How long do home solar panels take to pay for themselves?

The short answer

A typical 3.5kW rooftop system costs £6,500 on the government’s figures and saves around £500 a year, so it pays for itself in about 13 years.

Counting what the money could earn in savings, and letting electricity prices rise or fall, the break-even point runs from 10 to 25 years across the scenarios below. Over 30 years, solar ends ahead in every one of these simplified scenarios. They assume the panels work for all 30 years, longer than the Energy Saving Trust’s 25, and leave out repairs and any fall in output.

These figures describe Great Britain. Northern Ireland’s electricity market works differently, and the price cap, export payments and cost figures here do not cover it. The government publishes what a battery costs and what solar with a battery can save, but from different sources, so this guide works no payback for that.

A payback period is an illustration, not a forecast. The published saving rests on the energy price cap of April 2025, when electricity cost 27.03p per kilowatt hour (kWh) on average, including VAT. From October 2026 it costs 26.32p with no VAT, so each unit a home makes for itself saves a little less than when the saving was worked out.

Solar panels on their own

The government’s Solar Roadmap, published by the Department for Energy Security and Net Zero (DESNZ) on 30 June 2025, gives both halves of the sum.

• What it costs. A typical 3.5kW rooftop system cost £6,500 in 2024/25. A kilowatt (kW) measures a system’s peak output. The figure is the median price for systems up to 4kW, rounded to the nearest £500. The same system cost around £9,000 in 2013/14, in 2024 prices.
• What it saves. A typical home could save around £500 a year, for a 3.5kW south-facing system at the April 2025 price cap. The estimate comes from the government’s Home Energy Assessment tool. The roadmap does not say whether it counts payment for electricity sold to the grid.
• The payback. £6,500 divided by £500 a year is 13 years.

That sum, called simple payback, leaves things out. It holds the saving the same every year, while electricity prices rise and fall. It ignores what the money could have earned elsewhere. It also leaves out repairs, such as replacing the inverter, the box that converts the panels’ output for household use.

What the published cost covers

DESNZ’s cost figures include the equipment, installing it, connecting it to the electricity supply and any VAT. They leave out a battery, any extended warranty and other work on the system. They come from installations registered with the Microgeneration Certification Scheme in Great Britain.

The payback clock starts only once the system is connected and working. The Solar Roadmap says systems above 3.68kW per phase generally need the local network operator’s approval first. Some installers stop at 3.68kW to avoid that step. Under Fast Track, for generation smaller than 14.72kW, the operator must still approve it, but the response period is now 10 working days.

Solar panels with a battery

A battery stores daytime output so the home can use it in the evening rather than buy from the grid.

DESNZ publishes what households paid to add a battery to an existing home, for each kWh of energy it can store. The median costs in 2025/26 were:

• Batteries of 1 to 5.99kWh: £1,300 per kWh.
• Batteries of 6 to 10.99kWh: £890 per kWh.
• Batteries of 11 to 29.99kWh: £630 per kWh.

Larger batteries cost less for each kWh they hold. The cost covers the battery, installing and connecting it, and any VAT. It leaves out solar panels fitted at the same time.

The Warm Homes Plan gives these yearly bill savings in its examples:

• Solar panels and a battery, for an owner-occupied three-bedroom mid-terrace: £450 a year.
• Charging the battery off-peak on a time-of-use tariff: up to £300 a year more.
• A heat pump, solar panels and a battery, in place of a gas boiler: £450 to £550 a year.

A time-of-use tariff charges different prices at different times of day. The plan bases its figures on average energy prices for 2024, for a household in Yorkshire.

The £450 for solar with a battery sits below the roadmap’s £500 for solar alone. The two come from different documents, for different homes and price years, so neither shows what a battery adds on its own. The battery costs come from a third source, so this guide works no payback for a battery.

With a quote in hand, the same sum applies. The installed cost is divided by the yearly saving, where the saving is the bill saving plus any export payment not already counted in it.

Export payments

A solar home saves in two ways. Each unit it uses itself is a unit it does not buy, and each unit it sends to the grid can earn an export payment.

In Great Britain, export payments come through the Smart Export Guarantee, run by Ofgem, the energy regulator. It covers installations up to 5MW. GOV.UK sets out these conditions for a home system:

• The installation and its installer are certified under the Microgeneration Certification Scheme, or a scheme accredited as equivalent.
• A meter records exports every half hour. This is usually a smart meter.
• The home is not already paid for its exports under the older Feed-in Tariffs scheme.

Suppliers that offer it set their own rate, which Ofgem says must always be above zero. There is no single official export rate, so the sum here adds none to the published saving, which may already count some.

Under UK law as it stands, payments for exported electricity are free of income tax. That holds where the system is at or near the home the household lives in, and is meant to generate not much more than the home uses. The law could change.

A unit used at home is worth what the household would otherwise pay for it. Under Ofgem’s price cap for 1 October 2026 to 31 December 2026, electricity on a default tariff paid by Direct Debit costs 26.32p per kWh on average. The standing charge is 54.83p a day, and both are averages across England, Scotland and Wales. Those prices leave out VAT, which the government has removed from electricity bills until the end of March 2027.

Electricity prices over five years

The price of household electricity in the UK rose 46% between August 2021 and August 2026, about 7.9% a year. Consumer prices as a whole, measured by the all-items index, rose 28%, about 5.1% a year.

The rise came in jumps and falls. Year on year to each August, electricity prices rose 54%, then 7%, fell 19%, then rose 8% and 2%. At their highest, from January to March 2023, they were 82% above August 2021.

Five years of past prices say nothing certain about what comes next. They show how far prices can swing, which is why the comparison below tests several rates.

Solar or savings over 30 years

Take the same £6,500 two ways. Left in savings, it earns interest each year. Spent on panels, it lowers the electricity bill each year, and this comparison banks each year’s saving so it earns the same interest as the savings would.

Break-even is the year the solar option catches up. After it, no more money goes in and the bill savings keep coming, growing when electricity prices rise. At 5.1% a year, the yearly saving grows from £500 to about £2,100 by year 30.

After 30 years the savings option holds £6,500 at 0% and £19,600 at 3.75%. The table sets the solar option beside it, rounded to the nearest £100.

The 5.1% and 7.9% are the past five years’ rises in all prices and in electricity. The fall of 2% a year is an assumption, added to show a downside. The 3.75% is Bank Rate as set on 17 September 2026, a reference point only. The comparison holds each rate for all 30 years. No saver is promised it, and none of these rates is a forecast.

What the comparison leaves out:

• How long panels keep working, and how their output falls with age. No government figure for either was found. The Energy Saving Trust says a system can be expected to last 25 years, fewer than the 30 here, which are an assumption.
• Repairs, which would reduce the solar option. The Energy Saving Trust says an inverter needs replacing after around 12 years, and gives no cost.
• Any value the system adds to the home, or takes from it, on a sale.
• Tax on savings interest, which turns on a person’s own position.
• Inflation. The figures are in pounds of each year, not today’s money.
• Access. Money in an easy-access savings account can be drawn on at any time. Money in panels cannot.

Warranties

Many manufacturers give a multi-year warranty. On the manufacturers’ own pages read for this guide, a product warranty, which covers defects in the panels, runs from 20 to 25 years. A power warranty, which promises the panels keep a stated share of their original output, runs from 25 to 30 years.

Terms differ by model and by country, and a panel warranty covers the panels rather than the inverter or the installation. The Energy Saving Trust says most inverter warranties run at least 5 years. The terms on a quote are the ones that apply.

VAT, and what moves the payback

Installing energy-saving materials in a home, which include solar panels and batteries, is zero-rated for VAT up to and including 31 March 2027. From 1 April 2027 the rate is 5%, which is legislated. The zero rate applies to qualifying installations across the UK, including Northern Ireland. Panels or a battery bought without installation, such as from a shop, are charged VAT at the standard rate, HMRC says.

A household’s own payback can sit well away from the published figure. The main things that move it are:

• The price paid for the system.
• The share of output used at home rather than exported.
• The export rate a supplier pays.
• The price of each unit bought from the grid. Ofgem sets the cap on default tariffs every three months in Great Britain, and other tariffs change on their own terms.
• The roof’s direction, pitch and shading.
• Repairs and replacement parts over the system’s life.

In a retirement plan, money spent on panels is money not held in savings or investments: a lump sum now for lower bills later. A household that moves before the payback year will not yet have recovered the cost through bill savings, though a sale and the other things left out here can change the overall result.

This guide informs. Whether solar suits a home turns on its roof, its electricity use, the price quoted and the household’s wider plans. MoneyHelper gives free, impartial guidance, and a regulated financial adviser can advise on your own case.

Other costs that carry on in retirement

How Landfall handles it

Large costs arrive in lumps. A roof, a boiler, a kitchen or a replacement car is a one-off event in Landfall, not a cost spread across every year.