As the UK adjusts to Ofgem’s Market-wide Half Hourly Settlement (MHHS), a leading energy data specialist, Stark, cautions that poor data quality and unreliable metering risk undermining the entire programme’s promised savings and operational flexibility.
MHHS itself marks the largest overhaul to the UK’s energy settlement framework, with the transition requiring all non-domestic electricity meters, including those serving HVAC and building management systems, to report accurate, timely half-hourly consumption data.
Despite these ambitions, Stark’s recent report, Bad Data, Broken Energy System, finds that around 11 million installed meters are either badly configured, poorly maintained, or not properly set up for smart, remote reads. This ongoing reliance on manual estimates continues to drive up costs and diminishes trust in the system, while also affecting the reliability of metered energy data for building services and plant operation.
Only a third of suppliers currently meet the new half-hourly data standards, and fewer than one in five agents achieve existing non-half-hourly benchmarks, both of which present obstacles for HVAC installers aiming to design and install efficient, trustworthy building systems that support performance and net zero strategies. The widespread use of manual data collection and legacy devices continues to hinder efforts to optimise HVAC energy usage and carbon reduction initiatives.
Furthermore, with the new MHHS charging regime, suppliers who fail to bring smart and advanced meters online will face significant financial penalties, in fact, Stark’s modelling suggests this could mean swings of up to £21 million per supplier, per year. For building portfolio owners and HVAC contractors responsible for metered sites, regulatory exposure and rising costs are now real risks. Nationally, manual readings alone contribute more than £200 million in extra costs annually to the energy market.
Alex Warren, Chief Executive of Stark, commented: “Half Hourly Settlement is essential to unlock smart, flexible energy use, including for HVAC integration, load shifting, and real-time control. However, it simply will not work with old habits and outdated metering. Reliable data is the bedrock of building optimisation. The technology exists, but without a sustained commitment to performance and accountable partners, the intended benefits of MHHS for building services and the wider energy market could simply evaporate.”
MHHS migration began in October, with early supplier waves due by July 2026 and full implementation required by July 2027. This timetable means urgent action for the HVAC sector: organisations must prioritise system upgrades, establish robust data protocols, and partner with trusted agents who offer remote monitoring capabilities, thereby avoiding costly manual visits and minimising their exposure to penalties.
The full report is available for download at https://www.stark.co.uk/register-interest-mhhs/
