Why you should care about the Market-wide Half Hourly Settlement
You’ve probably read a lot about MHHS in the last few months, and with good reason. It’s a fundamental change to the settlement processes that underpin the electricity industry. However, for many customers, most of the action and change is occurring behind the scenes. It’s suppliers and their agents altering processes and systems, or dealing with new data flows, as Ofgem has mandated.
The tip of the iceberg
Even so, there are a few changes you’ll get to witness (or may have already noticed) as part of the transition. For example, the top line of your meter number (the Meter Point Administration Number, or MPAN) changed in September 2025 to fit with the new systems. Also, opting to upgrade from a traditional non-half hourly (NHH) meter to a smart/AMR meter – see our article explaining why you should – may require an engineer to visit your business. In addition, you may notice some of your costs changing slightly, as existing agent fees are updated and new ones introduced.
There’ll be some name changes too. The terms ‘Meter Operator (MOP)’, ‘Data Collector (DC)’, and ‘Data Aggregator (DA)’ will transform. Depending on the meter type, ‘Advanced Data Service (ADS)’, ‘Smart Meter Data Service (SDS)’ and ‘Meter Data Retriever (MDR)’ will become the norm. And, following the implementation of MHHS, every user’s consumption will be settled within 4 months rather than the current 14 months.
The MHHS transition may cause some customers to worry – and that’s understandable: change can be difficult. But at Drax Energy Solutions, we’re hoping to alleviate concerns by keeping on top of developments and being clear in our communications. Our internal working group includes a wide range of stakeholders from across the business, and we’re driving forward these changes. We’re also letting you know about the programme, next steps, and likely timelines – and have a ‘Top 10’ of FAQs on our dedicated webpage. In short, you’re in good hands.
Should you ignore MHHS?
No – pretending it’s not happening won’t help you. But being proactive and embracing the change could deliver advantages.
MHHS helps support more accurate and timely billing – good news for you – and supports agents and suppliers in identifying consumption over time. This information not only supports the UK’s transition to a low-carbon energy system. It’s also a fundamental enabler for suppliers and other players in the energy market to create new products and services that benefit users.
If your glass is half full…
The implementation of MHHS could enable a range of new tariffs for customers, including time of use (ToU) tariffs that could be within-day or within-week, or vary across seasons. It may also allow your supplier or agent to spot and recommend ways for you to shift your demand and save money.
More broadly, a new HHS regime can support engagement in a range of flexibility services and encourage you to change your demand in return for payments. At present, these focus on reducing demand during peak periods; in future, they could include demand turn up to offset surplus renewable generation on the electricity system.
But, if your glass is half empty…
We can also consider flexibility to be a risk, because energy costs change throughout the day
All sites that are currently settled on a NHH basis are divided into different profile classes, depending on their consumption and metering configuration. This takes data from meter reads and applies it throughout the day and year based on a set, averaged profile. The transition to MHHS will use a more tailored and accurate approach to this profiling for NHH meters. And, if users upgrade to HH meters, the meters will measure consumption on a half-hourly basis.
Unless your demand follows the profile class curve exactly, your attribution of demand throughout the day will change. Depending on your tariff, this could mean you’re exposed to different costs. Customers without a ToU tariff will see no change. But those whose tariffs change throughout the day, or pass through some costs, could see a shift in their costs.
Customers that consume a higher proportion of their demand throughout the off-peak periods (e.g. overnight, early morning) could save money by switching to a more tailored ToU tariff (if available). In the future, summer afternoons are increasingly likely to be cheaper consumption periods due to an abundance of solar generation.
Meanwhile, customers that consume more during the peak periods – typically 4-7pm over the winter – are likely to face higher costs. This is because they’re using electricity when networks and the overall power system are stretched the most.
Customers can shield themselves from these costs through their tariff choices, such as opting for a fixed tariff that locks costs down. However, customers able to either change demand in response to these price signals, or invest in flexibility behind the meter, are likely to save money in the long run.
In summary
MHHS may not feel like a significant change in the short term and, for many customers, it isn’t. But it should probably prompt you to start thinking more about your power consumption, if you don’t already do so.
It’s likely that, in the not-too-distant future, there’ll be an opportunity to engage with a wider range of tariffs and products. So, it’s worth remembering that you can only consider and engage with confidence if you’re already familiar with how your business consumes energy.
Disclaimer
We’ve used all reasonable efforts to ensure that the content in this article is accurate, current, and complete at the date of publication. However, we make no express or implied representations or warranties regarding its accuracy, currency or completeness. We cannot accept any responsibility (to the extent permitted by law) for any loss arising directly or indirectly from the use of any content in this article, or any action taken in relying upon it.
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