Short answer: in Great Britain you are paid for exported electricity through a Smart Export Guarantee (SEG) tariff. That needs MCS-certified (or equivalent) solar and an export-capable smart meter. As of 25 October 2026, Outgoing Octopus pays a flat 12p/kWh. Agile Outgoing pays half-hourly prices that averaged 11.6p in London over the last year, but only about 10.6p for typical solar exports. Flux export pays 30.3p from 16:00 to 19:00 in London. Only Flux pays for electricity exported from a battery, and plug-in solar gets nothing.
Which is best depends on whether you have a battery. This guide compares them with Fortyeight’s model.
The Smart Export Guarantee in brief
Ofgem’s SEG started on 1 January 2020. Larger suppliers that Ofgem designates as SEG licensees must offer at least one export tariff to eligible generators. The rules are short:
- Eligible technologies: solar PV, wind, hydro and anaerobic digestion up to 5 MW, and micro-CHP up to 50 kW, in Great Britain.
- Certification: solar, wind and micro-CHP up to 50 kW need MCS or equivalent certification.
- Rate: set by each supplier, but SEG tariffs “must always be above zero”.
- Metering: payment is based on actual export meter readings, which in practice means a smart meter set up to record export.
SEG sets a floor, not a price. The government does not set rates, so they vary between suppliers and over time. Compare the terms as well as the pence per kWh.
The three Octopus export tariffs
Fortyeight models Octopus because its tariffs are published in a public API, region by region. Fortyeight is not affiliated with Octopus. Prices below are as fetched on 25 October 2026 and carry no VAT, because export prices have none.
| Tariff | How it pays | London rate | Pays for battery exports? | Needs |
|---|---|---|---|---|
| Outgoing Octopus | Flat | 12p/kWh (since 1 Mar 2026) | No | MCS (or the £250 route) |
| Agile Outgoing | Half-hourly, wholesale-linked | Averaged 11.6p (Oct 2025 – Oct 2026) | No | MCS (or the £250 route) |
| Flux export | Three time bands | 30.3p peak, 11.1p day, 4.7p night | Yes | Solar + battery + MCS, and Flux import |
Outgoing Octopus
A flat 12p/kWh for every exported kWh, in every region, since 1 March 2026. It is simple and predictable. It suits most solar homes without a battery, because their exports come at midday when time-varying prices are low.
Agile Outgoing
Agile Outgoing follows the wholesale market half-hour by half-hour, with prices set the day before. Over the 12 months to 24 October 2026, Octopus’s published London prices averaged:
| London, Oct 2025 – Oct 2026 | Agile Outgoing |
|---|---|
| All half-hours | 11.6p |
| 16:00–19:00 | 18.6p |
| 10:00–16:00 | 9.4p |
| 02:00–05:00 | 9.7p |
| Highest half-hour | 42.3p |
| Lowest half-hour | 0.0p |
The average looks close to Outgoing’s 12p, but solar exports land in the cheap midday hours. In Fortyeight’s model a south-facing system’s exports earned an average of 10.6p/kWh on Agile Outgoing, compared with 12p on Outgoing. Agile Outgoing only wins if your exports fall in expensive half-hours, and plain solar cannot arrange that. A battery cannot help on this tariff either: Octopus’s Outgoing and Agile Outgoing terms exclude payment for exports “not generated by an eligible generation asset, including… batteries”. On Octopus, Flux is the only route to paid evening exports from a battery. Averages in other regions were similar: 11.5p in Eastern England and 11.1p in South and Central Scotland.
Flux export
Flux is a matched pair. Flux import and Flux export are taken together, and you need solar, a home battery and an MCS certificate. Both use the same three bands, 02:00–05:00 cheap, 16:00–19:00 peak, and day rate at other times:
| Region | Export 02:00–05:00 | Export day | Export 16:00–19:00 |
|---|---|---|---|
| London | 4.7p | 11.1p | 30.3p |
| Eastern England | 4.7p | 11.1p | 30.3p |
| East Midlands | 4.5p | 10.6p | 28.9p |
| Merseyside and North Wales | 4.9p | 11.6p | 31.8p |
| South and Central Scotland | 4.6p | 10.9p | 29.8p |
London’s Flux import is 17.0p at night, 28.1p in the day and 39.3p at peak, including 5% VAT. Flux’s point is that battery exports are paid: charge at night or from solar, then sell at 30.3p from 16:00 to 19:00. Intelligent Octopus Flux, the automated version, was shown as unavailable or limited to Octopus-installed systems when we checked.
What each tariff earns: a worked example
Fortyeight’s model takes a typical London household (2,500 kWh a year, Elexon Profile Class 1 load shape) with 4 kWp of solar facing south at 35° (4,076 kWh a year, PVGIS 5.3) and a 3.68 kW inverter. It runs every half-hour of a year on Octopus prices as fetched on 25 October 2026, with 12 months of Agile prices.
Without a battery (3,015 kWh exported):
| Plan | Export income | Average per exported kWh | Net annual bill |
|---|---|---|---|
| Flexible + Outgoing | £362 | 12.0p | £199 |
| Flexible + Agile Outgoing | £319 | 10.6p | £242 |
| Agile + Outgoing | £362 | 12.0p | £114 |
| Agile + Agile Outgoing | £319 | 10.6p | £157 |
Without a battery, the flat 12p beats Agile Outgoing by about £43 a year here. The bigger lever is the import tariff.
With a 10 kWh battery (9.5 kWh usable, 5 kW, 90% round trip):
| Plan | Exported | Export income | Net annual bill |
|---|---|---|---|
| Flexible + Outgoing | 1,875 kWh | £225 | £49 |
| Agile + Outgoing | 2,471 kWh | £297 | −£46 |
| Agile + Agile Outgoing | 2,349 kWh | £251 | −£13 |
| Flux import + Flux export | 3,825 kWh (about 3,030 from the battery) | £1,076 | −£375 |
On Flux the model charges the battery overnight and from solar, then exports about 8 kWh on most evenings at the peak rate. That is worth about £330 a year more than the best Outgoing option here. The modelled result assumes Flux keeps paying for battery-sourced peak exports, the battery cycles almost daily, and your DNO connection does not cap exports. A G99 export limit, battery wear and future price changes would all cut it. It is a model output, not a promise. Our guide to the best Octopus tariff for a battery compares Flux against Agile and the EV tariffs, and the calculator runs it on your own data.
No MCS certificate?
Octopus has a non-MCS route for Outgoing and Agile Outgoing. It costs £250 and needs an Electrical Installation Certificate, a Building Regulations certificate (not needed in Scotland) and an acceptance letter from your DNO. It suits professionally installed systems that were never MCS-registered, not DIY kits.
Plug-in solar: no export payment
Plug-in (balcony) solar, legal in Great Britain since 27 August 2026, is not MCS-certified generation, so in practice it gets no SEG or Outgoing payments. Anything it exports earns nothing. That is why Fortyeight values plug-in solar only by what the home uses as it is generated: about £133 a year for an 800 W south-facing balcony kit in London on Flexible Octopus. See plug-in solar UK rules.
How to choose
- Solar, no battery: a flat rate (Outgoing at 12p) usually beats Agile Outgoing. Check other suppliers’ SEG rates and terms too.
- Solar and battery: model Flux. Paid battery exports change the answer, so check your DNO export limit first.
- Battery, no solar: no Octopus export tariff pays you, because Flux needs solar. The saving comes from import shifting only. See a home battery without solar.
- Plug-in solar: no export income. Size for daytime use.
Tariff prices are as published on 25 October 2026 and change. Check the current terms before switching.