Every unit of solar electricity you generate but do not use gets exported to the grid — and under the Smart Export Guarantee (SEG), a licensed supplier has to pay you for it. What they pay varies by a factor of ten, and most households simply take whatever their existing supplier offers.
How SEG works
- All large electricity suppliers must offer at least one SEG export tariff.
- You are paid per kWh exported, measured by your smart meter.
- Rates are set by each supplier, not by the government. There is no fixed national rate.
- Your export supplier does not have to be your import supplier. This is the single most valuable fact in this article.
What a good rate looks like
Rates broadly fall into three bands:
| Band | Typical rate | Notes |
|---|---|---|
| Poor | 1p - 4p per kWh | Common default offers; usually not worth staying on |
| Reasonable | 5p - 12p per kWh | Competitive fixed rates from most major suppliers |
| High / variable | 15p+ at peak | Wholesale-tracking tariffs; pay far more at peak times, sometimes near zero at midday |
A 4 kWp system typically exports 1,800-2,400 kWh a year. The difference between a 3p rate and a 12p rate on that volume is roughly £160-£220 a year — every year, for the life of the system, for the cost of one switch.
Eligibility
To claim SEG you need:
- A system of 5 MW or less (all domestic installs qualify comfortably)
- MCS certification for the installation — get the MCS certificate from your installer and keep it
- A smart meter capable of half-hourly export readings (SMETS2, or a SMETS1 in smart mode)
- A DNO connection notification, which your installer handles
If your installer is not MCS certified, you cannot claim SEG. That alone rules out most "too good to be true" quotes.
Fixed versus variable export rates
Fixed rates pay the same per kWh whatever the time of day. Simple, predictable, and the right default for a solar-only system.
Variable / wholesale-linked rates track the market. They pay very well in winter evenings and poorly at sunny midday when everyone is exporting. These suit households with a battery, because you can hold generation back and export at the high-price window instead of dumping it at midday.
Rule of thumb: no battery, take a good fixed rate. With a battery, model the variable option — the upside is real but it takes attention.
How to switch your export supplier
- Get your MCS certificate number and MPAN from your installer or bill.
- Compare current SEG rates across suppliers — they change several times a year.
- Apply directly to the supplier you want as your export provider.
- Provide the MCS certificate, meter details and a photo of the installation if requested.
- Keep your import tariff wherever it is cheapest; the two are independent.
Some suppliers offer a materially better export rate to their own import customers. Check whether the bundled deal beats the best standalone export rate plus your best import rate — often it does not.
A common mistake
People assume the export payment is what makes solar work financially. It is not. Self-consumption — using what you generate — is worth three to five times more per unit than exporting it. Optimise for using your own generation first: run the dishwasher and washing machine at midday, charge the EV in daylight, heat the hot water cylinder on a timer. Then get the best export rate you can for the leftovers.
Read next: are solar panels worth it in the UK and home battery storage costs.