How Much Do Solar Panels Save on Electricity Bills in the UK?

This article has been published as part of an advertising collaboration.

Solar panels can reduce how much electricity you need to buy from the grid, but the amount you actually save depends on your home, how much electricity you use while the panels are generating and whether you get paid for excess power you export.

If you’re wondering how much solar panels save on electricity bills, there isn’t one figure that applies to every UK home. The cost of the system and the time it takes to repay that investment matter just as much as the annual bill reduction.

According to Energy Saving Trust’s current solar panel guidance, an average domestic system costs around £7,600 to install. Its current examples suggest payback periods of roughly 9 to 12 years in several locations across Great Britain when export payments are included, although your own result can be shorter or longer depending on the property and how you use electricity.

There’s also a new, much smaller alternative to conventional rooftop solar. Plug-in solar panels are now legal in Great Britain, giving some households another way to generate electricity without installing a full roof-mounted system, and I’ve covered those separately later in this guide.

What's the cost of solar panels in the UK?

Energy Saving Trust currently puts the average cost of a domestic solar panel system at around £7,600, based on a typical system of about 4.5kWp. Your actual quote can be higher or lower depending on the number of panels, access to the roof, whether roof work is needed and the type of equipment you choose.

The purchase price is only half of the calculation because you also need to look at how much electricity you are likely to use yourself and what you can earn from exporting the rest. Energy Saving Trust’s current examples put payback at around 9 years in London and Aberystwyth, around 10 to 11 years in Manchester and around 11 to 12 years in Stirling, depending on when the household is at home.

Those figures include export payments and are based on electricity prices from July 2026.

For homeowners in the south of England, using an installer that understands local properties and planning requirements can make the process easier to manage.

If you’re looking specifically in Kent, a professional team offering kent solar pv installation can assess whether your roof is suitable and explain what sort of system could work for your home.

An installer should assess factors such as the direction and angle of your roof, shading and available space before estimating how much electricity a system could generate. They can also deal with the relevant grid-connection requirements and paperwork as part of the installation process.

Ask exactly what is included in the quote, as the level of support and any additional charges can vary between installers.

What if rooftop solar is too expensive? Plug-in solar is now an option

A full rooftop solar installation isn’t the only way to generate some electricity at home anymore. Qualifying plug-in solar panels can now legally be bought and used in Great Britain, giving households access to much smaller systems that connect to the home through a standard UK mains socket rather than requiring a conventional rooftop installation.

The new systems are limited to 800W, which is considerably less than a typical rooftop array. The government estimates that a qualifying plug-in solar kit could provide up to 20% of an average home’s electricity use and save up to £110 a year, but those are maximum estimates rather than a guarantee of what you will save. Your results will depend on where the panels are positioned, shading, weather and whether you are using electricity while they are generating it.

Plug-in solar could be particularly interesting if the £7,600 or so needed for a conventional system is simply out of reach, or if you don’t have a suitable roof. There are still rules to follow, including making sure the complete system meets the Great Britain specification, checking any landlord or freeholder restrictions that apply to your home and dealing with the relevant electricity-network requirements.

I’ve gone through all of those points in my full plug-in solar panels guide, including what the £110 figure really means, the likely payback calculation, the safety rules and what to check before spending money on a kit.

The benefits of solar energy

Installing solar panels is a significant upfront expense, so the financial case needs to stack up for your home rather than relying on broad claims about what solar can save. Panels generate most when conditions are bright, but they still produce electricity from daylight on cloudy days, which means the UK climate doesn’t stop them working.

How much electricity you generate will depend on factors such as where you live, the direction and angle of your roof, shading and the size of the system.

The main attraction is that electricity generated and used at home is electricity you don’t have to buy from your supplier. You may also be able to sell surplus electricity back to the grid, while a battery can let you keep some of it for use later in the day.

Those benefits need to be weighed against the installation cost and likely payback period before deciding whether solar works financially for you

Cut your electricity bill and sell surplus power

Solar panels can reduce the amount of electricity you need to buy from the grid, particularly if you can move some of your normal electricity use into daylight hours.

Running appliances such as a washing machine or dishwasher while your panels are generating means you use more of your own electricity rather than exporting it and buying power back later. The amount saved varies significantly between households, so I wouldn’t attach one headline annual saving to every 4kW or 4.5kWp system.

Electricity you don’t use can potentially earn money through the Smart Export Guarantee (SEG) in England, Scotland and Wales. The SEG requires participating suppliers to pay eligible small-scale generators for electricity exported to the grid, but suppliers set their own rates and terms, so there isn’t a guaranteed national price per unit.

It’s worth comparing export tariffs rather than assuming the company supplying your electricity will automatically give you the best deal.

Energy Saving Trust’s current examples put typical solar payback periods at roughly 9 to 12 years in different parts of Great Britain when export payments are included. Your own figure could be shorter or longer depending on the price you pay for the system, how much electricity you use yourself and the export tariff you choose.

That payback calculation is much more useful than assuming every household will save the same amount each year.

Could solar panels add value to your home?

Solar panels may make a property more attractive to buyers who value lower running costs, but I wouldn’t claim that they automatically add 10% to a home’s value. Older government research found a relationship between better EPC ratings and higher selling prices, but that research looked at the overall energy performance of homes rather than proving that solar panels alone created a particular percentage increase.

If you’re buying or selling a home with solar already installed, the age of the system, warranties, ownership arrangements and condition of the panels can all matter. Energy Saving Trust recommends checking who installed the system, what warranty remains and whether any parts may soon need replacing.

A well-documented system may be easier for a buyer to assess than one where nobody can explain its history.

Become less dependent on electricity from the grid

Generating electricity at home can reduce how much you need to buy from the grid, while battery storage can increase the amount of solar power you use yourself. A battery stores surplus electricity generated during the day so you can use it later, including during the evening or at times when your panels aren’t producing enough. That can be particularly useful if much of your electricity use happens after the sun has gone down.

A battery doesn’t automatically mean your home will keep running during a power cut. Energy Saving Trust says most battery systems won’t provide backup power unless the installation includes the additional equipment and configuration needed for that purpose. If power-cut protection is important to you, ask the installer specifically what the proposed system will and won’t power during an outage.

Reduce your environmental impact

Solar panels generate renewable electricity at home and can reduce the amount of grid electricity you need to buy. Energy Saving Trust estimates that a typical home solar panel system could save around one tonne of carbon a year, although the figure varies depending on where you live and how much electricity the system generates.

That environmental saving sits alongside the financial one, but the two won’t necessarily move at exactly the same rate. A household that uses a large proportion of its solar electricity while it is being generated may get more financial value from the system, while the carbon benefit also depends on the electricity being displaced.

It’s another reason to look at the complete system rather than judging solar purely from the number of panels on the roof.

What maintenance do solar panels need?

Solar panels generally need relatively little maintenance, but that doesn’t mean you can install them and forget about them completely. Energy Saving Trust says rain will normally help clean panels mounted at an angle of 15 degrees or more, while panels exposed to more dust, dirt or nearby trees may need occasional cleaning. You should also follow whatever inspection and maintenance guidance your installer provides.

The inverter is another cost to remember when working out the long-term finances. Energy Saving Trust says solar panels themselves should last 25 years or more, while an inverter will generally need replacing much sooner, at around 12 years. Allowing for that future expense gives you a more realistic picture of the lifetime cost than assuming there will never be another bill after installation.

How do solar panels perform in different UK weather?

Solar panels don’t need hot weather or cloudless skies to generate electricity. They work from daylight and continue producing power on cloudy days, although stronger sunshine generally means higher output. This means Britain’s weather doesn’t make solar pointless, but you should expect generation to change considerably across the year.

Winter brings shorter days and less solar generation, while the longer daylight hours of spring and summer provide much more opportunity to generate electricity. Your installer should model expected annual output using the location, orientation, shading and proposed size of your system rather than selling it on the basis of a best-case summer day. That annual estimate is the figure I’d use when comparing quotes and working out possible savings.

I’d remove the existing claim that panels routinely operate at “10-25% of peak capacity” on cloudy days because there isn’t one percentage that applies reliably across different panels, cloud conditions and installations. I’d also remove the suggestion that snow can meaningfully boost generation, as it adds complexity without helping somebody decide whether solar makes financial sense.

Are there any solar panel grants available?

There isn’t currently a universal government grant that simply pays for solar panels for any homeowner who wants them. Some households may qualify for support through schemes including the government ECO4 scheme , but ECO4 is targeted support rather than a general solar grant, and eligibility depends on the household and property.

The current ECO4 programme runs until the 31st of December, so anyone looking at this route should check their eligibility sooner rather than relying on it being available indefinitely.

There is also the Smart Export Guarantee (SEG), which can pay eligible households for electricity exported back to the grid. This isn’t a grant towards the installation cost, and suppliers are free to set their own export tariff rates and conditions. Comparing those rates can make a noticeable difference to the long-term return from a solar system.

Solar panels and certain other installed home energy-saving products currently also qualify for 0% VAT, subject to the rules of the scheme. The temporary zero rate is due to run until the 31st of March 2027, after which qualifying installations are scheduled to return to the reduced 5% VAT rate unless the government changes the rules again.

What should you look for when choosing solar panels?

Solar panel technology has developed considerably, but the specification on the product sheet is only part of the decision. If you’re comparing panels, Solen offers a range of solar modules, but you should still compare factors such as output, product and performance warranties, the size of the proposed system and the total installed price. The best option for one home won’t automatically be the best choice for another.

The installer matters just as much as the panels. A proper assessment should consider your roof orientation, shading, available space and expected annual generation before you agree to spend several thousand pounds. Energy Saving Trust recommends getting at least three quotes and using MCS-certified installers when comparing a conventional rooftop installation.

If you want another way of comparing companies in your area, a supplier comparison service such as SpotDif can help you look at solar providers operating locally. I’d still compare the actual proposals rather than choosing solely on price, because two quotes can cover different numbers of panels, inverter specifications, warranties, scaffolding and battery options.

Ask for the expected annual generation and complete installed cost in writing so you have something meaningful to compare.