Fit solar panels and there will be hours, plenty of them in summer, when your roof makes more electricity than the house can use. That surplus does not vanish; it flows back out through your meter to the grid, and the Smart Export Guarantee is the scheme that pays you for it. It replaced the old Feed-in Tariff for new installations and works on a simple principle: licensed suppliers must offer solar owners a price for every kWh they export. The detail is where it gets interesting, because the rate you are offered, and how much you actually export rather than use yourself, decide whether export is a useful top-up or an afterthought. This guide explains how the SEG pays, what you need to claim it, and why the smarter move is usually to use your own power before it ever reaches the meter.
The short answer. The Smart Export Guarantee (SEG) requires larger electricity suppliers to pay you for surplus solar electricity you export to the grid. You need a smart meter that records export and an eligible, certified solar installation. Rates are set by each supplier and vary widely, from a couple of pence per kWh up to mid-teens or more on the best tariffs, sometimes fixed and sometimes tracking wholesale prices. A typical home might export 1,500 to 2,500 kWh a year, so SEG income often runs from under £100 to a few hundred pounds. Using your own solar directly is worth far more than exporting it, so self-consumption comes first.
What the SEG is, and what it replaced
The Smart Export Guarantee launched at the start of 2020 to replace the Feed-in Tariff, which had closed to new applicants the year before. Under the rules, every electricity supplier above a certain size must offer at least one tariff that pays small generators, such as domestic solar owners, for the electricity they send to the grid. The rate has to be greater than zero, but beyond that the government does not set it; each supplier picks its own. Smaller suppliers can offer an export tariff voluntarily.
The important difference from the old Feed-in Tariff is what gets paid for. The Feed-in Tariff paid a generous, government-backed rate for everything you generated, whether you used it or exported it, and those payments were guaranteed for years. The SEG pays only for what you actually export, at a rate the supplier can change. So the headline support is leaner, and the value now depends much more on your own behaviour and on shopping around for a good export deal. If you have older panels still on a Feed-in Tariff agreement, you stay on that; the SEG is for systems registered since the Feed-in Tariff closed.
The SEG covers more than rooftop solar: small wind, hydro, anaerobic digestion and micro combined heat and power can qualify too, up to a capacity limit. For the vast majority of households, though, this is a solar story, and the rest of this guide treats it as one. If you are still deciding whether to fit panels at all, start with solar panels: the basics and whether solar is worth it.
How you actually get paid
Three things have to be in place before export payments can flow. First, your solar installation needs to be certified under the Microgeneration Certification Scheme (MCS), or an equivalent, which a reputable installer arranges as part of the job and documents with a certificate. Second, you need a smart or other meter capable of recording how much you export, taking readings at least every half hour; most homes already have a suitable smart meter, and if yours does not record export you may need it reconfigured or replaced. Third, you apply to an SEG supplier, which does not have to be the same company that sells you your electricity.
That last point is worth dwelling on. Your import supplier (who you buy electricity from) and your export supplier (who pays your SEG) can be two different companies. In practice many people choose a single supplier for both because some firms offer their best export rates only to their own import customers, and a paired deal can be simpler to manage. But you are free to split them if the numbers favour it.
Once you are signed up, the supplier reads your export figure remotely and pays you, typically quarterly, either as a credit against your bill or as a payment. There is no separate meter reading for you to send for export; the smart meter handles it. Your job is mostly the initial paperwork and then keeping an eye on whether your export rate is still competitive, because suppliers add, withdraw and change these tariffs over time.
What sets the export rate
This is where SEG tariffs diverge sharply, and it pays to understand the two broad types on offer:
- Fixed-rate SEG pays a flat price per exported kWh, the same at any time of day. It is predictable and easy to plan around. Rates vary enormously between suppliers, so the gap between a poor fixed tariff and a strong one can be several pence per kWh, which on a couple of thousand exported kWh a year is real money.
- Variable or smart SEG ties the export price to wholesale electricity prices, so it changes through the day and can spike when grid demand is high. These can pay more per kWh on average, sometimes much more during evening peaks, but they reward you for exporting at the right times, which usually means pairing the panels with a battery so you can hold power back and release it when the price is highest.
A few other factors move the rate you are offered. Some of the highest export prices are bundled with import tariffs as a package, so the best export deal might be tied to a particular time-of-use import tariff; whether that combination suits you depends on your whole usage pattern, which is the kind of trade-off our guide to time-of-use tariffs unpicks. Because the figures change so often, this guide deliberately does not quote a league table of current rates; check live offers when you apply, and compare the export rate alongside the import rate rather than in isolation.
A worked example: what export is worth
Take a common setup: a 4 kWp rooftop system in the south of England, generating roughly 3,800 kWh a year. How that splits between what you use and what you export depends entirely on when you use electricity. Suppose, with no battery and a typical daytime-light, evening-heavy household, you manage to use 40 per cent of your generation directly and export the other 60 per cent. That is about 1,520 kWh used at home and 2,280 kWh exported.
Now value each part at illustrative rates:
| Where the solar goes | Amount | Valued at | Annual value |
|---|---|---|---|
| Used at home (avoids buying import) | 1,520 kWh | 26p per kWh saved | £395 |
| Exported under SEG | 2,280 kWh | 5p per kWh (modest tariff) | £114 |
| Exported under SEG | 2,280 kWh | 15p per kWh (strong tariff) | £342 |
Illustrative figures to show the method, not current prices. Import value uses an example 26p per kWh; export values use example SEG rates. Your generation, split and rates will differ.
Two lessons jump out. First, a good export rate is worth roughly three times a poor one on the same panels, so the choice of SEG tariff matters a lot. Second, and this is the part people miss, the electricity you use yourself is worth far more per kWh than the electricity you export, because using it avoids buying a unit at the full import price (around 26p in this example) while exporting only earns the SEG rate. That gap is the single most important idea in domestic solar economics.
Why self-consumption beats export
Follow the logic of the example. Every kWh you use in the house saves you the full import price. Every kWh you export earns only the SEG rate, which is usually well below the import price. So shifting one kWh from the export column to the self-use column is worth the difference between the two, which in the example above is roughly 26p minus 5p, or 21p per kWh. Do that with a few hundred kWh a year and you have outperformed the choice of export tariff entirely.
Practical ways to lift self-consumption without spending anything:
- Run the big loads in daylight. Put the dishwasher, washing machine and tumble dryer on while the sun is up, using their delay timers if you are out, rather than in the evening.
- Time-shift the flexible stuff. Charge an EV, run a pool or pond pump, or heat the water during the sunniest part of the day.
- Pre-heat or pre-cool around midday. On a sunny day, nudging the home or the hot water while the panels are producing means less paid-for energy later.
Even with good habits, a roof often makes its biggest surplus at midday when nobody is home, which is exactly the gap that storage is designed to fill. You can also use a diverter to soak surplus into hot water; our guide to the solar diverter covers that cheap, popular option.
How batteries and diverters change the maths
A home battery stores your midday surplus and lets you use it in the evening instead of exporting it cheaply and buying it back expensively after dark. In the example above, a battery might convert a big slice of that 2,280 exported kWh into self-used kWh worth 26p each rather than the SEG rate. That can transform the economics, though batteries cost several thousand pounds, so the saving has to be weighed against the outlay over the unit's life; we work through that sum in battery storage payback and the wider picture in solar battery storage.
Batteries also unlock the clever version of SEG. On a smart, wholesale-linked export tariff, a battery lets you hold power back and export it during the evening peak when the export price is at its highest, rather than dumping it to the grid at midday when both demand and the price are low. Some households even charge a battery from cheap overnight import electricity and export it at peak, though whether that is allowed and worthwhile depends on the specific tariff terms.
A diverter is the budget cousin of a battery. Instead of storing surplus in a cell, it sends it to your immersion heater, turning spare solar into a tank of hot water for nothing. It will not power your evening television, but for a modest one-off cost it stops a chunk of summer surplus leaking out at the low export rate, and it suits homes with a hot water cylinder particularly well.
How to apply, and what to watch
The route to getting paid is short once the panels are in:
- Get your MCS certificate. Keep the documentation your installer gives you; suppliers ask for it when you apply for an SEG tariff.
- Check your meter records export. A smart meter that measures import and export both ways is what you need. If yours does not, ask your supplier about reconfiguring or upgrading it.
- Choose an SEG supplier. Compare export tariffs across suppliers, not just your own, and weigh fixed against smart options based on whether you have storage and flexible usage. Look at the export and import rates together if they come as a package.
- Apply and submit your details. Once accepted, payments arrive as bill credit or cash, usually each quarter, with no export readings for you to send.
- Review it yearly. Export tariffs change. The deal that was competitive when you signed up may have been overtaken, and switching your export supplier is allowed.
A couple of watch-outs. The SEG is not the same as the closed Feed-in Tariff, so do not expect the old guaranteed, generation-based payments. And the rate is not a magic number to chase in isolation: a headline export price tied to an expensive import tariff can cost you more on the units you buy than it earns on the units you sell. Always look at the whole deal.
The bottom line
The Smart Export Guarantee turns your surplus solar into income, but it is the junior partner in solar economics. You need a certified installation and a meter that records export, then you pick an SEG supplier, which can differ from your import supplier, and the money arrives quarterly with no readings to send. Export rates vary so widely that a strong tariff can be worth several times a weak one, so it is worth comparing and reviewing yearly. The bigger prize, though, is using your own generation: every kWh you consume at home avoids the full import price, while every exported kWh earns only the lower SEG rate. Shift loads into daylight, consider a diverter for hot water or a battery for the evenings, and treat export as the useful extra it is rather than the main event. To price the appliances you might shift into your sunniest hours, use the running-cost calculator.