Solar export tariffs explained: how much you're paid for spare solar electricity, and why it matters more than your panels

If you have solar panels, or you're thinking about getting them, the rate you're paid for spare electricity can make a bigger difference to your savings than which panels you buy. Yet most people never look at it.

Here's what it is, in plain English, and how much difference it can make for a North West home.

In plain English: what's an "export tariff"?

On a sunny day your panels often make more electricity than your home is using at that moment. That spare electricity flows out of your house into the grid, which the industry calls "exporting" it.

Your energy supplier pays you for it. The rate they pay, in pence for each unit of electricity, is called an "export tariff". Think of it as a buy-back rate for your spare solar power.

Since 2020, larger energy suppliers have had to offer at least one buy-back rate, under a government scheme called the Smart Export Guarantee (SEG). The rules only say the rate must be more than zero, so rates vary hugely.

To be paid, you usually need:

• panels fitted by an MCS-certified installer (the industry's approved-installer scheme, which any reputable installer belongs to)
• a smart meter that can record the electricity you send back

A "unit" of electricity is a kilowatt-hour (kWh), the same unit you see on your bill.

Standard vs "premium" buy-back rates

Rates change regularly. Octopus's Outgoing rate, for example, was 15p until March 2026 and is now 12p. Always check the supplier's current terms before switching.

How much difference does it make?

Take a typical 4kW system (about 10 panels) on a North West roof facing south-east or south-west, without a battery:

• it makes about 3,600 units of electricity a year
• a typical home uses about 40% of that itself (about 1,440 units), saving about £379 on bills
• the other 2,160 units are spare and go back to the grid

What that spare electricity earns you depends entirely on your buy-back rate:

Moving from a 4p rate to a 15p one could cut around five years off the time it takes your panels to pay for themselves, with exactly the same panels. That's why we call it the biggest single lever.

The catch: look at the whole deal, not just the buy-back rate

The best buy-back rates usually mean you also have to buy your electricity from that supplier. So:

• Check what you'll pay for electricity too. A great buy-back rate isn't worth it if you end up paying more for the electricity you buy. Roughly work out your yearly cost for both.
• Check whether the rate is fixed, and for how long. Some are fixed for 12 months, while others can change at any time.
• Check the conditions, such as having to buy your panels or battery through that supplier, or limits on system size.
• Some tariffs pay different rates at different times of day. For example, Octopus Flux pays more for electricity you send back in the late afternoon and evening, when demand is highest. These suit homes with a battery, which can store solar power and send it back when the rate is highest.

What about batteries?

With a battery you send less back to the grid, because you store more of your own solar power to use later. So a high buy-back rate matters a little less, unless you're on a tariff that pays more at certain times of day, where a battery lets you send power back when it's worth most.

What about plug-in solar?

Plug-in kits (which you're allowed to fit yourself since 27/08/2026) can't currently be paid under the Smart Export Guarantee, because DIY installs aren't fitted by an approved installer. Some suppliers, including Octopus, have started offering buy-back options for plug-in kits, but in most cases plan to use the power yourself rather than count on being paid for it. See our guide: Plug-in solar vs rooftop solar in the North West.

The bottom line

• If you have solar panels, or are getting them, check your buy-back rate today. Many people are still on 3–4p without realising it.
• A premium rate (12–25p) can cut several years off your payback, but compare the whole package, including what you pay for electricity.
• Rates change, so check yours every year.

Want to see the difference for your home?

Tell us your postcode and roughly what you pay for energy, and we'll email you an independent estimate within 24 hours, showing how long your panels would take to pay for themselves on a standard and a premium buy-back rate. No phone number needed, and no sales calls.