P455 ‘On-Site Aggregation as a method to facilitate Third Party Access’ Report Phase Consultation

This Modification seeks to establish a more cost effective and efficient method for delivering Third Party Access on private networks that include domestic and small business customers. It does so by enabling aggregated meter data from sub meters on private networks to be submitted into Settlement in lieu of data from Settlement meters installed at the Boundary Point.



There were five responses received -four in agreement with the BSC Panel initial recommendation that P455 should be approved.

Original consultation

Who will this impact?

P455 is expected to affect:

  • BSCCo
  • Suppliers
  • Generators
  • Licence Distribution System Operators (LDSOs)
  • Half Hourly Data Collectors (HHDCs)
  • Half Hourly Market Operator Agents (HHMOAs)

What is proposed?

The solution proposes a new ‘On-Site Aggregation’ methodology for facilitating Third Party Access on private networks to which domestic and small business customers are connected. This methodology can be used instead of difference metering, but requires the BSC to allow aggregated meter data from meters installed on private networks relating to customers not opting for third party supply to be submitted into Settlement (in lieu of data from Settlement meters installed at the Boundary Point).

The proposed solution was originally limited to connections under the onsite Aggregation method with metering systems that are sub 100kW capacity. This has since been adjusted to sites where aggregated sub meters that are Import only (i.e. demand loads and not generation loads) are limited to sub100kW, to reflect what was originally intended.

Related information


Click on the X next to any of the icons to replace them with a short-cut link to the page you are currently on or search for a specific page.