Webinar round-up: Countdown to Market-Wide Half-Hourly Settlement

July 23, 2024

On July 18th, 2024, we hosted a webinar for all REC Parties to explain the significant changes that Market-Wide Half Hourly Settlement will bring to REC arrangements. The webinar also covered the tasks REC Parties must complete over the next nine months to ensure REC compliance at MHHS go-live. We want to extend our gratitude to everyone who attended the event – the materials are now available below, alongside another opportunity to provide your feedback. If you missed it, you can access a summary, presentation slides, webinar recording, and Q&A below.

Webinar summary

Compulsory changes will be required by REC Parties operating in the electricity market at MHHS go-live, regardless of their planned qualification wave. It is crucial for impacted REC Parties to be ready for these changes and include them in their implementation plans.

Experts from RECCo and the Code Manager discussed the following key topics:

Changes to REC-owned data flows
The impact on CSS Switching arrangements
REC Change Proposal R0083, which details changes to the Supply Number format
The introduction of a table detailing metering configuration domain data
The changes being made to support forward/reverse migration
REC Performance Assurance and MHHS
Changes being made to the Electricity Enquiry Service

Watch the recording

Watch the recording below or download the presentation slides here if you missed the webinar.

Answering your questions

During the webinar, we received many questions. Below are our responses grouped into topic areas.

Topic: General

1. How will MHHS affect MOP/DC contracting for TPIs?

There are no expected direct impacts on MOP/DC contracting. However, if suppliers plan to operate in the MHHS market, they will need to qualify for MHHS roles. Suppliers’ obligation to manage agent appointments remains unchanged. The MHHS Programme is overseeing the completion date, and there are currently no proposed amendments to this. We are proceeding with the assumption that the go-live will take place as planned.

2. With the volume of meters that need migrating, are there physically enough engineers in the UK to meet the target?

The MHHS design does not require a physical site visit or meter exchange to migrate metering points to MHHS.

Topic: DTN changes

1. Are there any plans to amend the D0002 flow to include J codes?

The D0002 is a BSC-owned flow and, therefore, not captured within the REC slides. No structural changes to the D0002 are anticipated for MHHS. New Scenario Variants will be required to enable the flow to be sent to and from MHHS agents.

2. Will the MHHS DTC go-live on 07/03/2025 impact or replace the Feb 2025 Industry Release go-live that would normally occur one week before that?

The February 2025 release will take place as normal, noting the change freeze that is currently in place for MHHS. We are not currently anticipating any DTC flow changes to be included in the February 25 release. However, if changes are included we would expect them to mainly cover non-MHHS changes (gas, etc.) or MHHS-enabling changes.

Topic: Supply Number Format Changes (R0083)

1. Why is Profile Class (PC) being retained?

Profile classes 02 and 04 are being retained in the MHHS design so they can be used by the BSC’s Load Shaping Service to identify ‘Non-Smart Switched Load’ and assign MPANs to the relevant Load Shape Category. The PC is being retained in the Supply Number format for continued use by parties to identify traditional meters. This will also enable continued use of the PC throughout the transition for those MPANs that have not yet been migrated.

2. If other parties use the full MPAN details, is this change mandated, or does this only apply to Suppliers?

The provision of the Supply Number on bills and/or annual statements is a license condition for all Suppliers. The format of the Supply Number is prescribed in the REC. It is that format that is being changed under R0083 and is mandatory for all Suppliers.

For the purposes of maintaining data within the industry, the Supplier is responsible for populating the Profile Class / Standard Settlement Configuration (SSC) in the Registration Service where applicable. The Profile Class is only relevant for traditional meters. The SSC is mandatory for traditional meters and optional for smart meters. If the Energy Supplier chooses not to populate the SSC for non-traditional meters. We are considering creating guidance on when the SSC should be populated for Smart meters.

3. Will there be a mapping of DUoS IDs to LLFC IDs?

This will be maintained by Elexon.

4. Will there be clarification and examples of what the MPAN topline will provide for migrated MPANS for non-MHHS-ready suppliers for the purposes of pricing and forecasting?

The MHHS topline will provide the PC, SSC, and LLF/DUoS Tariff. Note that the PC and SSC are only mandatory for traditional meters. The existing MTC data item will continue to be provided for MPANs before MHHS migration but is not an MHHS data item.

Example toplines are provided in the Data Specification legal text.

Topic: Meter Configuration Table

1. I understand the SSCs and TPRs will be held in ISD. Will the Meter Config Table be a duplicate resource?

SSCs and TPR tables are not being migrated to ISD from MDD. They will remain static within MDD to be used for legacy MPANs, but the tables held on the REC Portal will be the single version of the truth for MHHS MPANs. Any future changes to the valid set of SSCs or TPRs can only be made to the tables held in the REC.

2. Will PC/SSC be retained after MHHS go-live to support legacy activity?

The MDD tables will be frozen and maintained by Elexon as long as required for legacy activity. (Note: all MPANs are expected to have migrated to MHHS by October 2026). The Meter Configuration Tables maintained on the REC Portal will be the enduring solution for MHHS MPANs.

3. How do we identify MTC?

The MTC is not being retained for MHHS-migrated MPANs and will have no further use.

4. Is there a consultation live on the meter config tables?

Yes, the consultation for the Category 3 Change Proposal, C3-0089 Meter Config Table is live on the REC Portal here.

Comments are requested by 27/07/2024.

Topic: Switching exceptions and switch meter reads

1. Are the exception processes applicable to non-migrated MPANs or only migrated?

The changes apply to MHHS Migrated Metering Points only. The code drafting differentiates between the provisions applicable to MHHS and Non-MHHS Metering Points. Here is a link showing the redlined changes in the latest version of Schedule 30.

2. How is settlement volume going to be reallocated between parties if we cannot replace the read in settlement?

Suppliers can issue the amended meter reads to the data service to be reflected in settlements pre-RF. Post-RF, the only way to correct data would be via a trading dispute under the BSC. However, materiality thresholds apply to trading disputes. From a REC perspective, the provisions are clear that erroneous data should be corrected within Consumer bills even if the data cannot be corrected in settlements.

Topic: Forward and Reverse Migration

1. Where SMRS have sent the D0170 will the new MHHS agent have sight of who the old agent was?

Under the MHHS Design, the Gaining Supplier Agents are only informed of the identity of the Losing Supplier Agents during the BAU MHHS appointment process. The identity of legacy Supplier Agents is not included in the appointment request (IF033) for forward migration. If the Gaining MOA does not receive MTDs as expected, then they may need to contact the Supplier to enable them to identify the Losing MOA and request the MTDs themselves.

2. Is there a list of which suppliers will be MHHS compatible from the start date?

Details of MHHS Qualified Suppliers, DNOs and MOAs will be available within the REC Party Register.

3. The main question for our customers is: If they have signed a 5-year contract with a specific MOP provider for MOP services and a 5-year deal with a specific DC provider for Data Collector, will the Appointed MOP and appointed DC be able to object to any different MOP and/or DC appointing themselves? In the same way a new supplier can be objected to, is this now going to be possible for MOPs and DCs (particularly DCs)?

In response to the specific question, there is nothing in the MHHS design that allows losing agents to object to de-appointment. Suppliers and Supplier Agents with concerns regarding the approach to managing migration of metering points where the customer has directly appointed their agents should raise this through the MHHS Programme or directly with Ofgem. From a REC perspective, the Supplier is responsible for appointing the MOA and should be discussing any issues regarding customer-appointed agents with the relevant agent or the customer themselves. Concerns regarding Data Collector appointment should be raised under BSC governance.

Topic: Legacy Change Assurance

1. Is the declaration for SIT and non-SIT parties?

The declaration is required for all REC Parties (including those participating in SIT). Even for some SIT Parties (e.g., non-MVC), there might be a small period between the MHHS cut-over and when they complete the MHHS Qualification.

2. If we make that declaration, we can make it regarding progress on the program. However, what about other changes, such as 4G communications or background systemic changes? For example, a new billing engine could materially impact our timelines and resources.

The scope of this activity is around the consequential changes to the REC in preparation for the MHHS cut-over. Therefore, the specific areas noted in this question aren’t expected to be in the scope of this assurance activity but may be relevant if you feel they may impact your ability to meet any of your REC obligations. If anyone has any questions about whether their proposed changes are within the scope of this legacy assurance activity or whether they will require disclosure to the REC, please contact the Service Desk or your OAM, who will facilitate a conversation with the relevant members of the Code Manager.

Topic: REC Data cleanse – interactions with the MHHS programme

1. Is there an escalation process for data cleanse activity?

As stated in the Data Cleanse—Report Guidance, data cleanse sprints have targets set that are approved by the PAB. Performance Assurance Techniques (PATs), as approved by the PAB, are applied as an escalation process when Parties do not meet their targets. All Parties have the opportunity to attend the REC Issues Group (RIG) to discuss the challenges they are facing and share their experience in resolving data cleanse issues.

2. When will the REC change be raised?

The Category 2 change to the Performance Assurance Reporting Catalogue (PARC) will be raised in August to enable an impact assessment from Parties in September 2024.

Topic: EES Changes (GUI and API)

1. Have C&C confirmed that they are adding the new MHHS fields to the commercial SUDS extract?

C&C have confirmed they will discuss bespoke reports directly with affected Parties. As SUDS reporting is a commercial agreement between C&C and the requesting party, it’s difficult for us to comment. Please raise any queries in this area directly with C&C.

2. How often will the Annual Consumption be updated? Will it be available for all MPANs from 7/3/25?

The Elexon Market Data Service will update the Annual Consumption monthly. This is an MHHS process, so only MHHS-migrated MPANs will display this item.

3. Will we be able to see Associated MPANs?

Yes, MHHS doesn’t change this. These are currently available in the EES API and Portal.

4. When can non-SIT participants test the EES updates?

A test version will be made available from 30th October, in parallel with MHHS UIT.

5. When will the removed data items be going?

An exercise to remove legacy data items and flows is anticipated following M15.

6. Will the Annual Consumption be available on day 1 of migration to MHHS? If so, what will it be based on? Will it just be based on the existing EAC?

The process for calculating the AC is detailed in the Annual Consumption Method Statement held on the MHHS website, but it will be based on what data is available at that time. It is unlikely that an AC will be provided on the first day of migration.

7. Can we test the API anytime after Oct 24, or can we only test it during our Qualification Wave?

The API changes affect all Parties from March 25 regardless of MHHS qualification, so access to the test environment is not dependent on MHHS qualification or tied to waves. To confirm, the MHHS test version of the API will be open to all API users from October.

8. Is there a way to view legacy data items for MHHS-migrated MPANs?

Unfortunately, this is not part of the EES design. On a reverse migration, Smart / Advanced MPANs are not required to return to their previous configuration. Note that SMRS will return the previous items on the D0217/D0260.

9. Will the AC be available for non-legacy meters, too?

The Annual Consumption will be available for all Metering Points that have been MHHS migrated at some point. (Trad, Smart and Advanced) It will not be available for MPANs that have not yet migrated.

10. Based on EES API Interface Specification section 2.1.2, where data items for legacy are still available during the transition stage, is this only for UI or API?

The EES API Interface Specification applies to the API only. Where legacy data items are absent in MHHS, the API will return them as null. In addition, where data items such as the SSC have not been populated by the Supplier, they will be returned as null.
The EES Portal will have different screens depending on an MPAN’s migration status. A migrated MPAN will not display legacy-only data items, and a legacy will not display MHHS data items.

11. Before migration, what is the last date by which old ECOES data can be retrieved?

The legacy information will be available until an MPAN migrates. EES will receive the migration information between 20:00 and 21:00 the day before the migration goes live.

12. Is it possible to retrieve from ECOES data (EES) for Profile Class (PC) and Meter Timeswitch Code (MTC)?

EES will continue to hold the PC and MTC for non-migrated MPANs. Following Migration, the MTC is no longer a valid item and is not retained, and the PC will continue to be held where populated. Note that this is only mandatory for traditional meters.