How Much Can Solar Panels Save You in the UK?

The short answer: the Energy Saving Trust puts typical savings for a home with a 3.5kWp solar system at up to around £610 a year, against a typical installed cost of roughly £6,100. Some households save less than that, some save more — and the difference comes down to a handful of factors you can actually understand before you spend a penny.

This guide walks through where the savings come from, shows a worked example with the assumptions visible, and is honest about the things that shrink the numbers as well as the things that grow them.

Why there is no single answer

Any installer who quotes one guaranteed savings figure for every house is guessing. Four things move the number:

• How much electricity you use, and when. Solar generates in daylight. A household that runs the washing machine, dishwasher and car charger during the day uses far more of its own free power than one that is empty until 7pm.
• System size and roof orientation. A 3.5kWp array on an unshaded, southerly roof generates around 3,000kWh a year in typical UK conditions. East–west roofs still perform respectably; heavy shading is the real enemy.
• What you pay for electricity. Under the Ofgem price cap for July to September 2026, the average unit rate is 26.11p per kWh. Every unit your panels supply is a unit you do not buy at that price.
• What you are paid for exports. Smart Export Guarantee rates vary widely between suppliers — Ofgem data shows exporting households earned an average of 13p per kWh in 2024–25.

The two ways panels pay you back

1. Electricity you do not have to buy. This is the bigger lever. Every kilowatt-hour of solar power you use directly replaces a unit at your full import rate — 26.11p on an average capped tariff right now. Use 1,000 solar units a year at home and that is roughly £261 that never leaves your account.

2. Electricity you sell. Whatever you do not use is exported, and under the Smart Export Guarantee your chosen supplier pays you for it. Export rates are lower than import rates — that gap is exactly why using your own power first matters, and why many households add battery storage to close it.

A worked example, with the assumptions shown

Take a 3.5kWp system generating 3,000kWh a year, in a home that manages to use 40% of that power directly — a realistic figure for a household that is out during weekdays but shifts some appliance use to daylight hours.

• Self-used: 1,200kWh × 26.11p = around £313 saved off the bill
• Exported: 1,800kWh × 13p = around £234 earned in SEG payments
• Total benefit: roughly £547 a year

Shift more of your usage into daylight hours, or pick one of the stronger SEG tariffs on the market, and you close in on — or pass — the Energy Saving Trust’s “up to £610” figure. Leave everything running on an evening pattern with a low export rate, and you land under it. The assumptions are the answer, which is why a survey should always be built on your actual bills.

These illustrative figures use the July–September 2026 average capped unit rate and Ofgem’s 2024–25 average export earnings; your tariff will differ.

Where you live nudges the result as well. The south of England sees more bright hours than the UK average — our solar panels Surrey guide starts from Wisley’s 1,584 recorded sunshine hours a year — while the strongest case for Hampshire solar savings is often in off-gas-grid homes, where self-generated power displaces more expensive energy.

What a system costs in 2026

The Energy Saving Trust’s guide price for a typical 3.5kWp installation is around £6,100, including panels, inverter, mounting and labour. Larger systems cost more but usually less per panel, because the scaffolding, labour and paperwork are largely the same job.

Two cost points worth knowing this year:

• VAT is 0% until 31 March 2027. Residential installations of solar panels — and battery storage, fitted with panels or on its own — are zero-rated in Great Britain under HMRC’s VAT notice 708/6. From April 2027 the rate is due to return to 5%.
• There is no general grant for household solar in England, so treat any “government-funded solar” pitch with caution. The real support is the 0% VAT window and the export payments above.

How long until it pays for itself?

Divide cost by annual benefit and the arithmetic lands in the 10–12 year range for a typical system — the Energy Saving Trust’s own estimate is a break-even inside 12 years for many homes. Panels are designed to last 25 to 30 years, so a system that clears its cost in year 11 has well over a decade of very low-cost electricity still ahead of it. The inverter may need replacing once in that lifetime — typical manufacturer warranties run around 5 to 12 years — and it is sensible to factor that into your sums.

Rising import prices shorten payback; falling prices stretch it. Nobody can promise you a tariff forecast, and we would be wary of anyone who tries.

Five ways to make the savings bigger

1. Run appliances in daylight. Timers and smart plugs are the cheapest efficiency upgrade you will ever buy.
2. Consider a battery. Storing surplus daytime power for the evening raises self-use sharply — our battery storage guide covers costs and realistic payback.
3. Charge an EV from your roof. If you drive electric, solar and a home EV charger are a natural pair: daytime charging soaks up surplus generation at zero marginal cost.
4. Shop the SEG market. Rates in mid-2026 span a few pence to 15p or more per kWh, and you do not need to export to the same supplier you buy from.
5. Size the system to your usage. Oversizing sends cheap exports to the grid; undersizing leaves roof space earning nothing. The survey arithmetic matters more than the brochure.

The honest caveats

Solar will not take your bill to zero — you will still buy electricity on winter evenings, and standing charges apply regardless. Generation in December is a fraction of generation in June. Shading from chimneys, dormers or mature trees needs designing around, not ignoring. A north-facing roof with no other option is usually a poor candidate, and a decent installer will say so rather than sell to you anyway.

None of that changes the underlying position: at 2026 electricity prices, with 0% VAT and panels lasting 25–30 years, a well-sized, well-sited system is one of the few home improvements with a visible financial return — you can read more about how we install them on our solar panels page.

Want numbers for your actual roof?

A generic article can only take you as far as typical figures. If you would like the calculation done properly for your home — your roof, your usage, your tariff — request a free, no-obligation survey through our contact page. No pressure, just clear advice, and the arithmetic shown in full so you can check it yourself.