Can my business sell surplus solar to the grid?
Yes. Under the Smart Export Guarantee, larger electricity suppliers must offer to pay you for low-carbon electricity you export. Solar up to 5MW qualifies if properly certified. The supplier sets the rate, which must be above zero, and pays based on export meter readings.
If your solar panels make more power than the building uses at that moment, the surplus flows out to the grid. The Smart Export Guarantee (SEG) is the scheme that makes suppliers pay for it. It started on 1 January 2020 and applies in Great Britain.
Who qualifies
- Solar PV, onshore wind, hydro and anaerobic digestion up to 5MW.
- Micro combined heat and power up to 50kW.
- Anyone with an eligible installation in Great Britain who meets the scheme criteria, including businesses.
- Certification: for solar PV, wind and micro-CHP up to 50kW, both the installation and the installer must be certified, for example through MCS or an equivalent scheme. Larger solar (over 50kW up to 5MW) needs the installation certified, not the installer.
- You cannot be paid SEG and Feed-in Tariff export payments for the same installation.
How you get paid
Each SEG licensee chooses its own tariff, contract length and terms. The rate must be above zero, but beyond that it varies, so compare. Payment is based on export readings, so Ofgem's generator guidance says you need a meter that measures export half-hourly and an export MPAN, which is a separate 13-digit number from your import MPAN. An existing smart meter may already do this; ask the SEG supplier to confirm. They do not have to pay until they can get your export readings.
You don't have to export to your own supplier. Suppliers with at least 150,000 domestic electricity customers must offer an SEG tariff, and smaller ones can choose to. Ofgem publishes the list, and you can only be paid by one SEG supplier at a time.
Worked example
Suppose a workshop exports 8,000 kWh in a year and the chosen tariff pays 8p/kWh (an assumed figure for illustration, not a quoted rate).
8,000 kWh x £0.08 = £640 a year.
Compare that with using the power yourself: at an import price of, say, 26p/kWh, each kWh used on site saves far more than a kWh sold. That is why most business solar is sized to the daytime load rather than to export.
Tax
Record export payments in your accounts and ask your accountant how they should be treated for your business. We have not covered the tax rules here.
Practical steps
- Confirm with your installer that your system is eligible.
- Check which suppliers offer SEG tariffs on Ofgem's list.
- Compare rates, contract lengths and payment frequency.
- Apply to the chosen supplier and provide your meter details.
Read more at SEG for business and see how payback works in solar payback.
Choosing between tariffs
| Check | Why it matters |
|---|---|
| Rate per kWh | Must be above zero, but varies widely |
| Fixed or variable | A variable rate can fall |
| Contract length | Locks you in or lets you move |
| Payment frequency | Monthly versus annual affects cash flow |
| Meter reading method | Needs smart or export-capable metering |
Selling versus using
With a typical import price in the mid-20s pence per kWh and an export rate far lower, using your own power is usually worth more. If your building is empty at weekends, a battery can store daytime surplus; see business battery storage.
Larger or older systems
If your array is over 5MW, or you are on the older Feed-in Tariff, the rules differ. See Feed-in Tariff. Ofgem's page says suppliers set the terms, so always read them before applying.
Before you apply: paperwork checklist
- Your MCS (or equivalent) certificate, if the system is 50kW or under.
- The export MPAN, which your supplier or network operator can confirm.
- Proof of ownership or your lease, if the supplier asks.
- Bank details for payments.
Sources
General information only. Energy prices, rules and supplier terms change; check the latest position with your supplier, Ofgem or the Energy Ombudsman before you act.