Solar battery tariffs decide how much of a customer's system pays for itself, and the spread is wide: on a typical 5kWp home with a battery, the gap between the worst and best export tariff is roughly £300 to £400 a year of pure income (EnergyPlus, 2026). For an installer, that number is a sales tool. It turns a battery from a comfort purchase into a return your customer can see on a bill.
This guide compares the main solar battery tariff types in 2026, from flat export rates to time of use tariffs built around a battery. It is written for installers who need to advise which tariff fits which system, not for a homeowner picking a supplier blind. Every rate here changes often, so treat the figures as a snapshot and confirm live rates before you quote.
Key Takeaways
- A solar battery tariff has two halves that matter: the export rate you sell surplus at, and the cheap import window you charge the battery in overnight.
- Fixed export rates in 2026 ran up to 25p/kWh on a supplier's own install, but independent installs are usually capped near 15p (EnergyPlus, 2026).
- Time of use tariffs like Octopus Flux can pay 25p to 30p/kWh in the peak window, but only a battery can shift export into that window (Cucumber Eco, 2026).
- An MCS certificate is a hard gate: without it the customer cannot register for the Smart Export Guarantee at all (MCS, 2026).
- The best solar battery tariff is the one that matches the customer's usage pattern, not the one with the biggest headline number.
What is a solar battery tariff?
A solar battery tariff is an energy contract designed so a home battery earns money on both sides of the meter, combining a cheap overnight import rate with a paid export rate for surplus solar. Every export rate sits under the Smart Export Guarantee, the government scheme that replaced the Feed-in Tariff export payment in 2020 (Sunsave, 2026).
The battery is what creates the value. Without storage, a home exports whenever the sun shines, which is often when export prices are lowest. A battery lets the system hold that energy and either use it in the evening or sell it during a paid peak window. This is why battery tariffs and plain solar export tariffs are not the same conversation, even when the export rate on paper looks identical.
The type of battery coupling also shapes how freely a system can time its exports. An AC coupled retrofit and a DC coupled new build behave differently when the tariff asks the battery to discharge into a narrow peak, and that affects which tariff you should recommend. Our guide to AC coupled battery storage explains the difference in plain terms for the handover conversation.
Fixed export tariffs versus time of use tariffs
Fixed export tariffs pay one flat rate for every unit exported, while time of use tariffs vary the rate by time of day, rewarding exports sent during the late-afternoon peak. In 2026 the best fixed rates reached 25p/kWh from Good Energy, with So Energy and OVO up to 20p and E.ON Next around 17.5p, though most of these apply only to the supplier's own installs and often last just 12 months (EnergyPlus, 2026).
A fixed rate suits a customer who wants simplicity and predictable income. A time of use tariff suits a customer with a battery and the willingness to let the system, or the supplier, time exports. The rule of thumb: no battery means a fixed rate almost always wins, because there is nothing to shift into a peak window.
Here is how the common 2026 options compare:
- Octopus Outgoing Fixed: flat 12p/kWh after the March 2026 cut, no battery required, simple and predictable (Sunsave, 2026).
- British Gas Export and Earn Plus: around 15.1p/kWh fixed, but requires bundling a British Gas import tariff (EnergyPlus, 2026).
- E.ON Next Export Exclusive: around 16.5p/kWh, also tied to an E.ON import tariff (EnergyPlus, 2026).
- Octopus Flux: time of use, peak export up to around 29p/kWh, needs solar plus battery (Heatable, 2026).
- Intelligent Octopus Flux: time of use with supplier-controlled export, peak up to around 32p/kWh, paused to new customers since spring 2026 (Sunsave, 2026).
How does the Octopus Flux tariff work?
The Octopus Flux tariff is a time of use tariff that pays its highest export rate in the 4pm to 7pm evening peak, when grid demand and wholesale prices are highest. For a battery household that can hold solar back and release it into that window, Flux can pay 25p to 30p/kWh at peak, several times the daytime rate (Cucumber Eco, 2026).
Flux works because it mirrors the wholesale market. Cheap overnight import lets the battery fill up, solar tops it up by day, and the peak export rate rewards selling in the early evening. The catch is that it needs solar, a battery and an Octopus import tariff together. A customer with panels but no battery gains little, because they have nothing stored to sell when the peak rate lands.
What is Intelligent Octopus Flux?
Intelligent Octopus Flux is the automated version of Flux, where the supplier controls the battery directly, charging it on cheap overnight and solar power and then selling the stored energy into the peak window for the customer. It has paid the highest headline export rate on the market, up to around 32p/kWh at peak (Heatable, 2026).
The trade is control. The homeowner hands scheduling to the algorithm in exchange for the best rate and no manual timer setting. One practical note from the field: this tariff has been closed to new customers since spring 2026, so do not build a sales pitch around it until it reopens (Sunsave, 2026). Quote the tariffs a customer can actually sign up to today.
Why the import rate matters as much as the export rate
The import side of a battery tariff is half the return, because a battery that fills on an 8p overnight rate and displaces a 25p daytime rate saves the difference on every stored unit. Tariffs like Intelligent Octopus Go offer an off-peak rate near 8p/kWh across a six-hour overnight window from 23:30 to 05:30 (SolarInfo, 2026).
Installers often anchor the whole conversation on export rates because they are the visible income line. In practice the cheap import window can be worth more, especially for a household with high evening use or an EV. When you size a battery, match it to both the solar surplus and the overnight window the customer will charge in. Our solar battery sizing guide walks through that method.
Which solar battery tariff is best for your customer?
The best solar battery tariff depends on the customer's roof, battery and daily rhythm, not on the top line rate, and there are 37 or more Smart Export Guarantee tariffs on the market in 2026 to choose between (Sunsave, 2026). A high daytime user with no battery wants a strong fixed export rate. A battery household that can shift load wants a time of use tariff with a fat peak window.
Three questions sort most customers. Does the home have a battery that can time exports, or only panels? Is the customer willing to bundle import and export with one supplier for a better rate? And when do they actually use power, morning, evening or overnight? Map those answers to the tariff table above and the choice usually makes itself. For homes weighing storage without panels, our guide to home battery storage without solar covers the tariff maths there too.
How do customers qualify for a solar battery tariff?
Customers qualify for a Smart Export Guarantee tariff through an MCS certified installation and a supplier that offers export payments, and every large supplier with 150,000 or more customers must offer at least a 1p/kWh SEG rate by law (MCS, 2026). Without an MCS certificate, there is no SEG registration and no export income at all.
Demand is climbing fast, which makes tariff advice a live part of the sale. MCS recorded 36,000 certified battery installations in the first half of 2026, almost double the same period a year earlier, and nearly all of them went onto homes that already had solar (MCS, 2026). Getting the export paperwork and tariff right at handover is now a standard part of a good install. For the export scheme rules themselves, see our Smart Export Guarantee rates guide.
Getting the tariff right at handover
Tariff choice belongs in the handover conversation, not as an afterthought weeks later. A customer who leaves an install on a 1p default export rate loses hundreds of pounds a year against a well-matched tariff, and they will remember who advised them when they notice. Walk them through the fixed versus time of use choice, confirm whether their battery can time exports, and point them at a live comparison before they commit.
Reonic's installer tools help you capture the system spec and export setup cleanly at handover so nothing gets lost between commissioning and the customer's first export payment. The tariff market shifts monthly, so build the habit of checking current rates at every quote rather than trusting a figure from last quarter. That single habit protects both your customer's return and your reputation. For retrofit jobs, our guide to adding battery storage to existing solar covers the DNO and tariff steps.
Frequently asked questions
What is the best solar battery tariff in 2026?
There is no single best solar battery tariff, because it depends on whether the home has a battery and when it uses power. Time of use tariffs like Octopus Flux pay the most at peak, up to around 30p/kWh, but only suit battery homes that can shift export into the evening window (Cucumber Eco, 2026).
Do you need a battery to get a good export tariff?
No, but a battery changes which tariff wins. Without storage, a flat fixed export rate almost always pays more than a time of use tariff, because there is nothing stored to sell during the paid peak window. A battery lets a home hold solar and release it when export rates are highest (EnergyPlus, 2026).
Why did Octopus cut its Outgoing export rate?
Octopus cut its flat Outgoing Fixed export rate from 15p to 12p from March 2026, bringing it in line with several other suppliers (Sunsave, 2026). Export rates track wholesale conditions and supplier strategy, so both cuts and rises happen across the market and figures should be checked live.
Can a customer switch export tariff without changing import supplier?
Sometimes, but many of the best rates require bundling import and export with one supplier. Tariffs like British Gas Export and Earn Plus and E.ON Next Export Exclusive only pay their headline rate if the customer also takes that supplier's import tariff (EnergyPlus, 2026). Standalone export switching is possible but usually pays less.
Is an MCS certificate required for a solar battery tariff?
Yes. An MCS certified installation is the gateway to the Smart Export Guarantee, and no supplier will register a system for export payments without it (MCS, 2026). This is why the certificate and the export registration should be completed as part of the handover, not left to the customer.
