Is Ofgem’s biggest reform about to stumble before it starts?
The Market-wide Half Hourly Settlement (MHHS) programme promises a smarter, fairer energy market. Yet data flaws buried deep in Britain’s metering system could derail its £4.5 billion in expected benefits.
That’s the warning from energy data firm Stark. In its new report Bad Data, Broken Energy System, the company claims a third of the nation’s 35 million meters — around 11.6 million — are not sending accurate Half-Hourly data.
Many could do so but are misconfigured or poorly maintained.
Stark says suppliers still rely on estimated readings and manual inputs that inflate costs and damage trust.
Only a third of suppliers currently meet Half-Hourly standards, covering just 12% of consumption. In the Non-Half-Hourly market, fewer than one in five make the grade.
Under the new regime, suppliers’ costs will depend on data quality.
Stark’s modelling suggests performance could swing financial exposure by up to ±£21 million a year per supplier.
Poor data means penalties. Strong data earns payouts.
The system balances overall but the stakes for individual firms are high.
Despite the concerns, the first migration phase began this week.
By July 2027, all suppliers must settle accounts using actual consumption data within seven working days.
Stark’s Chief Executive Alex Warren said: “Manual readings alone cost the market more than £200 million a year and only five of nineteen agents have qualified for the new Advanced Data Service role.”
He added: “Half-Hourly Settlement is essential for a fair, flexible energy market, but the system can only work if the data behind it is reliable. The technology exists — what’s missing is performance and accountability.”
Without that, Warren warned, Ofgem’s biggest reform “risks failing before it has even begun.”
Will data disaster scupper MHHS? appeared first on Energy Live News.