Smart Export Guarantee: How Much Can You Earn Selling Solar Back?

The SEG is a government scheme that requires large energy suppliers (those with 150,000+ customers) to offer a tariff to solar owners who export electricity to the grid. You sell your surplus electricity to your supplier, they pay you at a rate they set.

Unlike the old Feed-in Tariff, the SEG rate isn't fixed by the government — suppliers compete, and rates vary. The SEG is not optional for large suppliers: they are legally required to offer it. The rate they offer is up to them.

SEG rates vary significantly by supplier. Here's a comparison of current rates:

How much you actually earn depends on how much you export. Here's a worked example:

• System: 8 panels (3.72 kWp), no battery — typical export rate around 55% of generation
• Annual generation: ~3,150 kWh
• Annual export: ~1,730 kWh (55%)
• At 7p/kWh (Octopus): ~£121/year
• At 12p/kWh (British Gas): ~£208/year
• At 15p/kWh (E.ON Next): ~£260/year

Adding a battery significantly reduces your export — which means less SEG income but much greater bill savings through self-consumption. The net result is almost always better with a battery:

To register for SEG, your installation must have a valid MCS certificate. There are no exceptions. A non-MCS install cannot earn SEG payments — and it cannot be retrospectively certified.

This is worth emphasising: the savings from SEG payments over 25 years can easily amount to £2,000–£5,000. An installer who offers to skip MCS certification to save upfront cost is asking you to forfeit that — plus your grant eligibility — in exchange for a modest saving.

Registration is straightforward:

• Step 1: Receive your MCS installation certificate from your installer
• Step 2: Compare SEG rates at ofgem.gov.uk or a comparison site
• Step 3: Apply to your chosen supplier — most have an online application form
• Step 4: Supplier installs or confirms your smart meter can record export data
• Step 5: Start receiving payments — typically quarterly, directly to your bank account

We help every customer through this process as part of the installation service. You don't need to figure it out alone.

The key insight is that SEG income and bill savings trade off against each other. To maximise SEG income, you'd export as much as possible — but that means buying expensive grid electricity in the evening instead of using stored solar. The financially optimal approach is to maximise self-consumption first, then earn from whatever's left over.

The Levelise Hub monitors SEG rates in real time and can adjust when your battery exports — for example, holding charge to export during a high-rate period rather than at a low-rate time. Over the course of a year, this optimisation adds up.