Smart Export Guarantee and a Home Battery: How to Choose a Tariff
- Suppliers set the SEG rate, contract length and other terms, and the rate must stay above zero.
- You need an eligible generator such as solar panels, with an MCS-certified installation.
- A meter that can give half-hourly export readings is needed, typically a smart meter.
- You can choose a SEG supplier that is not your normal energy supplier.
- A battery changes when and how much you export, so compare terms, not only the pence per unit.
A Smart Export Guarantee (SEG) tariff pays you for electricity you send to the grid, and suppliers choose their own terms. With a battery in the house you export less and at different times, so the headline rate matters less than the conditions around it.
What the rules fix, and what they leave to the supplier
Ofgem says the SEG began on 1 January 2020 and that suppliers who are SEG licensees set the rate, the contract length and the other terms. The one floor it states is that any SEG tariff must always stay above zero. Licensees must offer a tariff to all eligible generators, and Ofgem publishes a list of them.
GOV.UK adds that suppliers decide whether a tariff is fixed or variable, and that tariffs can change, so it is worth checking now and then that you are still on a competitive one. That is the core of the choice: the scheme guarantees that you are offered a tariff, not that it is a good one.
What a battery changes
Solar panels send electricity to the grid when the house does not use it. A battery soaks up part of that surplus, so you export less, and mostly later in the day or only once the battery is full. Because of that, a very high rate on a few exported units is worth less than it looks.
GOV.UK says a storage device such as a household battery that can both import and export may also be used, and tells readers to ask the prospective supplier. We would not assume that exports from a battery are paid the same way as exports from panels. Get the answer in writing before you rely on it. Our guide to how a home battery saves money explains why using stored energy yourself often beats exporting it.
Fixed or variable: what to weigh
A fixed rate gives certainty for the length of the contract, which is easier to plan around. A variable rate can rise or fall, so you need to check it from time to time. Some suppliers may also offer rates that differ by time of day, and others tie the export tariff to an import tariff. We did not verify any specific tariff or rate for this guide, so compare current offers yourself.
- Is the rate fixed, and for how long? What happens when that period ends?
- Can the rate change during the contract, and how much notice do you get?
- Do you have to take your electricity from the same supplier?
- Are there exit fees if you move to a better offer?
Good to know
Ofgem advises generators to shop around. You can apply to a SEG licensee that is different from your electricity or gas supplier.
Meter, eligibility and the paperwork
To apply you must show that your installation and installer are certified through MCS or an equivalent scheme. GOV.UK also says you need a meter that can provide half-hourly export readings, typically a smart meter, and that your supplier can arrange one if you do not have it. Ofgem notes that payments are based on actual meter readings.
You cannot receive a SEG tariff if you already receive export payments under the Feed-in Tariffs scheme. Compare tariffs on the same basis, using your own expected export, which you can estimate with the home battery calculator.
Common questions
Can I get a SEG tariff with a battery but no solar panels?
The scheme covers eligible generators such as solar PV. GOV.UK says a household battery can be used alongside a qualifying system, so we would not expect a battery alone to qualify. Ask the supplier.
Does SEG pay for electricity I use myself?
No. GOV.UK says you are paid for each unit you export to the grid, not for what you use at home.
Do I have to use my current supplier for SEG?
No. Ofgem says you can use a SEG licensee that differs from your electricity or gas supplier.
Is there a guaranteed minimum rate?
Ofgem says only that a SEG tariff must stay above zero. Rates, contract lengths and other terms are set by each licensee.
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