Metering Systems accurately record the flow of electricity to (an Import) or from (an Export) a site. Metering System data is used to calculate energy imbalance charges. These charges are applied to BSC Parties who use more or less energy than they have contracted to buy or generate.

How it relates to you

A Metering System is made up of items of Metering Equipment; voltage transformers, current transformers, Meters and Outstations, the wires and connections between each item and connections required to transfer metered data to the outside world (e.g. modems and communication lines).

There are two types of Metering System; those which measure and record electrical energy flow for each half hour for Settlement (Half Hourly Metering Systems) and 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).

Suppliers and generators, Licensed Distribution System Operators, the Transmission System Operator, Interconnector Administrators and Elexon also use Metering System data for other charging purposes, both within and outside the BSC arrangements.

Larger sites, in the Central Volume Allocation market, may have several Meters where it becomes necessary to aggregate the volumes of all the relevant Meters to find the total. Registrants of such Metering Systems create and submit Metering System Aggregation rules.

Half Hourly Metering Systems are subject to Technical Assurance of Metering (TAM) Performance Assurance Technique (PAT). TAM is designed to provide assurance that Metering Equipment complies with obligations outlined in the BSC Code and subsidiary documents.

Metering Dispensations

If you’re the Registrant of a Metering System, you can apply for a Metering Dispensation if (for financial or practical reasons) the associated Metering Equipment will or does not comply with the applicable Code of Practice. Generic Metering Dispensations may be applied to any item of Metering Equipment.

Current and Voltage Transformers

Metering Systems can be comprised of measurement transformers such as Current Transformers and Voltage Transformers. The ratios for these transformers are communicated between Parties via Meter Technical Detail (MTD) data flows. These ratios are instrumental in allowing a meter to record the correct primary energy flow to or from a site.

Accurate measurement of transformer ratios is essential for the commissioning process, which is a series of site tests and checks on Metering Equipment. Licenced Distribution System Operators (LDSOs) and Meter Operator Agents (MOAs) will need the valid list of transformer ratios, which can be found via the page alone.

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.

Useful documents


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