What is Market-wide Half-Hourly Settlement?

MHHS is the industry reform that settles every electricity meter on its actual half-hourly consumption, using smart meter data, instead of averaged profiles. Migration began in late 2025, with most meters transitioning between May 2026 and May 2027.

Will half-hourly settlement raise my business energy costs?

It depends on your usage shape. Sites that draw heavily in the expensive evening half-hours will face cost-reflective pricing; sites that can shift load — or serve it from solar and a battery — gain access to tariffs that reward exactly that flexibility.

What should a business do about it?

Get hold of your half-hourly data and understand your shape. That same data is what a solar and battery system is sized from — and the flatter, cheaper profile the system creates is precisely what the new market rewards.

Half-hourly settlement is coming to every business: what it means for your energy costs

The UK electricity market is part-way through its biggest settlement reform in decades — and it changes what your business pays for power in a way most bill-payers haven’t clocked yet. In short: when you use electricity is becoming as important as how much.

What’s changing

Historically, most business and domestic meters were settled against averaged usage profiles — your supplier estimated the shape of your consumption and priced accordingly. Market-wide Half-Hourly Settlement (MHHS), run by the industry under Ofgem with Elexon as senior responsible owner, settles every meter on its actual half-hourly consumption from smart meter data. Migration of meters began in late 2025, with the majority transitioning between May 2026 and May 2027.

Why it changes your bill

Once every half-hour of your consumption is priced as itself, suppliers can — and increasingly will — offer tariffs that reflect real system costs half-hour by half-hour. Electricity at 6pm on a cold still evening costs the system far more than at 1pm on a sunny breezy afternoon, and cost-reflective tariffs pass that difference through. Two businesses using identical annual kWh can end up with very different bills, purely on shape.

If your load peaks in the expensive half-hours — evening production runs, kitchens at dinner service, refrigeration through hot afternoons — cost-reflective pricing works against you.
If you can shift load, or serve it from your own generation and storage — it works for you, and the incentive to do so is growing.

The solar-and-battery answer

This reform is, in effect, the market moving toward the logic a solar-plus-battery system already runs on. Solar takes your daytime consumption off the grid entirely. A battery moves cheap or self-generated energy into the expensive half-hours and flattens the peaks that drive charges. And because tariffs now differ half-hour by half-hour, automated operation matters: Nova AI re-optimises the battery every 30 minutes against live prices — the exact granularity the market now settles on.

Start with your data

Your half-hourly data is the raw material — for understanding your exposure under MHHS, and for sizing a system that fixes it. It’s also precisely what a Novalux proposal is built on: send it with a Quick Quote request and we’ll show your consumption shape, what it costs you, and what a system sized to it returns over 25 years.