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TariffsChoosing a tariff when you have solar, a battery and an EV
No single tariff gives you all three. Solar wants the highest export rate, the battery wants the widest import to export spread, and the car wants the deepest overnight window. Here is how to work out which one to protect, with the annual numbers behind it.
Updated 4 August 2026 · written by the Clearline guidance team
The short answer
Pick the import tariff around whichever load moves the most kilowatt hours, then take the best export rate that import tariff still lets you keep. For most homes running a battery and an electric car, the car is the bigger single load, so the cheap overnight window wins and the export rate has to fit around it. It flips the other way only when the battery is large and the annual mileage is low.
You get one import tariff, not three
Your supplier sells you a single import contract for the whole house. The charger, the battery and the kettle all sit behind the same meter on the same unit rate. The only tariff you can hold separately is the export one, and even that is often conditional on who supplies your import.
Why the three pull in different directions
- Solar wants the highest export rate you can qualify for, because every unit you do not use yourself is paid at that number.
- A battery wants the widest gap between a cheap import window and an expensive export window, because that spread is what it earns on.
- An electric car wants a long, deep off-peak window, because it has to move a lot of kilowatt hours in a few hours and it does not care what the export rate is.
Those three do not fit inside one tariff. E.ON Next Export Exclusive v3 pays 13p per kWh but excludes customers on time-of-use import tariffs, which is exactly what an EV tariff is. Octopus Flux, the three-rate tariff built for solar and battery homes, requires import and export both to sit with Octopus, which rules out running Intelligent Octopus Go alongside it. And the strongest export rates on the market, 17.5p from E.ON Next, 18p from EDF, up to 20p from OVO and 25p from Good Energy, are all conditional on that supplier having installed or sold you the kit in the first place.
Read the export tariff before you choose the import one
The exclusion clause almost always lives in the export contract, not the import contract. E.ON Next Export Exclusive v3 pays 13p and rules out time-of-use import tariffs. Octopus Flux and Outgoing Octopus both require you to import from Octopus. Choose the import tariff first and you can find the export rate you were counting on is no longer available to you.
Where the money actually is
| The decision | Volume assumed | Either side of it | Gap per year |
|---|---|---|---|
| Export rate: a no-strings 4p against a flat 12p | 3,000 kWh exported | £120 against £360 | £240 |
| Export rate: a flat 12p against an installer-locked 18p | 3,000 kWh exported | £360 against £540 | £180 |
| EV charging: the 26.11p capped average against an 8p off-peak rate | 2,400 kWh charged | £627 against £192 | £435 |
| EV charging: 8p against the cheapest published window at 6.99p | 2,400 kWh charged | £192 against £168 | £24 |
| Export timing: roughly 4.99p overnight export against roughly 29.32p peak export | 10 kWh held for the peak on 200 days | £487 gross | A ceiling, not a forecast |
The 26.11p figure is the Ofgem average capped electricity unit rate for 1 July to 30 September 2026 and varies by region and payment method. The 4.99p and 29.32p figures are two of the three Octopus Flux export rates and are secondary-sourced, because Octopus gates the actual rates behind a postcode. The last row values 10 kWh a day held back for the 4pm to 7pm window instead of exported overnight. It ignores round-trip losses and assumes the household did not need that energy itself, so read it as an upper bound.
Two things fall out of that. The EV window is worth roughly twice what the export rate is worth, so it should usually drive the decision. And the difference between the cheapest EV windows is small, £24 a year between 6.99p and 8p, which is less than the £75 exit fee EDF applies to GoElectric Overnight. Chasing the last penny on the import rate is not where the money sits. The standing charge sits on top of all of it at an Ofgem average of 57.19p a day, around £209 a year, and no tariff choice removes it. Our tariffs guide carries the current rates with the date they were checked, and every county page in our coverage area has a local calculator that runs this against your own usage.
If you want the import and export pairing worked out against your real consumption, roof and charger, the free design call does exactly that, on video, with no obligation.
Get your free quote →Three shapes that work
Battery-led: one supplier, one time-of-use tariff
Take a three-rate tariff that fills the battery cheaply overnight and pays a high rate for exporting into the late afternoon peak. Octopus Flux is the clearest example: import and export both with Octopus, with the battery scheduled manually. Its published export rates run at roughly 29.32p per kWh between 4pm and 7pm against roughly 4.99p between 2am and 5am, so the tariff pays you to hold charge rather than release it overnight. The import rates are postcode-gated and not quoted here. It suits a large battery and modest mileage. It rules out a separate EV tariff, because you only get one import contract.
EV-led: a deep overnight window plus a flat export rate
Take the cheapest whole-home overnight window you qualify for and pair it with a flat export tariff. Intelligent Octopus Go gives a 23:30 to 05:30 cheap window for the whole house from 8p per kWh, plus smart-scheduled charging of up to six hours a day, and Outgoing Octopus pays 12p flat alongside it. E.ON Next Drive Smart is 8p from midnight to 6am on an eligible car and charger, E.ON Next Drive is 9p on any car and any charger, and EDF GoElectric Overnight is 6.99p across seven hours from 11pm. The battery fills in the same window as the car.
Split: keep your import, take an open export rate
If your import tariff is one you cannot or will not move, take an export tariff with no import requirement. Those sit at 3p to 6p: British Gas Export SEG and EDF SEG Export Variable at 3p, OVO SEG at 4p, E.ON Next Flex Export at 6p, with one smaller supplier listing 13p without an import condition on a secondary source. On 3,000 kWh exported, the gap between 4p and 12p is £240 a year, so this shape carries a real price.
Which shape wins comes down to two numbers: how many kilowatt hours a year go into the car, and how much battery capacity you can genuinely free up for peak export rather than for your own evening use. A house putting 4,000 kWh a year through the charger will almost always take the second shape. A house with a large battery, low mileage and a south-facing roof can beat it with the first. The EV charging guide covers matching a charger to a window, and the battery storage guide covers usable capacity and cycling.
Every export rate and the condition attached
| Export tariff | Rate | The condition attached |
|---|---|---|
| Octopus Outgoing (fixed) | 12p flat | Import with Octopus, smart meter. Variable, so it can change with notice. |
| Prime Outgoing Octopus | 16p from 4pm to 7pm, 9p the rest of the day | Import with Octopus, 12-month fixed term. |
| Octopus Flux | Regional three-rate export: roughly 29.32p from 4pm to 7pm, roughly 10.11p through the day and roughly 4.99p from 2am to 5am | Solar plus a home battery, import and export both with Octopus, manual battery scheduling. Import rates are shown only against a postcode. |
| British Gas Export Premium | 12p | British Gas electricity customer, system up to 15kW, paid quarterly. |
| E.ON Next Export Exclusive v3 | 13p | E.ON Next import customer, up to 15kW, time-of-use import tariffs excluded. |
| E.ON Next Export Premium v3 | 17.5p | System installed by E.ON Installation Services from 10 November 2025, up to 15kW. |
| EDF Export 12m | 15p | Existing residential EDF electricity customer. The fixed version is listed for solar PV only. |
| EDF Export Exclusive 12m V3 | 18p | Solar or battery purchased from EDF, enquiry and purchase after 2 March 2026, up to 50kW. |
| OVO SEG Install Exclusive | Up to 20p, or 15p for solar with no battery | OVO installs the system and supplies your electricity, under 30kW. |
| Good Energy Solar Savings Exclusive | 25p, fixed for 12 months | Battery installed through Good Energy, import with Good Energy. |
| The no-strings rates | 3p to 6p | British Gas Export SEG and EDF SEG Export Variable at 3p, OVO SEG at 4p, E.ON Next Flex Export at 6p. No import requirement. |
Clearline is an independent guidance service and does not supply energy. Naming a supplier here records their published rate on the date it was checked. It is not a recommendation, an affiliation, or an offer from us.
Rates checked on 3 August 2026 against supplier pages. Intelligent Octopus Flux has been closed to new customers since April 2026. The 15.1p British Gas export rate still quoted on some comparison sites no longer appears on the British Gas sign-up page, so treat any 15.1p claim as stale. Octopus Flux rates are regional and gated behind a postcode, so the figures above are approximate and secondary-sourced. So Energy's 20p rate runs for 12 months and then drops to 4.5p.
The paperwork sets the timetable
No export tariff starts paying until the metering and the certificates are in place. The Smart Export Guarantee needs an installation in Great Britain, an eligible technology, capacity up to 5MW, and metering that records export every half hour. Suppliers stack their own conditions on top. British Gas asks for an MCS certificate, a Flexi-Orb certificate or equivalent, plus G98 or G99 proof of connection from your network operator, and pays quarterly within 28 days of a reading. Octopus quotes one to four weeks for the network operator to create the export MPAN and roughly two to five weeks for full onboarding. OVO quotes around four weeks and asks for battery schematics where a battery is fitted. Installations are carried out by an MCS-certified installation team for your area, and the certificate they issue is what unlocks the export contract, so build the wait into your plan rather than expecting payment from day one. The solar panels guide covers what the certificate should say.
Before you sign
- Work out the annual kilowatt hours going into the car, the battery and the rest of the house separately. The biggest of the three decides the import tariff.
- Read the eligibility line on the export tariff before you commit to an import tariff, because that is where the exclusions live.
- Check the term. Prime Outgoing Octopus and the E.ON Next export tariffs are 12-month fixed. Outgoing Octopus and several others are variable and can change with notice.
- Weigh exit fees against the saving. EDF GoElectric Overnight carries a £75 exit fee, which is more than three years of the £24 a year gap between 6.99p and 8p on 2,400 kWh.
- Treat installer-locked rates as part of the installation price rather than a separate win. A 20p or 25p rate exists only while you stay with that supplier, and So Energy's 20p falls to 4.5p after 12 months.
- Check whether you are still inside the Feed-in Tariff. FiT export payments cannot be combined with the Smart Export Guarantee, and Octopus blocks switching for anyone who started receiving FiT payments in the last 12 months.
- Watch the October cap. Ofgem publishes the 1 October to 31 December 2026 level by 26 August 2026, and that resets the benchmark every fixed and time-of-use offer gets compared against.
Get the full set checked in one go, import tariff, export tariff, battery schedule and charging window, on a free video design call with no obligation.
Get your free quote →Tariff questions, answered
Can I have a good export rate and an EV tariff at the same time?
Sometimes, but not always with the same supplier. E.ON Next Export Exclusive v3 pays 13p and specifically excludes customers on time-of-use import tariffs, which an EV tariff is. Octopus is more accommodating: Intelligent Octopus Go on the import side and Outgoing Octopus at 12p flat on the export side work together. Octopus Flux does not, because it is itself an import and export tariff and you can only hold one import contract.
Do I have to import from the same supplier to get their export rate?
For the good rates, usually yes. The export tariffs with no import requirement sit at 3p to 6p, which is British Gas Export SEG and EDF SEG Export Variable at 3p, OVO SEG at 4p and E.ON Next Flex Export at 6p. On 3,000 kWh exported a year, staying put on 4p rather than moving to a 12p rate costs about £240 a year, so the split is worth pricing rather than assuming.
Is Octopus Flux better than a flat export rate if I have a battery and an EV?
It depends on the split between the two loads. Flux earns on the spread inside its export rates, roughly 4.99p in the small hours against roughly 29.32p from 4pm to 7pm, which is large, but it takes your only import contract and so blocks a dedicated EV window. If the car is doing thousands of kilowatt hours a year, the 8p whole-home overnight window usually beats the extra export margin. Those Flux figures are regional and postcode-gated, so check yours before deciding.
How long before the export payments actually start?
Allow a few weeks after the system goes live. Octopus quotes one to four weeks for your network operator to create the export MPAN and roughly two to five weeks for full onboarding. OVO quotes around four weeks and wants MCS certification, a smart meter and battery schematics where a battery is fitted. British Gas pays quarterly, within 28 days of a reading.
Does the price cap apply to my EV or export tariff?
The cap sets a maximum on standard variable rates, not on fixed or time-of-use deals, and Ofgem notes that around 40 per cent of accounts sit on fixed tariffs it does not touch. It still matters as a benchmark. For 1 July to 30 September 2026 the average capped electricity unit rate is 26.11p per kWh with a 57.19p daily standing charge, which is the number an 8p overnight rate is being measured against.
I am still on the Feed-in Tariff. Can I move to a better export rate?
Not while you are taking FiT export payments, because they cannot be combined with the Smart Export Guarantee. Octopus also blocks switching export arrangements for customers who began receiving FiT payments in the last 12 months. Worth checking your FiT paperwork first, since deemed export at 50 per cent can still be worth more than a 3p or 4p no-strings SEG rate depending on your generation tariff.
See the numbers next: Tesla Powerwall 3, installed, or export rates compared.
Figures and specifications in this guide are sourced below and were checked on the date shown. Rates and product specifications change; we confirm the current picture on your free design call.
Sources
- Ofgem, energy price cap 1 July to 30 September 2026: average unit rates and standing charges ofgem.gov.uk
- Ofgem, Smart Export Guarantee scheme rules, eligible technologies and metering requirements ofgem.gov.uk
- Octopus Energy, Outgoing Octopus and Prime Outgoing rates, eligibility and onboarding timings octopus.energy
- Octopus Energy, Flux tariff structure and export windows octopus.energy
- Octopus Energy, Intelligent Octopus Go charging window and smart scheduling octopus.energy
- E.ON Next, Smart Export Guarantee tariff table and eligibility conditions eonnext.com
- E.ON Next, Next Drive and Next Drive Smart EV tariff rates and windows eonnext.com
- EDF, smart export tariff rates and GoElectric Overnight terms edfenergy.com
- British Gas, Smart Export Guarantee export tariffs, certification requirements and payment terms britishgas.co.uk
- OVO, Smart Export Guarantee rates and signup requirements ovoenergy.com
- Good Energy, Solar Savings export rates goodenergy.co.uk
- Sunsave, SEG rate roundup, used only where supplier pages gate rates behind a postcode sunsave.energy
Read next
Why tariff choice moves payback more than kit choice
Identical kit, five times the export income. The tariff decision worked through with August 2026 rates.
Read the guide →The price cap explained, and what it does to solar payback
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Read the guide →Does a standalone battery actually pay back?
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Read the guide →