Ofgem Time-of-Use Price Cap Review: Solar and EV Owners

Ofgem has opened a call for input on how the time-of-use price cap should work once half-hourly electricity settlement is in place. Published on 12 October 2026, it matters most to homes with a solar battery, an EV or a heat pump, because those are the households Ofgem expects to benefit from shifting demand — and the ones whose costs the current cap handles least well. Nothing changes yet: this is early-stage thinking, and responses close on 20 November 2026.

What Ofgem has actually published

A call for input, not a proposal. Ofgem's paper sets out the case for change and three broad options, and says it is seeking feedback on option design and assessment before developing its approach further. It does not announce a new cap level or a decision.

Why now. Ofgem says Market Wide Half Hourly Settlement (MHHS) will bill suppliers on customers' actual half-hourly usage rather than estimated profiles, so suppliers pay more for customers who use power at peak times and less for those who move it. It expects that to push more suppliers to offer time-of-use tariffs. Around 24 million electricity supply points had migrated by September 2026, with the rest due by May 2027.

The cap in question. Ofgem already sets a separate “multi-register” cap for tariffs with more than one unit rate. In October 2026 the direct debit level is £1,046 at 3,400 kWh of typical use. Suppliers can set their own peak and off-peak rates as long as the demand-weighted average stays at or below that level. For Economy 7 the assumed split is 52% off-peak and 48% peak. Our price cap explainer covers the main single-rate cap.

The three options on the table

Option 1: a simple two- or three-band tariff. Ofgem would set prescriptive unit rates for each time band instead of capping the average. That gives similar customers a more consistent default tariff and makes comparison easier, but it stays one-size-fits-all and the price signals are blunt.

Option 2: type-of-use caps. On top of a central time-of-use cap, Ofgem could set variants for different customer types — the paper specifically mentions an EV variant and a heat pump variant, and says solar could also be considered. The difficulty is identifying who belongs in each group and estimating their demand profile, especially for someone with an EV, heat pump and battery together.

Option 3: tariff-specific assessment. Suppliers would build their own demand profile for a given tariff using half-hourly unit costs supplied by Ofgem, and Ofgem would check the profile and the customer group are appropriate. Ofgem calls this the most cost-reflective option but the most complex to design and police.

Why solar, battery and EV owners should care

The current single profile undervalues flexibility. Ofgem says one demand profile for all time-of-use customers undervalues the savings multi-rate customers create by using more energy outside peak periods, and may mean some customers pay above their cost to serve while others pay below. Households that charge a car overnight or run a battery on cheap rates are exactly the group in question.

Better-matched defaults. If Ofgem moves towards option 2 or 3, a household with an EV or battery that falls back onto a default tariff could be priced against a profile that reflects how it actually uses power. If you are already on a smart tariff, see our guide to time-of-use tariffs for solar owners and our comparison of the best EV charging tariffs.

Smart meter data matters. Ofgem expects the immediate effect to be limited by customer consent to share half-hourly data and by low uptake of time-of-use tariffs so far. Our guide to smart meters with solar panels explains what a meter does and does not do for export.

What happens next

Timeline. Ofgem aims to bring in a new single-rate demand profile and allowances in spring 2027, subject to market conditions. The time-of-use redesign is more complex: its initial plan is incremental change by the second half of 2027. Anything affecting bills would follow a formal consultation first.

What you should do now. Nothing is required. If you have a view — as a consumer, installer or community group — you can respond to priceprotectionpolicy@ofgem.gov.uk by 20 November 2026. Otherwise, keep checking your own tariff; our Octopus tariffs for solar owners guide is a practical starting point.