ESG Supports Supplier E in Going Live with MHHS

Market-wide Half-Hourly Settlement (MHHS) is reshaping the UK retail energy market measures, settles, and innovates, and ESG has been supporting leading suppliers through this transition. Most recently, we worked with E to deliver MHHS capabilities across both Supplier and Meter Data Retrieval (MDR) roles.

From Design to Go-Live

After four years of design, solution build, and System Integration Testing (SIT), ESG supported E to go live in the Supplier role on 26th January. Within two weeks, associated metering go-lives were delivered as planned, marking the move from programme delivery into steady-state MHHS operations.

We supported both Supplier and MDR roles, ensuring data capture, validation, estimation, and aggregation aligned with central service expectations. Our aim was a resilient operating model from day one, enabling controlled MHHS migrations.

Collaborative SIT That Scales

Working closely with E, we aligned SIT scenarios, evidence capture, and governance to programme baselines. This reduced duplication, focused effort on unique risks, and created a framework that we now apply to other clients, accelerating their qualification processes without compromising assurance.

Operational Readiness

Technical systems alone aren’t enough to meet the increased demands of MHHS. We delivered on-site workshops to embed knowledge, refine processes, and prepare operational teams. Training covered the operational runbook, exception management, performance monitoring, and incident response, tailored to market roles and organisational structures.

Cutover & Early-Life Support

Structured rehearsals, clear go/no-go criteria, and defined fallback plans ensured a controlled transition. Early-life support provided hands-on assistance during the first settlement cycles, combining live monitoring with rapid triage of any anomalies. This safeguarded E’s portfolios while enabling a smooth start to MHHS migrations.

E’s full MHHS capabilities are now live, supported by proven processes across Supplier and MDR roles:

• Full MHHS capabilities live across Supplier and MDR roles.
• Faster, more accurate settlement processes.
• Clearer visibility of customer consumption patterns.
• Scalable processes that reduce effort for future client qualifications.
• A framework combining technical compliance with operational confidence.

With full MHHS capabilities now live, E has transitioned smoothly into steady-state operations. The processes, testing, and training established during delivery provide a clear framework for ongoing migrations and day-to-day settlement operations.

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