Choosing a tariff when you have solar, a battery and an EV

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.

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.

Where the money actually is

The 26.32p figure is the Ofgem average capped electricity unit rate for October to December 2026 and varies by region and payment method. The overnight and peak figures are two of the three Octopus Flux export rates, published by region and checked on 28 October 2026, and the gross range runs from the narrowest to the widest regional gap. 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 54.83p a day, around £200 a year at the October to December 2026 cap, 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.

Three shapes that work

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.

Get my free quote

Three details. We call or text within one working day to book your free 30-minute design call, on video or by phone if you prefer.

Postcode

Please add your full postcode

First name

Please add your first name

Mobile

Please enter a UK mobile or landline

Get my free quote

Free, no obligation, nobody visits your home. Prefer to talk? 07782 219224

Your design call is with Niall or Vince, our residential energy consultants.

Every export rate and the condition attached

Clearline 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, except the Octopus Flux and EDF SEG Export Variable rates, checked on 28 October 2026. Intelligent Octopus Flux is closed to new customers: Octopus lists it as temporarily unavailable and currently exclusive to customers who bought solar panels and a battery from Octopus. 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 published by region, so the figures above are ranges across regions. So Energy's own Smart Export Guarantee page no longer lists the 20p rate it offered for 12 months, so we do not treat it as available.

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. Our MCS-certified, fully insured installation teams carry out every installation, 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

1. 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.
2. Read the eligibility line on the export tariff before you commit to an import tariff, because that is where the exclusions live.
3. 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.
4. 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.
5. Treat supplier-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 Good Energy's 25p falls to 12p after 12 months.
6. 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.
7. Watch the January cap. The October to December 2026 cap is confirmed and current; EDF, British Gas and E.ON Next have forecast rises of 21.8% to 23.9% for the January to March 2027 cap (forecasts dated 21 to 23 September 2026), and Ofgem confirms the actual figure in late November. That reset moves the benchmark every fixed and time-of-use offer in this guide gets compared against.