SEG earnings calculator
Every unit of solar you don’t use can be sold back to the grid under the Smart Export Guarantee. Enter your system size and tariff for your estimated annual export income.
Figures checked October 2026 Estimate
You need an MCS certificate for the installation and a smart meter that records export. Payments are usually quarterly or biannual, depending on supplier.
SEG rates in October 2026
The Smart Export Guarantee obliges larger suppliers to pay for exported solar, but each sets its own rate — and the spread is wide. Standalone export tariffs (where you import from someone else) paid an estimated 3–6p/kWh in October 2026; tie your import to the same supplier and export rates of 12–16p/kWh appear, because the supplier is really paying to keep your custom.
| Supplier (standalone export) | Rate (Oct 2026) |
|---|---|
| E.ON Next | 6.0p/kWh |
| ScottishPower | 6.0p/kWh |
| So Energy | 4.5p/kWh |
| Octopus Energy | 4.1p/kWh |
| OVO Energy | 4.0p/kWh |
| British Gas | 3.0p/kWh |
Rates checked October 2026; suppliers change them, and the best combined deals require your import tariff too — compare the pair, not the export rate alone.
How much will you actually export?
A 4kWp system generates an estimated 3,400kWh a year. A household out during the day typically exports ~60% without a battery — about 2,000kWh, worth an estimated £100/yr at 5p, or ~£300 at a 15p combined rate. With a battery, exports drop toward 25% but each unit kept displaces a 26.32p purchase, so total value rises even as SEG income falls. That trade-off is why this page exists separately from the savings estimator: SEG is the smaller, second income — never size a system to maximise it.
SEG questions
What do I need to claim SEG?
An MCS certificate for your installation (your installer provides it), an export-capable smart meter, and an application to the supplier of your choice — you don’t have to use your import supplier, though the better rates usually require it.
Can I switch SEG supplier?
Yes, in much the same way you switch import tariffs. Watch for combined deals: a 15p export rate paired with an expensive import tariff can be worse than 5p paired with a cheap one.
Is SEG income taxable?
For typical domestic systems generating for your own home, SEG income is generally not treated as taxable income. If you’re generating commercially or at large scale, take advice — this page doesn’t give tax advice.
Ready for real prices?
Calculators give you the ballpark. Get free, no-obligation quotes from MCS-certified UK installers and compare them against these numbers.