Understanding MHHS

What is MHHS?

Currently, many electricity bills are based on estimates or average usage patterns. This makes it challenging to understand precisely when and how energy is consumed.

What are half-hourly settlements?

With MHHS, smart, advanced meters will record electricity use every 30 minutes. By using this actual half-hourly data, suppliers can precisely match the electricity they purchase with what their customers use every 30 minutes, reducing reliance on estimates.

Who is involved?

Ofgem decided to introduce MHHS in April 2021 and oversees the programme. Elexon, an independent market expert, is coordinating its implementation. They are working with suppliers, network operators, and industry partners to ensure a smooth transition for all parties.

Why is MHHS being introduced?

Smarter Data Insights: Granular, half-hourly data will enable better forecasting of energy usage and allow suppliers to develop more tailored products and services for future energy needs.

Enhanced Settlement Accuracy: Site-specific reconciliation using actual data will enable faster, more accurate settlement between market participants.

Supporting Renewable Energy & Net Zero: MHHS will enable suppliers to offer time-of-use tariffs to more customers. This helps shift energy consumption to times when renewable generation is high, supporting the transition to a net-zero energy system.

How will MHHS work?

The settlement process ensures suppliers purchase the correct amount of electricity from generators. Currently, there are two types of settlement:

Non Half-Hourly (NHH): Based on estimated usage profiles.

Half-Hourly (HH): Based on actual consumption data from meters.

Because HH settlement relies on real-time data, the performance standards and timelines for data providers are much tighter.

What’s changing with MHHS?

MHHS introduces faster and more accurate settlements, driven by new standards that require more data to be delivered more quickly.

Initial Settlement will occur 5-7 working days after the consumption date (the settlement date), using at least 99% of the actual consumption data.

Final Settlement will be significantly shortened—from approximately 14 months down to just 4 months after the settlement date. By this stage, 100% of actual data is expected to be available.

While these improvements tighten industry data processes, the key benefit for customers is enhanced billing accuracy and transparency. Bills will reflect actual usage rather than estimates, reducing discrepancies. This also improves forecasting and enables suppliers to offer more flexible, tailored pricing options.