Erroneous Large EACs and AAs
The Estimated Annual Consumption (EAC) is the forward looking estimate based on an average of previous AAs. However, Large Estimated Annual Consumption is something that Elexon will want clarification on to ensure that it is either accurate or inaccurate. If it is inaccurate we refer to this as Erroneous Large EACs and we will want to understand more about why this is appearing in the data.
On this page
How it relates to you
Erroneous Large EACs (Estimated Annual Consumption) and Annualised Advance (AAs) can significantly affect Suppliers.
At a market level, error is absorbed through the application of Group Correction Factor. However, the issue affects Suppliers through the misallocation of the error during Supplier Volume Allocation. Erroneous Large EACs and AAs also distort a Supplier’s share of market-level consumption.
Suppliers pay for any resulting erroneous electricity consumption and face additional cost through higher Distribution Use of System (DUoS) and Transmission Network Use of System (TNUoS) charges.
ELEXON monitors Large EAC/AAs and provides reporting to the Performance Assurance Board (PAB), the Trading Disputes Committee (TDC) and the industry.
The Large EAC/AA system uses data collected from Non Half Hourly Data Aggregators (NHHDAs), Suppliers and Non Half Hourly Data Collectors (NHHDCs). Data is collected monthly before running the system.
The primary information is obtained from NHHDA databases. Each NHHDA, using a standard script, provides us with details of all consumption values above the agreed Large EAC/AA thresholds.
This information is provided each month and processed by the Large EAC/AA system. The system compiles a complete list of the instances of excessive consumption that currently exist in NHHDA.
From the reports the system produces, Suppliers can notify us of consumption values they believe are genuine.
The Supplier/NHHDC can notify us that a specific value (EAC or AA) is correct and provide a reason why that Metering System genuinely consumes over the threshold.
Instances of genuine high consumption confirmed by the relevant Supplier are removed from materiality calculations.
Large EAC AA production process
The Large EAC/AA system uses data collected from Non Half Hourly Data Aggregators (NHHDAs), Suppliers and Non Half Hourly Data Collectors (NHHDCs).
The primary information is obtained from NHHDA databases. Each NHHDA, using a standard script, provides Elexon with details of all consumption values above the agreed Large EAC/AA thresholds.
This information is provided each month and processed by the Large EAC/AA system. This is because the process compares the files sent in by NHHDA’s to yours. The system compiles a complete list of the instances of excessive consumption that currently exist in NHHDA.
- Guidance Note on The Management and Resolution of Erroneous Large EACs and AAs
- Training Video on Managing Erroneous EACs and AAs
- Contact your OSM if you have questions after watching the training videos.
- BSC Signatories and Qualified Persons page lists companies who have OSMs assigned to them.
To run the Large EAC AA process all NHHDA’s must submit their files on time.
Late submissions will not be included and a previous file will be used, which may lead to incorrect instances being included within a suppliers Instance Reports.
The large EAC AA process cannot run without all of the NHHDA data.
For the most accurate report, suppliers must ensure that they submit the supplier confirmed file by the deadline.
If not, no file will be used for the particularly supplier, which may prevent you from correcting your instances.
Late submissions will not be included.
Supplier File Format
The correct file format is a .csv file only, with no password.
For help with creating your Supplier Confirmed files please use your Materiality Calculator.
For any additional assistance, please contact your Operational Support Manager (OSM).
NHHDA File Format
The correct file format is a .txt or .out files only, with no password.
Deadline for file submission
Operation Support Managers will chase late submissions and may refer companies to the Performance Assurance Board (PAB) if data is not made available. Delays to reports may also occur if NHHDA inputs are frequently late.
Delays to reports may occur if there are too few supplier confirmed files for the system to run.
Large EAC AA Calendar (Size: 230.63 KB)
Submitting ABU Data
Each month when you receive your Erroneously Large EAC/AA Instance Report, you should also receive a copy of the EAC/AA Material Calculator, along with an FAQ explaining how to use the calculator.
The EAC/AA Materiality Calculator can be used to create a file containing ABU data for submission to ELEXON.
Files should be emailed to [email protected].
Accessing your data reports
Elexon will generate and send you the following data reports:
- Instance Report
- Materiality Report
If you have not received your report or have forgotten your password please contact your Operational Support Manager.
Possible errors in data reports
Elexon create the reports from NHHDA data. If you believe there is an error in a report, please speak with your NHHDA to have this amended.
Please note that these sheets are macro enabled.
Issues arising from SOLR
PAB216/11 states that regarding trading disputes; ‘Settlement Dates falling before the SoLR Appointment Day will be the responsibility of the failing Supplier to correct.
However, this is not likely if the company has ceased trading, therefore the new supplier has inherited an issue it is unable to resolve. Therefore, during a SoLR, MPANS and their corresponding instances in the Large EAC/AA system transfer over to the new supplier.
The monthly instance reports sent out to suppliers includes all instances for settlement dates up to the RF date, irrespective of the SoLR appointment date. The Large EACAA system cannot separate inherited instances from the total portfolio of the new supplier.
If you are in this situation, please contact us at [email protected] and let us know.
Contacts from previous Suppliers
If you have difficulty finding the right contact when trying to resolve an erroneous large EAC/AA affected by a Change of Supplier issue Elexon is able to supply a list of contacts, which may be of assistance to you.
This is made available on a monthly basis.
If you would like to be added to the distribution list, please email [email protected].
Please note, to receive a copy of this list you will need to provide the contact details of someone at your organisation who can act as a first point of contact for erroneously large EAC/AA Change of Supplier issues, for inclusion on this list.
Correcting Erroneous Large EACs and AAs
Please investigate any Large EAC/AA instances that are confirmed to be erroneous and take corrective actions where necessary.
Erroneous Large EAC/AA instances should be corrected before the RF run if possible.
Column S of the instance report indicates the number of days before the RF run takes effect. Please prioritise the resolution of erroneous Large EAC/AA instances that are approaching the RF run.
Please also be aware of the RF boundary when taking any corrective actions, and ensure that crystallised data is not changed post-RF.
Correcting crystallised data
If you need to correct crystallised data post-RF, please raise a Trading Dispute. This is initiated by completing the BSCP11/01 Form
The form must be signed by a Category O authorised person. A Trading Dispute must be approved before crystallised data can be changed post-RF.
Please note that amending crystallised data without an approved Trading Dispute may lead to financial penalties.
Please send the completed form to the Trading Disputes team [email protected].