Smart Export Guarantee (SEG) Calculator

The SEG requires licensed UK electricity suppliers with 150,000+ customers to offer a tariff for exported renewable electricity. It replaced the Feed-in Tariff (FiT) for new installations from January 2020. You need an MCS-certified installation and a smart or SMETS2 meter to qualify.

Rates vary by supplier (verified June 2026): British Gas Export & Earn Plus ~15.1p/kWh (import-bundled; structure changing from 6 July 2026), EDF Export and Good Energy ~15p, E.ON Next Export Exclusive ~13p/kWh (cut from 16.5p in November 2025; requires E.ON import bundling — E.ON’s higher 17.5p Next Export Premium is restricted to E.ON-installed solar), Octopus Outgoing Fixed 12p/kWh (cut from 15p on 1 March 2026). Rates change frequently — compare current offers. Some suppliers offer time-of-use rates (e.g. Octopus Agile Outgoing) that pay more during peak hours.

A typical 4 kWp system exporting 60% of 3,800 kWh generates about 2,280 kWh of exports. At Octopus’s current 12p/kWh rate that earns ~£274/year (it was ~£342 at the old 15p); a 15p tariff such as EDF earns ~£342. The real value is in self-consumption: using the other 1,520 kWh saves ~£397/year at the Ofgem cap unit rate for the current quarter (26.11p/kWh, 1 July–30 September 2026).

A battery stores surplus generation for later self-use instead of exporting it, so it actually lowers SEG export income but raises import savings — and each self-used kWh is worth far more (the ~26p you avoid paying vs ~12–15p you earn exporting). This calculator uses an illustrative assumption that a typical battery raises self-consumption by about 25 percentage points (capped at 85%); for example a 40% self-consumption home might rise to roughly 65%. Your actual uplift depends on battery capacity and how you use power, so treat it as a rule of thumb, not a guaranteed figure.

Yes, you need a smart meter (SMETS2) or a meter capable of measuring exports to receive SEG payments. If you have an older meter, your supplier must install a smart meter. Some SEG tariffs use half-hourly export data to pay variable rates based on time of day.