Energy bills, solar and batteries

The Ofgem price cap: 1 October to 31 December 2026

The cap limits the unit rates and standing charges on standard variable (default) tariffs. It doesn't cap your total bill: use more energy and you pay more.

For a typical dual-fuel household on Direct Debit (2,500 kWh of electricity and 9,500 kWh of gas a year), that works out at £1,723 a year, up 4% from £1,663 in July to September 2026. Ofgem says its electricity figures for this period include no VAT, because none is charged on domestic electricity from 1 October 2026 to 31 March 2027. The gas figures include 5% VAT. Your rates depend on your region and how you pay.

Fixed vs variable deals

• Variable (default) tariffs move with the cap every three months.
• Fixed tariffs lock your unit rates and standing charges for a set period. Your bill still rises if you use more.
• What to compare: the unit rate, the standing charge, exit fees (and how long they apply), contract length, and how the deal compares with the current cap. A low unit rate with a high standing charge can cost more if you use little energy.

Time-of-use and EV tariffs

Time-of-use tariffs charge different rates at different times. Typically there's a cheap overnight window of a few hours, and some have a pricier peak in the early evening. They usually need a smart meter. They suit households that can shift use – charging an electric car, running a home battery, or using appliances on timers – into the cheap hours. Economy 7 is an older version with seven cheaper night hours. Check the peak and day rates as well as the cheap rate: if you can't shift much, they can cost more than a standard tariff.

Why solar panels?

• Cost: the Energy Saving Trust puts the average home system at around 4.5 kWp (about 12 panels, 20–30 m² of roof), costing around £7,600 to install. The cost depends on size, roof access and whether you need scaffolding.
• Generation: output depends on location, orientation and shading. Per the Energy Saving Trust, east- or west-facing roofs get around 15–20% less energy than south-facing ones. Use the Energy Saving Trust solar calculator for an estimate for your home. As a rough example only, a south-facing system might produce somewhere around 850 kWh a year per kWp in much of England – an assumption, not a quote.
• Smart Export Guarantee (SEG): in England, Scotland and Wales, licensed suppliers with 150,000 or more customers must offer a tariff that pays you for electricity you export to the grid. The installation usually needs to be MCS-certified, and you'll need a meter that can record exports. Rates vary by supplier and must be above zero.
• 0% VAT: installing qualifying solar panels, and batteries (with or without solar), in homes in Great Britain is zero-rated for VAT until 31 March 2027. After that it's due to return to 5%.
• Solar panels on houses are usually "permitted development", but check if you're in a listed building, conservation area or national park.

A battery without solar

A home battery can be charged on a cheap overnight time-of-use rate and then power your home at peak times, when you'd otherwise pay the full rate. Whether that pays back depends on the gap between the two rates, how many full cycles you use, the battery's efficiency, and its price and lifespan.

Home battery saving and payback

Defaults: the peak rate is the October–December 2026 price-cap average unit rate (26.32p). The cheap rate (7p), battery cost (£4,000), efficiency and lifespan are example figures only, not real prices. Replace them with your own quote and tariff.

Usable battery capacity (kWh)

Round-trip efficiency (%)

Cheap rate (p/kWh) example

Peak rate you avoid (p/kWh)

Full cycles per year

Installed cost (£) example

Lifespan (years)

Capacity loss per year (%) example

First-year saving–

Payback (with degradation)–

Net gain over lifespan–

Assumptions: each cycle fully charges at the cheap rate (energy bought = capacity ÷ efficiency) and fully discharges into your own use at the peak rate. You need enough peak-time demand to use it. Battery capacity falls each year by the degradation rate. Tariffs stay the same. Standing charges, tariff changes, maintenance, inverter replacement and the time value of money are ignored. Illustration only.

Sources (checked 12 October 2026): Ofgem – Energy price cap unit rates and standing charges (1 Oct – 31 Dec 2026); Ofgem – Energy price cap will rise by 4% from October 2026 (26 Aug 2026); Energy Saving Trust – Solar panels: costs, savings and benefits; Ofgem – Smart Export Guarantee (SEG); GOV.UK/HMRC – VAT Notice 708/6: energy-saving materials and heating equipment.