MP085B 'Synchronisation of Smart Meter voltage measurement periods (meters currently installed)'

The expectation of Electricity Network Parties during the development of the smart meter technical specification was that the average RMS voltage readings from smart meters would be measured across a consistent period. For example with the default being for an average to be made across a 30 minute period starting on the hour and again on the half hour. This is not an explicit requirement codified in Smart Metering Equipment Technical Specifications (SMETS) or Great Britain Companion Specification (GBCS).

Without voltage measurements being made in a consistent way, Electricity Network Parties must either:
i) make conservative, less efficient analysis assumptions to account for the lack of data alignment, or
ii) recreate synchronised data by downloading high granularity (for example minute resolution) data and calculating the required data.

Investigations during the Refinement Process found the issue affecting existing installed meters more complex than initially envisaged. This could result in a lengthy lead time for implementation where meter Manufacturers could potentially still produce Devices that do not commence average RMS voltage readings on the hour. Therefore, it has been agreed that there should be two separate solutions to address the issue;
• MP085A – a Technical Specifications document change for meter Manufacturers to ensure newly manufactured Devices commence average RMS Voltage Measurement Period readings on the hour or half past the hour (whichever occurs first); and
• MP085B (this modification) – a solution for meters that are currently installed.

The Proposed Solution is to populate the Maintenance Validity Period (MVP) end dates for pre-ESMETS v5.2 version within the TS Applicability Tables (TSAT). This will mean that pre-ESMETS v5.2 Devices can still be installed as the Installation Validity Period (IVP) will remain undetermined. This will reduce scrappage costs as Suppliers and or their contracted meter installers are likely to have existing stock that is yet to be installed. Once the MVP end date expires, the ESME will have to be updated to ESMETS v5.2 or later.

The Proposed Solution will result in ESME Devices gaining additional functionality compared to their current ESMETS version.

The proposed end date is 2 November 2028 to allow Manufacturers enough time to design and produce ESMETS v5.2 firmware updates and for Suppliers to roll them out across their Devices.