MHHS Risks: Data Gaps, Supplier Errors, and Budget Surprises
The Market-wide Half-Hourly Settlement (MHHS) programme promises fairness and accuracy. But between rollout delays, metering challenges, and supplier missteps, the risk of costly surprises is high. Here’s what business leaders need to watch for.
MHHS will transform billing by aligning costs with real half-hourly usage. But precision brings complexity. For businesses managing multiple sites, new contracts, and stretched budgets, even small errors in data or settlement can cascade into significant overspend. Understanding where those risks arise, and how to mitigate them, is the first step to avoiding margin erosion.
Risk 1: Data gaps from incomplete metering
MHHS depends on every meter producing half-hourly consumption data. But not all meters are ready. Some sites still rely on older models, some transmit irregularly, and some portfolios include a mix of meter types.
- Missing intervals: If data isn’t captured for certain hours, suppliers may “estimate” often in ways that inflate charges.
- Communication failures: Sites with poor signal (e.g. basements, remote areas) risk frequent gaps.
- Meter replacement delays: If upgrades fall behind schedule, sites may be stuck in limbo billing.
Mitigation: Audit your meter estate now. Confirm every site is MHHS-ready, and create a tracker for upgrades. Data gaps caught early are far easier to correct.
Risk 2: Supplier system errors
Suppliers are under pressure to adapt billing systems, and history shows teething problems. When data is processed at half-hourly granularity, the chance for mismatches multiplies.
- Incorrect settlement rates: Applying the wrong wholesale price to a period.
- Duplicate intervals: Charging twice for the same 30-minute slot.
- Profile misallocation: Assigning your site to the wrong load category.
Mitigation: Implement invoice validation. Line-by-line checks against expected consumption and published settlement prices catch errors before payment. This is where finance and facilities alignment is critical.
Risk 3: Budget shocks from volatility
Even with perfect data, MHHS creates volatility. Energy costs now reflect wholesale market swings and peak-time behaviour. A budget based on averages will be shredded by half-hourly exposure.
- End-of-month surprises: Bills arrive higher than forecast due to peak load.
- Board-level tension: Finance teams forced to explain unplanned overspend.
- Margin leakage: High energy costs quietly reduce profitability.
Mitigation: Transition from static budgets to dynamic forecasting. Use half-hourly data to model future exposure. Better still, align procurement contracts with your actual load profile.
Risk 4: Portfolio complexity
Many businesses operate multiple sites, each with unique consumption patterns. Under MHHS, the complexity compounds:
- Uncoordinated upgrades: Some sites half-hourly ready, others not.
- Inconsistent data feeds: Different meters and suppliers mean patchwork reporting.
- Administrative overhead: Finance teams drowning in raw interval data.
Mitigation: Centralise data capture. A single platform can consolidate half-hourly usage across your portfolio, turning chaos into clarity.
Risk 5: Regulatory uncertainty
MHHS is still evolving. Timelines shift, technical specs change, and regulators issue updates. Businesses relying on outdated assumptions risk procurement missteps.
Mitigation: Monitor Ofgem announcements and industry updates closely. Or better, work with a partner whose role is to stay ahead of the regulatory curve.
Practical steps to manage MHHS risk
The risks are real, but not unmanageable. Finance directors and facilities managers should prioritise three actions:
- Establish validation processes: Don’t assume invoices are correct. Build checks into your workflow.
- Invest in visibility: Ensure you can see half-hourly usage across your estate.
- Align contracts: Procurement should anticipate half-hourly settlement, not be blindsided by it.
What happens if you ignore the risks?
The danger is not that MHHS fails, it will roll out. The danger is assuming your supplier “has it covered” while unnoticed errors accumulate. By the time finance spots an overspend, contracts are locked, budgets are set, and margins are already eroded.
The choice is clear: do nothing and absorb hidden costs, or act now to validate, monitor, and control.
Final thought: risk or opportunity?
Every systemic change creates winners and losers. MHHS will reward businesses that treat risk management as a strategic lever. By tightening data, auditing invoices, and aligning procurement, you can turn potential shocks into competitive advantage. But the window to act is before rollout completes, not after.
What’s next?
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