRA) for reporting to the market, and to the Settlement Administration Agent (SAA) for use in Settlement.
The SAA compares the FPN to the BM Unit Metered Volume, in order to verify that the BM Unit has delivered the Bid Offer Acceptance instructed by the NETSO.
The Lead Party must still submit Physical Notifications to the NETSO (who will continue to use them for purposes of despatch).
The Supplier Volume Allocation Agent (SVAA) will use historical metered data to calculate MSID Baseline Values for some or all of the MSID Pairs and/or AMSID Pairs in the BM Unit, in accordance with the Baselining Methodology specified in this document. The Lead Party may choose which of the MSID Pairs and AMSID Pairs within the BM Unit (known as “Baselined MSID Pairs” or “Baselined AMSID Pairs”) SVAA should perform this calculation for.
If there are non-Baselined MSID Pairs or AMSID Pairs in the BM Unit, the Lead Party must provide SVAA with a Submitted Expected Volume. This is equivalent to a Final Physical Notification, but only includes those MSID Pairs (and AMSID Pairs) in the BM Unit that are not Baselined MSID Pairs (or AMSID Pairs).
If an MSID Pair or AMSID Pair has been declared as Baselined, but SVAA is unable to calculate a Baseline Value (due to lack of historic metered data), the Baseline Value will default to the actual Half Hourly meter reading in that Settlement Period. The effect of this is that the MSID Pair or AMSID Pair will be assumed (for purposes of Settlement) not to have contributed to delivery of any Acceptance by the BM Unit. However, this may be corrected in a subsequent Reconciliation Run, if the metered data required to calculate a Baseline Value has become available by that point.
If a VLP knows in advance that there will be insufficient data to calculate a Baselined Value for an MSID Pair or AMSID Pair (and does not wish to include it in their Submitted Expected Volume) they may declare it as “Inactive”. An MSID Pair or AMSID Pair cannot participate in the Balancing Mechanism while it remains Inactive, but SVAA will continue trying to calculate Baseline Values for it, and inform the VLP when there is sufficient data to do so (at which point they may elect to change it from Inactive to Baselined). Note that the option of declaring MSID Pairs to be Inactive is not available for Supplier BM Units (only VLP’s Secondary BM Units).
SVAA will aggregate the Submitted Expected Volume and all of the MSID Baseline Values to derive a Settlement Expected Volume (SEVij) (for each Baselined BM Unit and Settlement Period). SVAA will send the Settlement Expected Volume to SAA, who will use it (in place of the FPN) to verify that the BM Unit has delivered the Bid Offer Acceptance instructed by the NETSO.
By a centrally-appointed BSC Agent, using a Panel-approved methodology (providing assurance to all affected Parties that the calculation has been performed in an independent and unbiased way); and
Using up-to-date metered data that would not have been available to the Lead Party in advance (allowing for a more accurate estimate of the baseline).
Baselined Entity | Name for calculated Baseline Value |
Metering System in Baselined MSID Pair | MSID Baseline Value (MBVKiLj) |
Metering System in Baselined AMSID Pair | AMSID Baseline Value (AMBVKiLj) |
Asset Differencing scheme (i.e. the net Import of all MSID Pairs and AMSID Pairs involved in a given instance of Asset Differencing) | Net Differencing Baseline Value (NDBVij) |
Baseline Calculations (as specified in this document)
SVAA;
Virtual Lead Parties;
Suppliers; and
BSC Panel
AMVLP | Asset Metering Virtual Lead Party |
BMRA | Balancing Mechanism Reporting Agent |
BSC | Balancing and Settlement Code |
FPN | Final Physical Notification |
HHDA | Half Hourly Data Aggregator |
NETSO | National Electricity Transmission System Operator |
SAA | Settlement Administration Agent |
SVAA | Supplier Volume Allocation Agent |
VLP | Virtual Lead Party |
Acceptance | Has the meaning given to that term in Annex X-1 of the BSC. |
Additional BM Unit | Has the meaning given to that term in Annex X-1 of the BSC. |
AMSID Baseline Value | Has the meaning given to that term in Annex S-2 of the BSC. |
AMSID Pair | Has the meaning given to that term in Annex X-1 of the BSC. |
Asset Differencing | Has the meaning given to that term in Annex X-1 of the BSC. |
Asset Metering Virtual Lead Party | A Virtual Lead Party (VLP) who has Qualified (in accordance with BSCP537) to register Asset Metering Systems and allocate AMSID Pairs to Secondary BM Units. |
Balancing Service | Has the meaning given to that term in the ESO Licence. |
Baseline Value | An MSID Baseline Value, AMSID Baseline Value or Net Differencing Baseline Value. |
Baselined AMSID Pair | Has the meaning given to that term in Annex X-1 of the BSC. |
Baselined BM Unit | Has the meaning given to that term in Annex X-1 of the BSC. |
Baselined Entity | A Metering System or Metering System(s) for which paragraph 7.3.1 of BSC Annex S-2 requires Baseline Values to be calculated. A Baselined Entity may be either:
|
Baselined Entity Metered Volume | In relation to a Baselined Entity to which Approved Baselining Methodology BL01 applies, the net Import of the Baselined Entity (in a historical Settlement Period), calculated in accordance with section 3.4.2 of this Baselining Methodology Document. |
Baselined MSID Pair | Has the meaning given to that term in Annex X-1 of the BSC. |
Baselining Methodology | Has the meaning given to that term in Annex X-1 of the BSC. |
Baselining Methodology Document | Has the meaning given to that term in Annex X-1 of the BSC. |
BSC Auditor | Has the meaning given to that term in Annex X-1 of the BSC. |
BSCCo | Has the meaning given to that term in Annex X-1 of the BSC. |
Eligible Day | An historical Settlement Day which meets certain criteria allowing data from that day to be used in the calculation of MSID Baseline Values. For Approved Baselining Methodology BL01, the criteria for a Settlement Day to be an Eligible Day are defined in section 3.4.1 of this Baselining Methodology Document. |
Event Day | A Settlement Day affected by any of the circumstances listed in Appendix A of this Baselining Methodology Document, about which the Lead Party has notified SVAA in accordance with BSC Procedure BSCP602. |
Gate Closure | Has the meaning given to that term in Annex X-1 of the BSC. |
Inactive AMSID Pair | Has the meaning given to that term in Annex X-1 of the BSC. |
Inactive MSID Pair | Has the meaning given to that term in Annex X-1 of the BSC. |
In Day Adjustment | An additive adjustment to the baseline, used to adjust its level to more closely match outturn demand on the given Settlement Day. For Approved Baselining Methodology BL01, the calculation of the In Day Adjustment is defined in section 3.4.3 of this Baselining Methodology Document. |
In Day Reference Window | A period immediately prior to despatch of a BM Unit, used to calculate an In Day Adjustment for each Baselined Entity within that BM Unit. For Approved Baselining Methodology BL01, the In Day Reference Window is three hours long, as defined in section 3.4.3 of this Baselining Methodology Document. |
MSID Baseline Value | Has the meaning given to that term in Annex S-2 of the BSC. |
MSID Pair | Has the meaning given to that term in Annex X-1 of the BSC. |
Net Differencing Baseline Value | Has the meaning given to that term in Annex S-2 of the BSC. |
Non-Working Day | A Settlement Day that is not a Working Day. |
Participant Management Platform | An IT system established by Elexon that (among other functions) allows the SVAA to record notifications of MSID Pairs submitted by Suppliers and Virtual Lead Parties. |
Secondary BM Unit | Has the meaning given to that term in Annex X-1 of the BSC. |
Settlement Day | Has the meaning given to that term in Annex X-1 of the BSC. |
Settlement Period | Has the meaning given to that term in Annex X-2 of the BSC. |
Technical Assurance Agent | Has the meaning given to that term in Annex X-1 of the BSC. |
Unadjusted Baseline Value | In relation to a Baselined Entity to which Approved Baselining Methodology BL01 applies, the baseline value calculated by SVAA, prior to applying the In Day Adjustment. This is an intermediate data item within the BL01 methodology, calculated in accordance with section 3.4.2 of this Baselining Methodology Document. |
Virtual Lead Party | Has the meaning given to that term in Annex X-1 of the BSC. |
Working Day | Has the meaning given to that term in Annex X-1 of the BSC. |
Details of the Baselined Entities for which data is to be calculated (and the Baselined BM Unit to which each Baselined Entity belongs). This data is notified to SVAA by the Lead Party in accordance with BSC Procedure BSCP602.
The metered data for each Baselined Entity. Metered data is required for the Settlement Day D, and as many as possible of the previous sixty Settlement Days. If insufficient Metered Data is available, it may not be possible to calculate Baseline Values (in which case the Baseline Value will be set equal to the Metered Data for that Settlement Period, effectively deeming there to have been no volume delivered). The source of this metered data depends upon the type of Baselined Entity:
For MSID Pairs, Metering System Metered Consumption (VMMCHZaNLKji) values are required for each of the SVA Metering System(s) in the MSID Pair. The VMMCHZaNLKji values are in MWh, and are calculated by SVAA from metered data provided by Half Hourly Data Aggregators (HHDAs). The process for provision of metered data to SVAA by HHDAs is described in BSC Procedure BSCP503 (‘Half Hourly Data Aggregation for SVA Metering Systems Registered in SMRS’);
For AMSID Pairs, Asset Metering System Metered Consumption (VMMCHNLKj) values are required for each of the Asset Metering System(s) in the AMSID Pair. The VMMCHNLKj values are in MWh, and are calculated by SVAA from metered data provided by Half Hourly Data Collectors (HHDCs). The process for provision of metered data to SVAA by HHDCs is described in BSC Procedure BSCP502 (‘Half Hourly Data Collection for SVA Metering Systems Registered in SMRS’); and
For Asset Differencing, the required metered data are Net Differencing Volume (VNDKj) values calculated by the SVAA in accordance with BSC Annex S-2 paragraph 7.1.1C.
Details of which Settlement Periods (if any) each Baselined BM Unit received an Acceptance from the NETSO. This information is sent to SVAA each day by the Settlement Administration Agent (the Daily Activations Report).
Details (for each MSID Pair or AMSID Pair) of Settlement Days which should be treated as Event Days. These details are notified to SVAA by the Lead Party in accordance with BSC Procedure BSCP602
A Boolean (True or False) indicator of whether there was sufficient metered data available to calculate a Baseline Value. This is required for every Baselined Entity, and is reported to the Lead Party of the BM Unit.
A Baseline Value for each Baselined Entity and Settlement Period. This is required for every Baselined Entity. The Baseline Value must be in units of MWh, and represent an estimate of what the net metered data would have been for the Metering System(s) included in the Baselined Entity, in the absence of any Acceptance from the NETSO. Where insufficient historic data is available to calculate a Baseline Value, the Baseline Value will default to the metered data value for the individual Settlement Period.
Table 1 – Summary of Approved Baselining Methodologies | |||||
Methodology Id | Data range | Selection criteria | Selected data | Working Day | Non Working Day |
BL01 | 60 days | Is a like day (e.g. Working/Non-Working) | Up to 10 days for Working Days, 4 days for Non-Working Days | Straight average over available data | Straight average of middle 2 days |
Identify the required number of previous Settlement Days of the same type (Working or Non-Working) for which metered data is available, as described in section 3.4.1 below. If insufficient days are available, the Baseline Value will default to the metered data for the same Settlement Period (i.e. the Baseline will equal the out-turn metered data), and the Metering System(s) in the Baselined Entity will be reported to the Lead Party as having insufficient data.
For each Settlement Period, calculate an Unadjusted Baseline Value (for the Baselined Entity) by averaging the metered data values of the corresponding Settlement Period in some or all of the previous days identified in step 1. See 3.4.2 below for details of which days are included in the average, and the treatment of clock change days (at the start and end of British Summer Time).
If the BM Unit containing the Baselined Entity was issued with an Acceptance by the NETSO in any Settlement Period of the day, calculate an In Day Adjustment, and add it to the Unadjusted Baseline Value – see section 3.4.3 below. Where no acceptance was issued, a separate In Day Adjustment will be calculated for each Settlement Period of the Settlement Day (purely to facilitate assurance of the Baselining Methodology, not for purposes of Settlement).
Allocate the calculated baseline values to the Import or Export Metering System (depending on whether they are positive or negative) – see section 3.4.4 below.
Are of the same time type (Working Day or non-Working Day) as day D;
Have metered data available for the Baselined Entity, as follows:
For an MSID Pair, VMMCHZaNLKji values must be available for the Import Metering System and (if there is one) the Export Metering System;
For an AMSID Pair, VMMCHNLKj values must be available for the Import Metering System and (if there is one) the Export Metering System; and
For Asset Differencing, values of Net Differencing Volume (VNDKj) must be available.
Have not been notified to SVAA by the Lead Party as being an Event Day for the Baselined MSID Pair or Baselined AMSID Pair (see Appendix A); and
Are not ‘clock change’ days (i.e. the calendar days at the start and end of British Summer Time, currently the last Sunday of March and October).
Table 2 – Selection of Eligible Days for use in calculating the baseline | ||
Day Type | No. of Eligible Days identified in the 60-day window | Historical Settlement Days used to calculate the baseline |
Working Day | Ten or more Eligible Days | Ten most recent Eligible Days |
Working Day | 5 to 9 Eligible Days | All Eligible Days |
Working Day | Less than five Eligible Days | Baseline Values default to out-turn metered data for the Metering System(s) in the Baselined Entity, and they will be reported to the Lead Party as having insufficient data. |
Non-Working Day | Four or more Eligible Days | Four most recent Eligible Days |
Non-Working Day | Less than four Eligible Days | Baseline Values will default to out-turn metered data for the Metering System(s) in the Baselined Entity, and they will be reported to the Lead Party as having insufficient data. |
Calculate the net metered data (“Baselined Entity Metered Volume”) for the Baselined Entity (for each Settlement Period of each historical Settlement Day identified in step 1). These Baselined Entity Metered Volumes represents the net Import for the Baselined Entity (with negative values representing net Export), and are calculated as follows:
For MSID Pairs, subtract the VMMCHZaNLKji value for the Export Metering System (if there is one) from the VMMCHZaNLKji value for the Import Metering System;
For AMSID pairs, subtract the VMMCHNLKj value for the Export Metering System (if there is one) from the VMMCHNLKj value for the Import Metering System; and
For Asset Differencing, the Baselined Entity Metered Volume is equal to the Net Differencing Volume (VNDKj)
Identify the subset of historical Settlement Days (identified in step 1) that will be used to calculate the Unadjusted Baseline Value:
For a Working Day, all of the six to ten Eligible Days identified in step 1 will be used; and
For a Non-Working Day, two of the four Eligible Days identified in step 1 will be used. The two selected will be the middle 2 of the four (ranking them in order of the total Baselined Entity Metered Volume, summed over the Settlement Day)
For each Settlement Period in Settlement Day D, calculate the Unadjusted Baseline Value as the arithmetic mean of the Baselined Entity Metered Volume in the corresponding Settlement Period of each of the historical days identified in step (b).
Settlement Periods 1-2 on Settlement Day D correspond to Settlement Periods 1-2 on the historical Settlement Day;
Settlement Periods 3-4 on Settlement Day D also correspond to Settlement Periods 1-2 on the historical Settlement Day; and
Settlement Periods 5-50 on Settlement Day D correspond to Settlement Periods 3-48 on the historical Settlement Day.
Settlement Periods 1-2 on Settlement Day D correspond to Settlement Periods 1-2 on the historical Settlement Day; and
Settlement Periods 3-46 on Settlement Day D correspond to Settlement Periods 5-48 on the historical Settlement Day.
For an Acceptance in the first three hours of the Settlement Day, the In Day Reference Window will stretch back into the previous Settlement Day (D-1). In this case the calculation of the In Day Adjustment will require Baseline Values and Baselined Entity Metered Volumes for day (D-1) as well as day D.
If the Baselined Entity Metered Volumes and/or Unadjusted Baseline Values required to calculate the In Day Adjustment are not available, SVAA shall set the In Day Adjustment to zero. This is most likely to happen if day D is the first Settlement Day for which data was available to calculate a baseline, but the In Day Reference Window falls partly or wholly into the previous Settlement Day.
If the BM Unit containing the MSID Pair and/or AMSID Pair did not receive any Acceptances from the NETSO on Settlement Day D, there is no Settlement requirement to calculate an In Day Adjustment. But for assurance purposes (to allow monitoring of how well the Baselining Methodology is functioning), SVAA will calculate a separate In Day Adjustment for each Settlement Period of the Settlement Day – see section 3.4.3.1 below.
Where an MSID Pair is dispatched multiple times on the same day, it will not be possible to calculate a second In Day Adjustment, as the data will have been contaminated by the first dispatch. Therefore the same In Day Adjustment will also be applied to the profile shape for any subsequent dispatches.
It is the BSC Panel’s decision whether to review or change the Methodology, but BSCCo or any Supplier or VLP can request them to do so;
The BSC Panel may request assistance from BSCCo e.g. in analysing whether a change is needed;
Unless otherwise agreed by the Panel, changes to the document will be drafted by BSCCo; and
the Panel will consult with Parties in a manner appropriate to the scale and complexity of the changes before agreeing them.
Those identified in BSC Section S13.2; and
Identification of specific generation or demand side response technologies that are not accurately baselined by the existing approved Baselining Methodology (or Methodologies).
Delivery of a Balancing Service;
A Site outage;
Equipment failure; and/or
Site Disconnection.