1. Reference is made to the Balancing and Settlement Code dated Code Effective Date and, in particular, to the definition of “BSC Procedure” in Section X, Annex X-1 thereof.

2. This is BSC Procedure 18, Version 18.0 relating to Corrections to Bid-Offer Acceptance Related Data.

3. This BSC Procedure is effective from 02 April 2024.

4. This BSC Procedure has been approved by the BSC Panel.

Intellectual Property Rights, Copyright and Disclaimer

The copyright and other intellectual property rights in this document are vested in Elexon or appear with the consent of the copyright owner. These materials are made available for you for the purposes of your participation in the electricity industry. If you have an interest in the electricity industry, you may view, download, copy, distribute, modify, transmit, publish, sell or create derivative works (in whatever format) from this document or in other cases use for personal academic or other non-commercial purposes. All copyright and other proprietary notices contained in the document must be retained on any copy you make.

All other rights of the copyright owner not expressly dealt with above are reserved.

No representation, warranty or guarantee is made that the information in this document is accurate or complete. While care is taken in the collection and provision of this information, Elexon Limited shall not be liable for any errors, omissions, misstatements or mistakes in any information or damages resulting from the use of this information or action taken in reliance on it.

AMENDMENT RECORD

Version	Date	Description of Changes	Changes Included	Mods/ Panel/ Committee Refs
1.0	30/06/04	Designated version	CP995
2.0	BETTA Effective Date	BETTA 6.3 rebadging changes for the CVA Feb 05 Release		BETTA 6.3
3.0	02/11/05	CVA Programme November 05 Release	P172	Panel
4.0	05/11/09	November 09 Release	CP1176 (Part)	ISG68/02 SVG67/02
			CP1283	ISG100/01
			P217	Panel 142/06
			P231	Panel 155/04
5.0	04/11/10	November 10 Release	P257	Panel
6.0	31/03/14	Modification P276	P276	ISG154/03
7.0	26/06/14	June 2014 Release	CP1400	ISG151/04
8.0	26/02/15	February 2015 Release	CP1392	ISG149/06
9.0	05/11/15	November 2015 Release	P323	P245/06
10.0	29/03/19	29 March 2019 Standalone Release	P369	P285/12
11.0	27/06/19	June 2019 Release	P367 Self-Governance	SVG219/02 ISG216/01
12.0	11/12/19	December 2019 Standalone Release	CP1517	ISG220/01
13.0	27/02/20	February 2020 Release	P394 Self Governance	P297/07
14.0	24/10/2022	September 2022 Special Release	P447	P330c/01
15.0	07/12/2022	December 2022 Special Release	P448	P330C/02
16.0	29/06/2023	June 2023 Release	CP1580	P338/04
17.0	02/11/2023	November 2023 Release	CP1581	ISG268/04
18.0	02/04/2024	02 April 2024 Special Release	P451	Panel 345/03

1 Introduction

1.1 Scope and Purpose of the Procedure

This BSC Procedure (BSCP) defines the processes that BSCCo, the Settlement Administration Agent (SAA), the National Electricity Transmission System Operator (NETSO) and BSC Parties will use. This is specifically to input corrections to erroneous Final Physical Notification (FPN), Bid-Offer Data (BOD), Bid-Offer Acceptance Level (BOAL)¹ and Bid-Offer Acceptance Level Flagged (BOALF)² data (collectively referred to as the ‘Bid-Offer Acceptance Related Data’) and Replacement Reserve data within the Settlement Administration Agent (SAA) systems or Balancing Mechanism Reporting Agent (BMRA) systems. For the avoidance of doubt, the correction of erroneous Bid-Offer Acceptance Data or Replacement Reserve Data means correcting incorrect data, or removing non-applicable data (e.g. Winter Contingency Offers) or inserting missing data. All changes relating to volume (MW, Time and Duration) are submitted by the NETSO with agreement of the affected BSC Parties (except for Winter Contingency Notifications), and are authorised by BSCCo.

Each Network Gas Supply Emergency Acceptance, which will entered into Settlement using a similar process to Emergency Instructions, will be reviewed after the event by the Generation Curtailment Validation Committee, which may direct changes to FPNs, Bid-Offer Data and/or Acceptance Data relating to the Network Gas Supply Emergency Acceptance. Such changes will implemented in SAA in the next available Settlement Run³. See Appendix 1 for further details of the Settlement process for Network Gas Supply Emergency Acceptances.

This procedure also defines the process that BSCCo, the Settlement Administration Agent and the NETSO will use to input manual corrections to erroneous SO-Flagged data fields within the BOALF data changes are submitted by the NETSO and are authorised by BSCCo, agreement is not required from BSC Parties because they are not directly impacted by a flag change.

This BSCP describes the key interfaces and timetables for inputting changes to the affected BMRA and SAA systems. All corrections to the Bid-Offer Acceptance related data and to Replacement Reserve data must have the consent of the associated BSC Parties (aside from SO-Flag changes, Network Gas Supply Emergency Acceptances and Winter Contingency Notifications) and corrections must be applied before the Initial Settlement Run (SF). If consent, or in the case of Winter Contingency Notification or SO-Flag correction notification from the NETSO, is not received prior to SF then the data corrections must be raised as a Trading Dispute and progressed through the Trading Disputes process in accordance with BSCP11.

1.2 Main Users of the Procedure and their Responsibilities

The main users of this BSCP are:

BSCCo – witness and authorise the correction process for each change made (including SO-Flag changes and Winter Contingency Notifications) and confirm that any corrections made are in accordance with the changes agreed (excluding SO-Flag changes and Winter Contingency Notifications) between the affected BSC Parties and the NETSO.
BSC Parties – confirm that settlement error has occurred and agree to the proposed corrections (excluding SO-Flag changes and Winter Contingency Notifications).
NETSO – submit corrections directly to the SAA for manual update prior to the Initial Settlement Run, except for any Network Gas Supply Emergency Acceptances which must be actioned prior to the Interim Information Settlement Run (II), if notified to the SAA by the end of the second full working day after the relevant Settlement Date. After the Initial Settlement Run (SF), all corrections (except for Acceptance Data relating to Network Gas Supply Emergency Acceptances) must be submitted using the Trading Disputes process detailed in BSCP11.
BMRA – receives corrections via electronic transfer (FTP) directly from the NETSO.
SAA – receives corrections from NETSO or BMRA and determines the most appropriate changes to be made to the database in order to ensure that the data concerning the Bid-Offer Acceptance or Replacement Reserve data accurately reflects the steps taken by the affected BSC Parties and / or the SO-Flag field is correctly reflected in the database.

1.3 Use of the Procedure

The remaining sections in this document are:

Section 2 – Not Used.

Section 3 - Interface and Timetable Information: this section defines in more detail the requirements of each business process.

1.4 Balancing and Settlement Code Provision

This BSCP should be read in conjunction with the BSC and in particular Sections Q, T, U and W. This BSCP has been produced in accordance with the provisions of the BSC. In the event of an inconsistency between the provisions of this BSCP and the BSC, the provisions of the BSC shall prevail.

1.5 Associated BSC Procedures

BSCP01 Overview of Trading Arrangements

BSCP11 Trading Disputes

1.6 Acronyms and Definitions

1.6.1 List of Acronyms

The terms used in this BSCP are defined as follows;

BOA	Bid-Offer Acceptance
BOAL	Bid-Offer Acceptance Level
BOALF	Bid-Offer Acceptance Level Flagged
BOD	Bid-Offer Data
BSAD	Balancing Services Adjustment Data
BSC	Balancing and Settlement Code
BSCCo	Balancing and Settlement Code Company
BSCP	Balancing and Settlement Code Procedure
FPN	Final Physical Notification
II	Interim Information Settlement Run completed 5 Working Days after the Settlement Day
NETSO	National Electricity Transmission System Operator as the holder of the Transmission Licence and any reference to "NETSO", "NGESO", "National Grid Company" or "NGC" in the Code or any Subsidiary Document shall have the same meaning.
Network Gas Supply Emergency Acceptance	an instruction to reduce or discontinue the offtake of gas issued by a Gas Transporter for the purpose of Load Shedding during Stage 2 or higher of a Network Gas Supply Emergency, where the effect of such instruction is to limit the amount of electricity that can be produced by one or more Generating Units within one or more BM Units.
RR	Replacement Reserve
SAA	Settlement Administration Agent
SD	Settlement Day
SF	Initial Settlement Run completed 16 Working Days after the Settlement Day
UNC	The Uniform Network Code
Winter Contingency Offer	A Bid Offer Acceptance which relates to a Winter Contingency BM Unit and which must be removed from Settlement so that the Offer volume can instead be Settled as Balancing Services Adjustment Data (BSAD) and Applicable Balancing Services Volume Data (ABSVD), in accordance with Approved Modification P447.
Winter Contingency Notification	Details of the data correction required to remove a Winter Contingency Offer from Settlement.
WD	Working Day

Full definitions of the above acronyms are, where appropriate, included in the BSC.

1.6.2 Definitions

Full definitions of the above acronyms are, where appropriate, included in the Balancing and Settlement Code.

2. Not Used

3. Interface and Timetable Information

3.1 Identification and Agreement of Changes to Data (excluding changes arising from Emergency Instructions)

REF	WHEN⁴	ACTION	FROM	TO	INFORMATION REQUIRED	METHOD
3.1.1	No less than 8 WD before SF Run.	Identify that a data correction is required to data submitted to SAA.	BSC Party or NETSO⁵	NETSO	Details of data correction.	E-mail or fax, NETSO Internal reporting.
3.1.2	Within 1 WD of 3.1.1.	Review proposed data correction and determine if data correction request is valid.	NETSO		Proposed data correction.	Internal Process.
3.1.3	Within 2 WD of 3.1.2.	Provide details of proposed data correction and agree action to be taken.	NETSO	BSC Party	Proposed data correction.	Telephone contact with authorised personnel at BSC Party followed by e-mail.
3.1.3a	Within 5 WD of 3.1.2	Provide details of Winter Contingency Notification or SO-Flag correction data	NETSO	SAA BSCCo	Proposed data correction	E-mail.
3.1.4	By 15:00 hrs within 2 WD of 3.1.3.	Agreed Data Correction received by the NETSO. Proceed to Section 3.2.1.	BSC Party	NETSO	Refer to Section 3.2.1.	E-mail.
3.1.5	15:00 hrs within 2 WD of 3.1.3.	No agreement reached on proposed corrections Proceed to BSCP11.	NETSO or BSC Party	BSCCo, NETSO or BSC Party as appropriate.	Refer to BSCP11.	E-mail.

3.2 (a) Corrections of SAA databases for FPN, BOD and RR data)

REF.	WHEN	ACTION	FROM	TO	INFORMATION REQUIRED	METHOD
3.2.1	Following 3.1.4 and 2 WD before SF Run.	Provide SAA with FPN, BOD and/or RR data correction.	NETSO	SAA BSCCo	Receive Request for Data Change (SAA-I033).	E-mail.
3.2.2	Up to 1 WD before SF Run.	Update SAA database and confirm database updates have been implemented.	SAA	BSCCo NETSO	Report Confirmation of Data Change (SAA-I036).	E-mail.
3.2.3	Following 3.1.3a and up to 1WD before SF Run	Update SAA database and confirm database updates have been implemented	SAA	BSCCo NETSO	Report Confirmation of Data Change	E-Mail.

3.2 (b) Corrections of BMRA and SAA databases (for BOA Changes excluding Emergency Instructions)

Changes to BOALF data (excluding those arising from Emergency Instructions) are applied to the BMRA and SAA databases using an automated process as follows:

REF.	WHEN	ACTION	FROM	TO	INFORMATION REQUIRED	METHOD
3.2.4	Following 3.1.4 and 2 WD before SF Run.	Provide BMRA BOA data correction	NETSO	BMRA	Balancing Mechanism Data (BMRA‑I002)	Electronic.
3.2.5	Following 3.2.3.	Provide SAA with BOA data correction	BMRA	SAA	SAA Balancing Mechanism Data (SAA‑I003)	Electronic.

3.3. No longer used

3.4. Corrections to SAA Databases arising from Emergency Instructions

The process is triggered by the issue of an Emergency Instruction by the NETSO.

In accordance with the Grid Code and Section Q5.1.3(b) of the BSC, Emergency Instructions issued in respect of a BM Unit shall be treated as Bid-Offer Acceptances, except certain System Restoration processes, Maximum Generation Service and Emergency De-energisation Instructions⁶.

The NETSO identifies Emergency Instructions as being either:

‘Emergency Acceptances’; or
‘Emergency Flagged’ Acceptances.

BSC Annex T-1 details how Emergency Instructions are treated in the Energy Imbalance Price calculations.

As well as Emergency Instructions, steps 3.4.6 to 3.4.11 may also be used to enter Acceptance Data for Network Gas Supply Emergency Acceptances into SAA databases, in accordance with process steps 3.5.3, 3.5.8 and / or 3.5.13 below.

REF.	WHEN	ACTION	FROM	TO	INFORMATION REQUIRED	METHOD
3.4.1	As soon as possible after issuing Emergency Instruction	Send details of Emergency Acceptance to BMRA and BSCCo.	NETSO	BMRA BSCCo	Receive System Related Data (BMRA-I003) Time of Emergency Instruction Affected BM Unit (s)q	E-mail. . Phone/Fax/E-mail.
3.4.2	Upon receipt of information following 3.4.1	Publish notice on BMRS⁷	BMRA	BMRS Users	Publish System Related Data (BMRA-I005) Time of Emergency Instruction Affected BM Unit (s)	Electronic.
3.4.3	Upon receipt of information following 3.4.1	Log details of Emergency Acceptance and allocate reference number.	BSCCo		Details of Emergency Acceptance. BSC Service Desk reference number.	Internal Process.
3.4.4	As soon as possible after 3.4.3	Provide reference number for Emergency Acceptance.	BSCCo	NETSO	BSC Service Desk reference number.	Phone/Fax/E-mail.
3.4.5	After 3.4.1 and where possible, at least 1 WD prior to II Run⁸	Identify and agree Emergency Instruction related Acceptance with BSCCo and Party.	NETSO	BSCCo Party	Acceptance Data arising from Emergency Instruction	Phone/Fax/E-mail.
		Decide whether it is to be treated as ‘Emergency Flagged’.	NETSO		Decision on whether the Emergency Acceptance is to be treated as ‘Emergency Flagged’.	Internal Process.
3.4.6	After 3.4.5 and where possible at least 1 WD prior to II Run	Send Acceptance Data and details of approach for settling Emergency Instruction to the BMRA, SAA and BSCCo.	NETSO	BMRA SAA BSCCo	Receive System Related Data (BMRA-I003) Receive Request for Data Change (SAA-I033) Acceptance Data arising from Emergency Instruction Specify whether the Emergency Acceptance is to be treated as ‘Emergency Flagged’.	E-mail.. Phone/Fax/E-mail.
3.4.7	Upon receipt of information after 3.4.6	Publish details of Acceptance Data to be entered into Settlement and whether it is to be treated as ‘ Emergency Flagged’⁷	BMRA	BMRS Users	Publish System Related Data (BMRA-I005) Acceptance Data arising from Emergency Instruction	Electronic.
3.4.8	Upon receipt of information after 3.4.6	Acknowledge receipt of Acceptance Data and approach for settling Emergency Instruction.	BSCCo	NETSO	Acknowledgement of receipt	Phone/Fax/E-mail.
3.4.9	Upon receipt of information after 3.4.6	Request authorisation to input post event Acceptance Data in SAA Database.	SAA	BSCCo	Report Recommended Data Change (SAA-I034)	Phone/Fax/E-mail.
3.4.10	As soon as possible after 3.4.9	Authorise input of post event Acceptance Data in SAA Database.	BSCCo	SAA	Receive Instruction for Data Change (SAA-I035) Acceptance Data arising from Emergency Instruction.	Phone/Fax/E-mail.
3.4.11	As soon as possible after 3.4.10 and where possible, prior to II run	Enter post event Acceptance Data into SAA Database and provide confirmation Database has been updated.	SAA	BSCCo NETSO	Acceptance Data arising from Emergency Instruction Report Confirmation of Data Change (SAA-I036).	Internal Process. Phone/Fax/E-mail.

3.5. Network Gas Supply Emergency Acceptances

The process is triggered by the issue of an instruction to the Lead Party of a BM Unit which contains Generating Unit(s) to reduce or discontinue the offtake of gas by a Gas Transporter for the purpose of Load Shedding during Stage 2 or higher of a Network Gas Supply Emergency. In accordance with Section Q5.1.3 of the BSC, such instruction in respect of a BM Unit shall be called a ‘Network Gas Supply Emergency Acceptance’ and shall be treated as a Bid-Offer Acceptance⁹. See Appendix 1 for further details.

REF.	WHEN	ACTION	FROM	TO	INFORMATION REQUIRED	METHOD
3.5.1	Without undue delay after receipt of an instruction to reduce or discontinue the offtake of gas	Inform BSCCo of the instruction.	Lead Party	BSCCo NETSO	Details of instruction including, but not limited to: BM Unit; Start date and time Expected approximate duration Revised capacity (MW)	Phone/Fax/E-mail.
3.5.2	After 3.5.1 and no later than the end of the 2^nd full working day after the Start Date in the instruction	NETSO constructs Acceptance Data relating to the Network Gas Supply Emergency Acceptance. Acceptance Data relating to Network Gas Supply Emergency Acceptances shall always be treated as System Flagged.	NETSO		Information provided in 3.5.1, and other available data e.g. copy of notice or recording of telephone call from Gas Transporter to affected station	Internal Process.
3.5.3	After 3.5.2	Process Settlement Data into Settlement, in accordance with steps 3.4.6 to 3.4.11.
3.5.4	After 3.5.3	Repeat steps 3.5.2 to 3.5.3 as required. A lengthy Network Gas Supply Emergency Acceptance may require data for multiple Bid Offer Acceptance Numbers for each of multiple Settlement Days.
3.5.5	After 3.5.4	Receive notification of the end of the Network Gas Supply Emergency.		Lead Party	Network Gas Supply Restoration Time	Phone/Fax/E-mail.
3.5.6	After 3.5.5	Inform BSCCo and the NETSO of the end of the Network Gas Supply Emergency.	Lead Party	NETSO BSCCo	Network Gas Supply Restoration Time	Phone/Fax/E-mail.
3.5.7	After 3.5.6	Construct final element of Acceptance Data to cover the return to the BM Unit’s FPN (in accordance with submitted Dynamic Data.	NETSO			Internal Process.
3.5.8	After 3.5.7	Submit final element of Network Gas Supply Emergency Acceptance, in accordance with steps 3.4.6 to 3.4.11.
3.5.9	After 3.5.8	Request evidence to demonstrate that Final Physical Notifications and Bid Prices gave rise to Trading Charges consistent with Network Gas Supply Emergency Adjustment Principles	Generation Curtailment Validation Committee	Lead Party Subsidiary Parties	Request for information	Fax/E-mail
3.5.10	After 3.5.9	Provide evidence to demonstrate that Final Physical Notifications and Bid Prices gave rise to Trading Charges consistent with Network Gas Supply Emergency Adjustment Principles	Lead Party and each Subsidiary Party to affected BM Unit(s)	Generation Curtailment Validation Committee	Information required to justify Physical Notifications and Bid Prices (including but not limited to that listed in Section G6.1.2 of the BSC)	Fax/E-mail
3.5.11	After 3.5.10	Generation Curtailment Validation Committee considers evidence and decides whether to direct changes to FPNs, Bid Prices or Acceptance Data			As supplied in 3.5.10	Internal process
3.5.12	After 3.5.11	Provide written details of any agreed changes to data, and the reasons for them	Generation Curtailment Validation Committee	BSCCo Lead Party Subsidiary Parties		Fax/E-mail
3.5.13	After 3.5.12, if changes are required to Acceptance Data	Submit changes to Acceptance Data into Settlement, in accordance with steps 3.4.6 to 3.4.11¹⁰.
3.5.14	After 3.5.12, if changes are required to FPNs and/or Bid Price Data	Submit changes to FPNs and/or Bid Offer Data into Settlement, in accordance with steps in 3.2(a)¹⁰.

4. Appendices

Appendix 1 – Process for Settlement of Network Gas Supply Emergency Acceptances

Approved Modification P448 Alternative introduced a process (described in section 3.5 of this Procedure) by which a Load Shedding instruction issued to a gas-fired generator during Stage 2 or higher of a Network Gas Supply Emergency can be treated as a type of Acceptance (a Network Gas Supply Emergency Acceptance) for purposes of the Code. The intent of this process is to protect the affected generators (and/or their associated Lead Parties and Subsidiary Parties) from the Imbalance Charges they would otherwise have incurred if prevented by the Load Shedding instruction from delivering electricity they had contracted to deliver prior to receipt of that instruction.

The term Network Gas Supply Emergency is defined in the Procedure for Network Gas Supply Emergency issued by National Grid Gas plc. The term does not include Local Gas Supply Emergencies (which therefore fall outside the scope of the NGSEA process), but does include all of the following:

Gas Deficit Emergencies;
GS(M)R Monitor Breaches; and
Critical Transportation Constraints.

This Appendix provides additional information on the roles of the Lead Party (or associated Subsidiary Parties) and the Generation Curtailment Validation Committee in ensuring that these Acceptances are correctly settled. The Appendices use the following acronyms (in addition to those used in the body of the Procedure):

NGSEA	Network Gas Supply Emergency Acceptance
GCVC	Generation Curtailment Validation Committee

What types of BM Unit can use the process?

The process for Settlement of NGSEAs is open both to transmission-connected power stations (registered in a CVA BM Unit) and embedded power stations (registered in a CVA BM Unit or a Supplier BM Unit), provided that the Lead Party and/or associated Subsidiary Parties are able to demonstrate to the GCVC that the affected power stations had a firmly agreed contracted position prior to receipt of the Load Shedding instruction. This is necessary because the intent of P448 Alternative is to protect Lead Parties and Subsidiary Parties from Imbalance Charges only to the extent that they relate to such contracted positions. See below for further details of the criteria that the GCVC is required to take into account when considering whether a contracted position was sufficiently firmly agreed.

Where possible, the NETSO will deem the Acceptance Data relating to an NGSEA. Where the NETSO cannot do this (perhaps because the Lead Party does not submit Physical Notifications for this BM Unit) the GCVC will construct Acceptance Data from scratch. However, the nature of the GCVC process is that this will take longer, and the NGSEA will therefore not be Settled until a later Reconciliation Run.

Overview of Settlement process for NGSEAs

The process for Settlement of NGSEAs is described in section 3.5 of this Procedure, and can be summarised as follows:

1. In the first instance, the NETSO is responsible for constructing Acceptance Data for the NGSEA, which shows the reduction in output (relative to the FPN) arising from the Load Shedding instruction. If the Load Shedding continues for a protracted period of time NETSO may need to construct Acceptance Data for multiple Settlement Days, and multiple Bid Offer Acceptance Numbers per Settlement Day. The NETSO may do this on a rolling basis, creating further Acceptance Data for each day as it becomes certain that Load Shedding has continued into that day. Where possible the NETSO should submit Acceptance Data prior to the Interim Information (II) run for each Settlement Day, but where this is not possible the data may be entered into Initial Settlement (SF) or subsequent Reconciliation Runs.

2.Entering the Acceptance Data into Settlement (in accordance with section 3.5 of this Procedure) will have the effect of ensuring that, in relation to the Accepted Bid Volume (calculated as the difference between the FPN and the Acceptance Data):

The Lead Party and/or associated Subsidiary Parties are not subject to Imbalance Charges; and
The Lead Party must pay the Bid Price (or be paid it, if the price is negative). This payment is intended to reflect the financial benefit to them of not being required to burn the gas and generate the electricity).

3.The intended purpose of these cash flows is to mitigate the risk of generators subject to Load Shedding (and/or their associated Lead Parties and Subsidiary Parties) being exposed to excessive Trading Charges as a result of events outside of their control. They are not intended to allow generators (and/or their associated Lead Parties and Subsidiary Parties) to benefit financially. To provide assurance of this, the GCVC will examine the Settlement Data relating to each NGSEA (and accompanying data provided by the Lead Party and/or Subsidiary Parties), and may amend data (for purposes of Settlement) as follows:

Amend the FPN up or down, to better reflect the contracted position prior to receiving the Load Shedding instruction;
Amend the Bid Price up or down, to better reflect the Avoidable Costs saved by the generator as a direct result of reducing their generation to comply with the Load Shedding instruction;
Amend the Acceptance Data constructed by the NETSO to better reflect the Load Shedding instruction(s) issued to the affected power station(s), and their subsequent return to the level of FPN. For example, the GCVC would need to do this if it had made a reduction to the FPN which had the effect of reducing the Run-Up time required to return to the FPN Final following the end of Load Shedding;
Create FPN Data or Bid Offer Data, where none was submitted under Grid Code processes; and/or
Create Acceptance Data, where the NETSO was not able to do so.
If a Lead Party or Subsidiary Party disagrees with the changes made to Settlement data by the GCVC, they may appeal their decision to the Authority.

Role of the Lead Party and/or Subsidiary Party

When a power station is subject to Load Shedding in Stage 2 or higher of a Network Gas Supply Emergency, the Lead Party of the BM Unit must inform the NETSO and BSCCo without undue delay. If the Lead Party is not directly involved in operation of the power station they may need to ensure that the generator informs them, so that they can inform the NETSO and BSCCo. If there is a delay in providing this notification it may prevent the NETSO from constructing Acceptance Data, and hence prevent or delay the Lead Party (and/or other parties involved) receiving any protection from Imbalance Charges.

During the period of Load Shedding the Lead Party can continue to update Physical Notifications, Bid Offer Data and Dynamic Data in accordance with the provisions of the Grid Code. However, in accordance with those Grid Code provisions, Physical Notifications for the period of Load Shedding should reflect the firm contracted position of the BM Unit prior to receipt of the Load Shedding instruction. In particular:

The Lead Party may submit Physical Notifications (for periods where they have not already done so), but these Physical Notifications must match the firm contracted position prior to receipt of the Load Shedding instruction; and
The Lead Party may increase or reduce the level of existing Physical Notifications, but only to bring them in line with the firm contracted position prior to receipt of the Load Shedding instruction.

It is recognised that the first three Settlement Periods of Load Shedding may have passed Gate Closure when the Load Shedding instruction is received, and the Lead Party will therefore not be able to update Physical Notifications or Bid Prices for these Settlement Periods to reflect the impact of Load Shedding. The GCVC may address this by directing appropriate changes to data in these Settlement Periods.

The Lead Party (and any associated Subsidiary Parties) must also retain (and provide on request) any records that will allow the GCVC to validate their Physical Notifications and Bid Price.

Demonstrating that Physical Notifications reflect a firm contracted position

One of the roles of the GCVC is to verify that the Final Physical Notifications (used to calculate the Accepted Bid Volume) do reflect the BM Unit’s firm contracted position prior to receipt of the Load Shedding instruction. The Lead Party and/or associated Subsidiary Parties are therefore required to provide the GCVC with records demonstrating that, prior to the power station receiving the Load Shedding instruction:

They knew that the power station intended to generate at the level reflected in the BM Unit’s Final Physical Notification; and
This level of generation was reflected in firm power contracts. The P448 Alternative allows the GCVC to treat a power contract as firm if either:

The agreed level of generation was reflected in Energy Contract Volume Notifications (i.e. as a direct result of the power station’s planned generation they either notified the sale of that energy volume, or decided not to notify the purchase of that energy volume); or
The level of generation was agreed between the Lead Party and a Third Party Generator, provided that the agreement (e.g. Power Purchase Agreement) requires the Third Party Generator to pay the Lead Party the System Buy Price in relation to quantities of Active Energy that are not delivered.

With relation to point (i) above, Energy Contract Volume Notifications (and the contracts to which they relate) do not identify a BM Unit, so the Lead Party and/or Subsidiary Party will need to have other evidence demonstrating that they did intend (prior to the Load Shedding instruction) to deliver them using the power station that received the Load Shedding instruction. For example, such evidence could take the form of:

Internal records demonstrating that the decision to enter into the contract was made as a result of that power station notifying its intended level of generation; or
Evidence of the ‘merit order’ in which the party generally despatched the units available to it, demonstrating that the contract in question would have been delivered with the power station subject to Load Shedding.

1 For Settlement Days before the implementation of Approved Modification P217.

2 For Settlement Days on or after the implementation of Approved Modification P217.

3 Unlike other Emergency Instructions received after SF, Network Gas System Emergency Acceptances do not need to be progressed via a Trading Dispute.

4 The relevant BSC Party and NETSO are required to adhere to the timeframes set out above. However, in exceptional circumstances, which shall be determined by the NETSO e.g. where a number of data corrections are issued in close succession, these timeframes may not be practical. Where the NETSO has deemed that exceptional circumstances exist, the NETSO and the SAA shall determine and notify the BSC Party of the alternative process to be used. For the avoidance of doubt, BSC Parties are expected to contact the NETSO as soon as they become aware of any potential issues.

5 The SAA may also notify NETSO of any such errors.

6 For Settlement Periods falling within both a System Restoration Period and a Market Suspension Period, no Emergency Instructions shall be treated as Bid-Offer Acceptances. For Settlement Periods falling within a System Restoration Period but not within a Market Suspension Period, any Emergency Instructions issued under BC2.9.1.2(e) of the Grid Code shall not be treated as a Bid-Offer Acceptances. See BSC Section G3, BSCP201 and Grid Code BC2 for further details.

7 Notice to be published using the BMRS ‘System Warning’ function.

8 In exceptional circumstances, e.g. where a number of Emergency Instructions have been issued in close succession, the II run target may not be met. In such cases, the data shall be entered into Settlement in time for the Initial Settlement Run (SF Run). A Trading Dispute will need to be raised to enter such data into Settlement after the SF Run.

9 A Network Gas Supply Emergency Acceptance will always be a Bid.

10Except the role of NETSO shall be replaced by BSCCo.

BSC Procedures

CONTENTS

BSCP 18: Corrections to Bid-Offer Acceptance Related Data