On 30 September 2026 the energy consultancy Cornwall Insight published a forecast for the January 2027 energy price cap. It expects the cap to reach £1,999 a year for a typical dual-fuel household paying by direct debit — £276, or about 16%, above the October level, and the largest quarterly rise since January 2023.
What the forecast actually says
Cornwall Insight attributes the rise to wholesale gas: “This substantial increase is largely driven by the escalating conflict in the Middle East, which continues to disrupt gas supplies to the UK and the rest of the world.” It also points to EU gas storage sitting around 65% full at the beginning of September, well below the long-term average for the time of year. Because the observation window Ofgem uses to set the January cap is already close to half over, the consultancy describes a January increase as all but certain, even if the exact figure moves.
Two things are worth keeping straight. First, this is a forecast by a consultancy, not a decision by the regulator: Ofgem sets the cap and announces the January figure in late November. Second, the cap limits unit rates and standing charges, not your total bill — the widely quoted annual figure describes a household using a typical amount of energy.
Where the cap stands today
The cap in force from 1 October 2026 to 31 December 2026 sets electricity at 26.32p per kWh with a standing charge of 54.83p a day, announced by Ofgem on 26 August 2026. Separately, the government removed VAT from domestic electricity bills from 1 October 2026 until 31 March 2027, so that rate is what a capped household pays rather than a pre-VAT figure.
What it means for plug-in solar
- Savings come from the unit rate, not the bill. A plug-in system cuts the electricity you buy while it is generating. It does nothing about the standing charge, which you pay whether you generate or not. So the number that matters is pence per kWh, and that is the number the forecast says is going up.
- A higher unit rate raises the value of self-consumption. Every kWh you use as it is generated is a kWh you do not buy. If unit rates rise in January, the same system saves more money for exactly the same output — see self-consumption and the payback period.
- Winter output is the catch. January is the worst month of the year for solar generation in the UK, so a January rise in the unit rate does less for a plug-in owner than the same rise in June would. Judge a system on a full year, not on one quarter.
- Do not re-run your sums on a forecast. Our calculator uses only caps Ofgem has announced, and it defaults export income to zero. We will add the January period when Ofgem publishes it.
If you are weighing up a kit, the more useful questions are how much of your electricity you actually use during daylight and whether the exact model is listed as compliant on the ENA register. See whether plug-in solar is worth it and the kits the register lists as compliant.