If you fit solar panels in the UK, you can use the electricity yourself, send the surplus to the grid, or do both. The Smart Export Guarantee (SEG) is the scheme that pays you for what you export. There’s no grant for the panels themselves, so understanding SEG is a big part of deciding whether solar is worth it.
What SEG is
SEG is an Ofgem-backed scheme that requires larger licensed electricity suppliers, those with at least 150,000 domestic customers, to offer at least one export tariff. Smaller suppliers can choose to offer them too. Suppliers set their own rates, so there’s no government price. The only rule is that the rate has to be above zero.
What you need to qualify
You’ll need a solar installation certified under the Microgeneration Certification Scheme (MCS), fitted by an MCS-certified installer. You’ll also need a meter that records how much you export, which for most homes means a smart meter. Your installer usually deals with notifying your network operator and registering the system, but ask them to confirm what they’ll handle.
What rates look like
Rates vary a lot. Standard tariffs are often somewhere between a few pence and about 15p per kWh, while some tariffs tied to a battery, or to buying your electricity from the same supplier, pay more. They change often, so compare current offers before you choose, and look again once a year. You can usually switch export supplier, and it’s a short job.
The thing to keep in mind is that electricity you import typically costs two to three times what you earn for exporting. Using your own solar power is almost always worth more than selling it.
What solar costs
In 2026, a typical 4kW system for a home often costs about £6,500 to £8,500 installed, and adding a battery can take the total to £10,000 or more. Prices differ by region, roof and installer. Installations may currently be charged at 0% VAT, but check the current rules with your installer.
A worked example (illustration only)
Say a 4kW system produces 3,500 kWh a year. You use 40% yourself (1,400 kWh) and export the rest (2,100 kWh). If imported electricity costs 27p per kWh, using your own solar saves about £378. If your export tariff pays 12p per kWh, exporting earns about £252. That’s roughly £630 a year, so on a £7,500 system simple payback is about 12 years. If you used more of the power yourself, payback would be shorter. Replace each number with your own before you rely on it.
Making the most of it
Run the washing machine, dishwasher or hot water when the sun is out, so you use more of your own power. A battery can help if you’re out all day, but it adds a lot to the cost, so check that it pays back. Compare export tariffs at least once a year. Pairing solar with a heat pump or an electric vehicle raises your own use, which is one reason the two often go together. Our heat pump and gas boiler guide covers the heating side.
Fixed or variable?
Some export tariffs are fixed for a set period, others follow the supplier’s wholesale prices or the time of day. A fixed rate is easier to plan around, and a flexible one can pay more if you can shift your use or export at the right times. Neither is automatically better. The right choice depends on how you use your power, and whether a supplier’s best rate comes with conditions such as being their electricity customer.
Roof, orientation and shade
A south-facing roof gets the most sun, but east-west roofs work well too and can spread generation across the day. Shade from trees or chimneys can cut output more than people expect, so ask your installer to account for it in the estimate. The condition of the roof matters, because you don’t want to remove panels in a few years to fix tiles, and scaffolding is a real cost. Solar on a house is often permitted development, though listed buildings and some conservation areas have different rules, so check before you commit.
A few common questions
Is there a grant for solar panels? There’s no general national grant. The Boiler Upgrade Scheme covers heat pumps, not solar.
Is SEG income taxable? HMRC’s rules can depend on your situation, so check with an adviser if you’re unsure.
To compare solar against other upgrades, use our UK calculator.