P395 ‘Excluding generators from BM Unit Gross Demand and the calculation of EMR Supplier Charges’

Formal title: Excluding generators from BM Unit Gross Demand and the calculation of EMR Supplier Charges

Current Status

Initial Written Assessment
Assessment Procedure
Report Phase
With Authority
Awaiting Implementation


Currently the BM Unit Gross Demand Report attributes to Suppliers electricity they have provided to generators (including storage facilities) operated by Generation Licensees, which falls outside the definition of ‘supply’ in the Electricity Act 1989.

The Department for Business, Energy and Industrial Strategy (BEIS) and Ofgem made clear in their joint Smart Systems and Flexibility Plan (published in July 2017) that the Supplier Obligation is not payable in relation to such imports.

On 8 November 2018 the BSC Panel agreed an interim solution to mitigate the impact of this issue, which was implemented by EMRS in February 2019. But this interim solution is limited in scope, and does not fix the issue in all cases. The BSC Panel recognised that an enduring solution to the issue was appropriate, but would need to be progressed through a BSC Modification (once Ofgem had concluded their consultation on ‘Clarifying the regulatory framework for electricity storage’).

P395 proposes to amend BSC systems and processes so that the SAA-I042 ‘BM Unit Gross Demand Report’ only includes electricity ‘supplied’ to premises by licensed Suppliers, and therefore excludes electricity imported by Generators operated by a licensee for generation activities (i.e. those activities authorised by their generation licence to carry on).

To facilitate this outcome, P395 proposes that the BSC incorporates the interim solution and extends it to cover complex sites too. This solution would cover sites connected to both the distribution and transmission systems, and where the sites Metering Systems are registered in Supplier Meter Registration Service (SMRS) or Central Meter Registration Service (CMRS).

Workgroup assessment of the methodology for calculating Imports to Licensed Generation will be required, however the P395 Proposer recommends adopting elements of the solutions for BSC Modifications P344 ‘Project TERRE’, P375 ‘Metering behind the Boundary Point’  and P383 ’Enhanced reporting of demand data to the NETSO to facilitate CUSC Modifications CMP280 and CMP281’. At a high level, P395 aims to adopt or use:

  • Processes introduced by P344 that enable SVAA to request metered data for relevant Boundary Point Metering Systems from HHDAs;
  • Processes being developed by P375 for collecting and processing data from Asset metering by enabling SVAA to request and receive metered data for Asset Meters from HHDCs; and
  • Processes for declaring and validating generator sites and metering systems proposed by P383 – except that this proposal would extend the P383 processes to apply to Asset Metering Systems as well as Boundary Point Metering Systems, and would apply to all Generation operated by a generation licence holder (not just Storage).

If you would like to join the P395 Workgroup, attend as a non-voting attendee, or be added to the P395 distribution, please let us know by emailing bsc.change@elexon.co.uk


Centrica raised P395 on 7 November 2019. The Panel considered the IWA on 14 November 2019 and agreed to advance the Modification to the Assessment Procedure. 

Next Events

The first meeting of the P395 Workgroup took place on Wednesday 19 February 2020 at ELEXON's offices. We are progressing actions taken from this meeting while ascertaining the best time for the next meeting.


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