Implementation Guidance for P350: Introduction of a seasonal Zonal Transmission Losses scheme

The Competition and Markets Authority (CMA) Energy Market Investigation concluded that the absence of locational pricing for transmission losses has an adverse effect on competition.

Therefore, in line with the CMA’s determination, P350 will introduce a Transmission Loss Factor for each TLF Zone (which will align with the existing Grid Supply Point (GSP) Groups) for each BSC Season in order to allocate transmission losses on a geographical basis. The CMA is mandating, through secondary legislation and licence changes, an Implementation Date of 1 April 2018.

Latest updates

To find out ongoing information related to P350 in regards to:

• Approved Estimated Transmission Losses Adjustment (ETLMO) Values
• Publication of Transmission Loss Factors (TLFs) and Associated Data

Transmission Losses Data page.

Updated industry review: Transmission Loss Factor Agent (TLFA) service description

Following production of the TLFs as part of the implementation of P350, Elexon and the TLFA have agreed some amendments to the file formats included in the TLFA Service Description to align it with the actual output files produced by the TLFA. In addition, Elexon has added a short section on issue resolution and has corrected some minor errors in the document.

Circular

• P350 Implementation Circular #5

Past key dates

• 20 Nov 2017 – Industry review of TLFA Service Description starts
• 29 Nov 2017 – Industry review of TLFA Service Description stops
• 11 Dec 2017 – Updated TLFA Service Description presented to ISG for approval
• 22 Dec 2017 – Effective date for TLFA Service Description for P350

The document below was approved by the Imbalance Settlement Group (ISG) on Monday, 11 Dec 2017.

Industry review of draft reference Network Mapping Statement (NMS)

The reference NMS shall be used for the purposes of determining Nodal power flows. On 31 August 2017 Elexon provided a copy of the draft reference NMS to the Panel and each BSC Party. The draft reference NMS has been published on this page along with a supporting guidance note and a list of Nodes provided by the Transmission Company.

On 12 October 2017 the Panel approved the reference NMS for use in TLF calculation by the TLFA.

Past key dates

• 10 Aug 2017 – A proposed reference NMS and methodology presented to Panel
• 31 Aug 2017 – Industry review of draft reference NMS starts
• 14 Sep 2017 – Industry review of draft reference NMS ends
• 14 Sep 2017 – Verbal update to Panel on comments from industry review
• 12 Oct 2017 – Updated draft reference NMS presented to Panel for approval
• 19 Oct 2017 – Approved reference NMS published to the BSC Portal

Industry review of Load Periods (LPs) and Sample Settlement Periods (SSPs) Methodology

On 13 July 2017 the BSC Panel approved the amended methodology to identify LPs and SSPs following industry consultation, together with the actual LPs and SSPs to be used in the determination of Transmission Loss Factors for BSC Year 2018/19 (see Panel paper 268/08 – P350: methodology for Load Periods and Sample Settlement Periods).

In addition, the BSC Panel agreed to delegate ownership of the methodology for defining LPs and SSPs to the Imbalance Settlement Group (ISG).

Circular

• P350 Implementation Circular #3

Past key dates

• 11 May 2017 – Draft LPs and SSPs Methodology presented to Panel
• 15 May 2017 – Industry review of LPs and SSPs Methodology starts
• 31 May 2017 – Industry review of LPs and SSPs Methodology ends
• 13 Jul 2017 – Updated LPs and SSPs Methodology presented to Panel for approval
• 24 Jul 2017 – Approved LPs and SSPs Methodology circulated to industry
• 31 Aug 2017 – Chosen LPs and SSPs published to the BSC Portal

Industry review of new and amended Code Subsidiary Documents (CSDs) and Configurable Items (CIs)

The consultation for the new and amended Code Subsidiary Documents (CSDs) and Configurable Items (CIs) for P350 closed at 17:00 on Friday 21 April 2017. The documents consulted on can be found in the tables below. 

Circular

• P350 Implementation Circular #1

Past key dates

• 04 Apr 2017 – Industry review of new CSDs and amended CIs for P350 starts
• 21 Apr 2017 – Industry review of new CSDs and amended CIs for P350 ends
• 11 May 2017 – New CSDs for P350 presented to Panel for approval
• 12 May 2017 – Effective date for new CSDs
• 23 May 2017 – CIs amended for P350 presented to ISG for approval
• 30 May 2017 – CIs amended for P350 presented to SVG for approval
• 01 Jun 2017 – CIs amended for P350 presented to TDC for approval
• 29 Jun 2017 – Effective date for CIs amended for P350

The documents below were approved by the BSC Panel on Thursday, 11 May 2017.

The documents below were approved by the Imbalance Settlement Group (ISG) on Tuesday, 23 May 2017, and the Supplier Volume Allocation Group (SVG) on Thursday, 11 May 2017.

The documents below were approved by the Imbalance Settlement Group (ISG) on Tuesday, 23 May 2017.

The documents below were approved by the Trading Disputes Committee (TDC) on Thursday, 01 Jun 2017.

Past updates

National Grid raised P350 ‘Introduction of a seasonal Zonal Transmission Losses scheme’ on 4 July 2016. The Draft Modification Report for P350 was presented to the Panel on 9 February 2017, who unanimously recommended that P350 be approved. On 24 March 2017, Ofgem approved P350 for implementation on 1 April 2018.