Solar Panels for UK Homes: Is Your Roof Suitable and Is It Worth It?

Solar panels turn daylight into electricity, and they work in the UK even on cloudy days, though output is higher in sunshine. They can reduce the electricity you buy from the grid, but whether they make financial sense depends on your roof, your use and the price you pay for the installation. This guide covers the basics.

How a home solar system works

Panels on your roof produce direct current (DC) electricity. An inverter converts it to alternating current (AC) that your home can use. Whatever you generate and use at the time reduces what you import. If you produce more than you use, the surplus can be sent to the grid, and you may be paid for it under a Smart Export Guarantee tariff. See our guide to the Smart Export Guarantee. You can also store surplus in a home battery.

Is your roof suitable?

• Direction: south-facing roofs produce the most in the UK, while east and west can still work well, especially if you use more electricity in the morning or evening.
• Angle: a pitch of around 30 to 40 degrees is often ideal, but flatter and steeper roofs can work.
• Shade: trees, chimneys and neighbouring buildings can reduce output substantially. Even partial shade can matter, so ask about optimisers or microinverters.
• Space and condition: you need enough clear roof area, and the roof should be in good condition because panels are costly to remove and refit.
• Structure: a surveyor or installer should check that the roof can carry the weight.

How much will it generate?

A system's size is given in kilowatts peak (kWp). As a rough guide, each kWp in the UK can generate in the region of 800 to 1,000 kWh a year, depending on location, orientation and shading. A good installer will give you a site-specific estimate. Treat optimistic claims with caution and ask how the numbers were calculated.

Does it pay back?

The saving depends on how much of the electricity you use yourself, because that is worth more than the price paid for exported power. Households that are home during the day, or that have a battery or electric vehicle, tend to use more of their solar. Work out payback by comparing the installed cost with the yearly value of electricity you will use and sell. Remember that the panels degrade slowly, the inverter may need replacing during their life and electricity prices can rise or fall.

VAT and grants

According to HMRC guidance, the installation of solar panels and batteries in Great Britain is zero-rated for VAT until 31 March 2027, after which the reduced rate is due to apply. Check the current position when you request quotes. Grant support for solar has varied over time, so check GOV.UK and your local council.

Choosing an installer

1. Choose an installer certified under the Microgeneration Certification Scheme (MCS), which is needed to claim export payments in most cases.
2. Get at least three written quotes with the system size, panel and inverter brands, expected generation and warranties.
3. Ask about guarantees, insurance-backed warranties and what happens if the installer ceases trading.
4. Be cautious about doorstep sales or pressure to sign quickly.

Planning and other points

Most domestic installations fall under permitted development, but listed buildings, conservation areas and some flats have restrictions, so check first. Tell your network operator about your installation, as your installer should do on your behalf, and inform your home insurer.

Solar works best in an efficient home. Cut waste first with the ideas in our energy-saving guide, then consider generating your own power.