P344 Implementation Guidance: Project TERRE and Wider Access

This page sets out the implementation guidance related to Project TERRE and Wider Access. It explains how these two developments relate to each other and the market will become international in scope and barriers to new types of market participants will be removed.

Delivery approach

We will deliver TERRE and GB Wider Access in two stages:

Stage 1 – February 2019 BSC Release

  • Amended BSC Sections and new or amended BSC Configurable Items, which define the new processes for pre go-live TERRE activities, will become effective
  • Changes to the Central Registration Agent (CRA) and Energy Contract Volume Allocation Agent (ECVAA) software to allow VLPs to accede to the BSC and allow BSC Parties and VLPs to register SBMUs

Further information is available from the February 2019 BSC Release web page.

Stage 2 – Q4 2019

GB TERRE Go Live Date will be determined by ELEXON and the ESO:

  • Changes to the Settlement Administration Agent (SAA), Balancing Mechanism Report Agent (BMRA), Funds Administration Agent (FAA), Energy Contract Volume Allocation Agent (ECVAA) and ELEXON Portal software to give full effect to the TERRE arrangements
  • Changes to the Supplier Volume Allocation Agent (SVAA) software to allow the creation and maintenance of a register to record the MSID Pair allocations to Additional and Secondary BM Units for the purposes providing Balancing Services
  • Changes to the Interface Definition and Design (IDD) spreadsheets and other BSC Configurable Items relating to the Stage 2 software changes will be issued separately for review in 2019 on this page
  • A parallel running test phase is expected to commence in August 2019 that is intended to be a full end-to-end test of all systems and processes. This will be followed by TERRE go-live between October and December 2019

TERRE interface designs

On 16 January 2019 ELEXON shared early drafts of Interface Definition and Design documents (IDDs) to support the GB Electricity Industry with their preparations for P344. ELEXON has prioritised the interface design based on industry demand.

The early draft interface definitions that were shared are the SAA-I014 settlement reports (Subflows 1-3), which have been documented in the ‘NETA Interface Definition and Design’ (IDD) spreadsheets.

Please note that approved P344 changes for the February 2019 BSC Release have been included.

ELEXON has made every effort to ensure the drafts are as close to the final versions as possible but they will remain subject to change whilst the ENTSO-e TERRE Implementation Guide is still in draft.

There is a risk that the requirements could change, but it has been necessary for ELEXON to start work on TERRE in order to be ready for the parallel running.

Colour Coding Guidance

The IDD documents have been colour coded to assist with readability:

  • Blue tabs – Indicate worksheets that have been impacted by P344
  • Blue text – indicates fields that have been impacted by P344
  • Red text – Indicates fields that have changed since the previous draft
  • Orange text – Indicates fields that have changed since draft C

  • Orange tab – Indicate worksheets that have been amended since draft C

Please note that Draft A of the IDDs was not published but shared with the ESO and Electricity Market Reform program directly for initial feedback.

Comments and Feedback

Any suggestions to improve readability or priorities for other external interface designs are welcomed. Please direct questions, comments and feedback to releases@elexon.co.uk.

Replacement Reserve Schedule Methodology

Section T1.14 of the Balancing and Settlement Code (BSC) requires the BSC Panel to establish (and subsequently have in force) a Replacement Reserve (RR) Schedule Methodology Document.

The BSC requires that this document contains detailed requirements for BSC Settlement processes to deem Acceptance Volume Pairs representing the instructions that the National Electricity Transmission System Operator (NETSO) would need to issue to a BM Unit in order to instruct it to deliver the results of each Replacement Reserve Auction.

The primary purpose of the RR Schedule is to define the volume of energy that a BM Unit must deliver in each Settlement Period, in order to be treated in Settlement as having fully delivered its RR Activations.

Where a BM Unit does not deliver this volume of energy, its Lead Party may be liable to Energy Imbalance Charges and Non-Delivery Charges.

Consultation on Replacement Reserve Schedule Methodology

On 16 January 2019, ELEXON invited the Transmission Company and BSC Parties to review the proposed methodology and return any comments to ELEXON.

Please send comments by 17:00 on Wednesday 30th January 2019 using the response form provided.


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