Annual Demand Ratio report as part of Assurance
The Annual Demand Ratio (ADR) is one of the key indicators provided by Elexon to outline potential over or under-accounting of energy generation or consumption. While the ADR cannot provide specific root causes for potential errors, when leveraged in conjunction with other tools it supports the identification and resolution of specific Settlement errors.
How it relates to you
The ADR is a measure of the variation between the total annual profiled Non Half Hourly (NHH) consumption and the total annual metered NHH consumption, and is calculated per GSP Group. It provides a high-level indication of the overall performance of the NHH Supplier Volume Allocation (SVA) market and identifies any significant under or over-accounting of energy generation or consumption.
The ADR is also a measure of the accuracy of Settlement data at a GSP Group level, hence an ADR value is calculated per GSP Group.
As a Key Performance Indicator (KPI), Elexon measures the values of ADR from the Second Reconciliation (R2) Settlement run or later, to monitor the accuracy of Settlement.
Ultimately, Suppliers (in the Supplier Volume Allocation (SVA) market) and Registrants (in the Central Volume Allocation (CVA) market) are accountable for ensuring that actual metered data used in Settlement is accurate. They also need to ensure that any estimated data is calculated using the best available method in accordance with the Balancing and Settlement Code.
Guidance Note
The ADR Guidance Notes provides an explanation of ADR to a greater depth, including calculation methodologies, potential causes of Settlement errors and Elexon’s process for investigations.
Sources of incorrect data
Possible sources of incorrect data include, but are not limited to:
- Errors in the setup of Metering Systems or Metering System faults that lead to consumption or generation volumes being recorded incorrectly
- Errors in the standing data associated with Metering Systems, meaning that consumption or generation volumes are recorded correctly but processed into Settlement incorrectly or not at all
- Prolonged and / or inaccurate estimation of consumption or generation volumes where metered data is not available
Elexon continually operates a range of Performance Assurance Techniques (PATs) to mitigate the risk of errors in Settlement, and to detect and rectify errors that do occur. However, Elexon is not able to prevent, detect, or rectify every error in Settlement.