Metering Systems accurately record the flow of electricity to (an Import) or from (an Export) a site. ELEXON uses Metering System data 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.
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.
What is a Metering System?
A Metering System is made up of items of Metering Equipment: voltage transformers, current transformers, Meters and Outstations, alarms, the wires and connections between each item and connections required to transfer Metering System 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).
Codes of Practice
Codes of Practice (CoPs) detail the technical requirements for Metering Systems. These versions are not time limited in the same way as other documents. When Metering Equipment is first registered in Settlement, it must comply with the requirements which are set out in the relevant Code of Practice in place at that time.