What you actually get paid for exported solar power
The Smart Export Guarantee pays you for electricity you send to the grid, at a rate your supplier sets — currently between about 3p and 15p per kWh. That fivefold spread matters more than almost any equipment decision, because a typical UK system exports most of what it makes.
Why this matters more in Britain than in America
A typical UK household uses about 2,500 kWh of electricity a year. A normal 4 kW array in a median UK location produces roughly 3,376 kWh. That is more than the whole house consumes — so a large share of it is exported, and what you are paid for those exported units drives your payback.
In the US the equivalent question barely arises, because a typical home there uses over four times as much electricity and consumes most of what it generates.
The rule that can disqualify you completely
The spread is the story
Published SEG rates run from about 3p to 15p per kWh. The best widely available rate for a system without a battery is around 13p, and several major suppliers offer 12–15p. Some battery-specific tariffs pay far more during peak evening windows. Switching supplier costs nothing and needs no new hardware, which makes it the cheapest possible improvement to your numbers.
Our figures throughout this site assume a deliberately conservative 12p. If you are on 3p, your real payback is worse than we show. If you are on 15p, it is better.
What that looks like across the UK
Same hardware, same export rate — the only variable here is measured sunlight.
| City | Sun hrs | 4 kW output | Payback |
|---|---|---|---|
| Penzance | 1,186 | 4,032 | 10.3 yrs |
| Hastings | 1,148 | 3,903 | 10.5 yrs |
| Truro | 1,144 | 3,890 | 10.6 yrs |
| Brighton and Hove | 1,132 | 3,849 | 10.7 yrs |
| Isle of Wight | 1,121 | 3,811 | 10.7 yrs |
| Poole | 1,120 | 3,808 | 10.7 yrs |
Sunlight figures are our own measurements: the median of roughly 16 suburban rooftop samples per city from Google's Solar API, across 115 UK cities. Electricity price is the Ofgem default tariff cap unit rate, 26.11p/kWh, for 1 July – 30 September 2026 — the cap is reset on 1 October 2026 and will be restated excluding VAT, so this figure has a known expiry. Household usage is Ofgem's Typical Domestic Consumption Value of 2,500 kWh, revised down on 1 July 2026. Export is modelled at a conservative 12p/kWh. Estimates only — not a quote, and not financial advice.
Check a specific UK city
Frequently asked
How much does the Smart Export Guarantee pay?
Between about 3p and 15p per kWh, set by your supplier rather than by the government — the scheme obliges larger suppliers to offer something, but not to offer a good rate. The best widely available rate without a battery is around 13p. Switching tariff is the cheapest way to improve a UK solar return.
Do I need an MCS certified installer for SEG?
Yes, and this disqualifies people every year. Both the installation and the products must be MCS certified, and you need a smart meter that can send half-hourly readings. Without certification you cannot claim SEG at all, which removes the export half of your return permanently.
Is SEG the same as the old Feed-in Tariff?
No. The Feed-in Tariff closed to new applicants in 2019 and paid for generation as well as export, often at far higher rates. SEG pays only for what you actually export, and the rate is set by each supplier competitively rather than fixed by government, so shopping around genuinely matters.