The Smart Export Guarantee Explained: How SEG Works

The Smart Export Guarantee (SEG) makes energy suppliers pay you for surplus solar power that you send to the grid. It began on 1 January 2020. To qualify, your system must be MCS-certified and you need a meter that records your exports. Each supplier sets its own rate, so tariffs differ.

How SEG works

When your panels make more power than your home uses, the extra flows out to the grid. Your meter records it, and a supplier then pays you for every kilowatt-hour (kWh) you export.

Ofgem runs the scheme, and suppliers with at least 150,000 domestic electricity customers must offer a SEG tariff and cannot opt out. Smaller suppliers can join if they want to. Any rate they offer must be above zero.

However, the rate and the terms are up to each supplier. GOV.UK says they are free to set both, which is why prices vary so much. We do not quote a typical rate here, because tariffs change often and any figure would date quickly.

Who can claim

You need three things to claim SEG payments, and each one has a catch.

• MCS certification. You must show that both the installer and the installation are certified under MCS or an equivalent scheme. Our guide to MCS-certified solar installers explains how to check.
• An export meter. You need a meter that can give half-hourly export readings. In practice, that usually means a smart meter.
• A supplier tariff. You apply directly to the supplier you choose. Ofgem keeps a list of suppliers that offer SEG tariffs.

The scheme covers solar PV up to 5 MW, so every home system is well inside the limit. Since a typical house roof holds only a few kilowatts, size is never the barrier.

Because of the MCS rule, an uncertified installer rules you out, even if the panels work perfectly. Check certification before you sign anything.

How to compare tariffs

Do not pick a tariff by the headline rate alone, since other terms can matter more. Look at these points as well.

1. Fixed or variable. A fixed rate gives certainty for a set period. A variable rate can rise or fall, and the supplier may change it.
2. Import requirement. Check whether the tariff expects you to buy your imported power from the same supplier. This affects your whole energy bill.
3. Smart or time-based rates. Some tariffs may pay different rates at different times of day. This could suit you if you have a battery, because you can export in the evening.
4. Payment terms. Check how often you are paid and whether there is a minimum balance.
5. Contract length and exit. Find out whether you can switch if a better rate appears.

Because you can change suppliers, your first choice does not lock you in. Review your tariff once a year, as you would your normal energy tariff.

Why export pays less than saving

The most valuable unit of solar power is the one you use yourself, because it replaces power you would have bought. Ofgem’s price cap from October to December 2026 averages 26.32p per kWh for electricity. Export rates are set separately by each supplier, and they are usually lower than the price you pay to import.

That gap matters when you plan your system. Where you can, use power by day, for example by running a dishwasher while the sun is out. A battery moves more of your own power to the evening. Our guide asks are solar batteries worth it and looks at that trade-off.

Common mistakes to avoid

Many people assume SEG starts the day the panels go on. In fact, you must have the right meter and a signed-up tariff first. Ask your installer and your supplier which meter you need before the work begins.

Others pick the highest rate and never look again. Rates can change, so a tariff that was best last year may not be best now. Set a yearly reminder to compare.

Finally, do not size a system only to export. Exported power earns less than power you use at home. Size for your own use first, and treat export as a bonus.

What you need before you export

SEG only pays once the system is connected legally, so the paperwork comes first. Before you send power to the grid, your installer must notify your network operator. The rules depend on the size of your system, and our G98 and G99 guide covers them. Some roofs may also need consent, so see whether solar panels need planning permission at your address.

Costs also affect the payback, and the current VAT rate helps. Installation of solar panels and batteries is currently zero-rated for VAT. Our post on VAT on solar panels explains when that ends.

How much could you export?

Your export depends on your roof, your system size and when you are at home. A home that is empty all day exports more than one with someone in.

The yield for your area also matters. In PVGIS modelling, a 4 kWp system in London makes around 4,080 kWh a year. However, your own use decides how much goes to the grid.

Read about how solar performs in London for the local figures. Yields differ by town, so also see how solar installers serving Bristol quote for similar roofs.

Ask your installer to estimate how much of your output you would use and how much you would export. A good quote shows both numbers and states its assumptions, so you can test them against your own habits.

Next steps

Start by choosing an MCS-certified installer, because SEG depends on it. Our page on solar panel installation explains what to expect. If you are thinking about storage, read about solar battery storage as well.

When you are ready, you can request quotes through our enquiry form. Your enquiry goes into a central dashboard, because nobody is contacted automatically.