Market-wide Half Hourly Settlement (MHHS) is a key enabler of the
flexibility to support the transition to Net Zero. The industry-led
MHHS programme was created to implement the Target Operating Model
(TOM) approved by Ofgem
to deliver a faster, more accurate Settlement process for all
market participants by introducing site-specific reconciliation using
Half Hourly meter readings. The MHHS Programme will contribute to a
more cost-effective electricity system, encouraging more flexible use
of energy and helping consumers lower their bills.
The MHHS Programme objective is to maximise the opportunities
provided by smart metering by developing and implementing an enduring
process for MHHS that delivers benefits for Consumers and enables a
smart, flexible energy system.
MHHS reform will see the electricity industry working together
in a significant move forward in how electricity is used and
accounted for. Ofgem have placed responsibility of the MHHS
Programme on the industry to deliver the programme. Elexon are the
Senior Responsible Owner (SRO) and Implementation Manager (IM) of
the MHHS Programme.
The MHHS Programme website provides all the
information on the background, programme delivery, design and
implementation for MHHS.
The MHHS TOM can be found at the bottom of the Programme Overview page.
Migration to the MHHS TOM and the date from which the new
Settlement timetable will become effective are determined by the MHHS
Programme Plan. Dates are subject to change by the programme and can
be found on the Planning pages of the MHHS programme website.
In order to implement the MHHS TOM, the MHHS Programme has
created, baselined and published a set of end-to-end design
artefacts. Further information can be found on the MHHS Design pages of the MHHS Programme website.
Retail Energy Code (REC) and its stakeholders will play an
integral role in the new MHHS arrangements. The
Retail Energy Code Company (RECCo) is responsible for ensuring
that MHHS requirements that impact the REC and REC Services are
delivered and that the solutions have positive outcomes for Consumers.
RECCo is leading the programme to deliver these activities and is
working with the REC
Code Manager, REC Service Providers and the MHHS Programme to
ensure the required changes are successfully delivered, in accordance
with the MHHS Programme Plan.
More detail can be found on the Our Programmes page on the RECCo website.
The REC has representation throughout the MHHS Programme
governance structure and working groups. RECCo has a seat on the
MHHS Programme Steering Group (PSG) and Level 3 governance groups,
and regularly participate in working groups across design, code
drafting, testing, data, migration and planning workstreams. More
about MHHS Programme governance can be found here.
The implementation of the MHHS TOM will see changes throughout
the REC, including:
- Changes required to REC
Category 1, 2 and 3
- Changes required to the Energy Market Data
Specification, including REC-owned Market Messages and Data
- Changes required to the Electricity Enquiry Service
(EES) and Central Switching Service (CSS)
- Changes required
to REC governance and Code Manager services
Changes to the Retail Energy Code (REC) legal text, that are
required to support MHHS implementation, are being delivered under the
governance of the MHHS Programme alongside the drafting required for
other industry codes. This activity is known as MHHS Code Drafting and
the REC MHHS programme has dedicated expert resource leading the
associated REC drafting. Code Drafting is being developed and
consulted on with industry in tranches, throughout 2023 and 2024.
The Cross Code Advisory Group (CCAG) is the decision-making
body, within MHHS Programme governance, that oversees the
coordination, consultation and agreement of the Code Drafting. The
CCAG is supported by a subgroup – the Code Drafting Working Group
(CDWG). The CDWG is open to all industry stakeholders and is
intended to facilitate discussion on the approach to code drafting.
REC stakeholders are encouraged to attend CDWG meetings to highlight
any specific queries or comments relating to MHHS code changes that
require wider industry discussion.
Where issues are identified through MHHS consultations that do
not relate to the MHHS arrangements, then the REC MHHS team and the
REC Code Manager will work together to ensure this feedback is
collated and considered under REC business as usual activity.
For further information on MHHS Code Drafting activity,
including the Code Drafting plan, go to the Code Governance pages on the MHHS Programme website.
Code documents that are impacted, known as Code Artefacts, are
available on the Code Artefacts pages on the MHHS Programme
website. All documents are available with tracked changes.
Not all the impacts to the REC, and other codes, are specified
within the MHHS design. The application of the MHHS design results,
however, in consequential impacts to the Code that have not been
addressed by the MHHS design. These changes have been developed
outside the MHHS Programme governance. Wherever possible they are
agreed under REC governance in time to be fed into the overall MHHS
Code Drafting. The legal text for these solutions will then be
reviewed, consulted on and approved under the MHHS Programme.
Within the REC, these solutions are being governed under the
MHHS Stakeholder Advisory Group (MSAG). Solutions that have been
agreed can be found under the Solution Documents on the MSAG Committee Page on
the REC Portal.
Where consequential changes have proven particularly complex and
material such that industry consensus could not be appropriately
agreed via the MSAG, these have been progressed through the standard
REC change process to ensure the relevant controls in that process
apply to the solution taken forward.
There are a number of MHHS-related REC Change
Proposals that have been progressed outside the main programme
governance. These are:
Main article: MHHS Qualification
The purpose of MHHS Qualification is to confirm that Parties are
ready to operate under the required industry processes and standards
for the new MHHS arrangements. All REC
Parties wanting to operate in the new market arrangements will
need to qualify through MHHS Qualification.
The REC Code Manager, RECCo and the MHHS Programme are working
together to ensure REC Parties and stakeholders have the best
opportunity to have timely access to information about activities and
decisions relating to the implementation of MHHS.
Weekly updates from the MHHS Programme can be found in their
newsletter The Clock.
REC MHHS activities will be communicated through the normal REC
communications channels, and where appropriate will also be
highlighted in The Clock.
The Code Manager will also look to highlight through REC
communications channels key MHHS-related activities, from the MHHS
Programme and other code bodies, that impact REC stakeholders.
The following are the key contact points in the MHHS Programme:
Contact the REC MHHS Programme team at email@example.com