Your tariff has two sides — and both matter
When you have solar panels, your electricity costs split into two separate flows: what you buy from the grid (import) and what you sell back to it (export). These can be with different suppliers, at different rates, and optimising both is how you get the best financial return from your system.
This is your standard electricity bill. Every kWh your home draws from the grid is charged at your import rate. Solar reduces this by powering your home directly during the day, and a battery extends that coverage into the evening. The less you import, the lower your bill — but the rate you pay for what you do import still matters.
When your panels generate more than your home and battery can use, the surplus flows to the grid. With an export tariff, you get paid for every kWh you send back. Without one, that energy is given away for free. Export rates range from 3p to 15p per kWh depending on your tariff and supplier.
Best tariff options if you have a battery
A battery changes everything about tariff selection. It lets you buy electricity when it is cheapest and use it when it is most expensive — effectively arbitraging the price difference. Time-of-use tariffs are designed for exactly this, and they almost always outperform flat-rate tariffs when a battery is involved.
Octopus Flux is purpose-built for solar and battery systems. It has three rate periods: cheap overnight (02:00–05:00, around 12p/kWh), standard daytime, and premium peak export (16:00–19:00, up to 25p/kWh). The strategy: charge the battery at 12p overnight, let solar top it up during the day, then export stored energy at 25p during the peak window.
Octopus Go offers a cheap overnight window (00:30–04:30, around 7p/kWh) with a standard daytime rate. Intelligent Octopus Go is similar but designed for EV owners with compatible chargers — it can extend the cheap window if your car needs more charge. Both work well for batteries: charge overnight at 7p and use stored energy during the day. The export rate is typically lower than Flux's peak export, so Go suits homes that self-consume most of their energy rather than export.
Agile has half-hourly pricing that changes daily based on wholesale costs. Prices can go negative (you get paid to use electricity) and can spike above 100p/kWh during peak demand. It rewards active management — charging the battery during cheap or negative periods and avoiding import during spikes. Agile works best with home automation platforms that can respond to price signals automatically. Without automation, managing Agile manually is time-consuming and risky if you miss a price spike.
Best tariff options without a battery
Without a battery, you cannot store cheap overnight electricity, so the main advantage of time-of-use tariffs disappears. Your strategy is simpler: keep your import rate low, maximise self-consumption during solar hours, and make sure you have a competitive export rate for the surplus.
Find the best flat-rate import deal you can, then pair it with the highest-paying Smart Export Guarantee rate available. This combination is simple, predictable, and requires no schedule configuration. You save the full import rate on every kWh you self-consume and earn the export rate on every kWh you send to the grid. No smart meter is strictly required for the import tariff, but you do need one for export payments.
Without a battery, you cannot take advantage of cheap overnight rates because you have nothing to store the energy in. However, if your household naturally uses a lot of electricity overnight (immersion heater on a timer, EV charging, storage heaters), a time-of-use tariff may still save money on that specific overnight usage. The solar benefit during the day is the same regardless of your import tariff type — it offsets whatever rate you would otherwise pay.
Tariff comparison at a glance
Approximate rates as of early 2026. All tariffs require a smart meter except standard flat-rate. Rates change — always check current pricing with the supplier before switching.
| Tariff | Cheap rate | Day rate | Export rate | Best for |
|---|---|---|---|---|
| Octopus Flux | ~12p | ~24p | ~25p peak | Solar + battery (export focused) |
| Octopus Go | ~7p | ~24p | ~15p | Battery + EV (self-consumption focused) |
| Octopus Agile | Variable | Variable | Variable | Tech-savvy owners with automation |
| Flat rate + SEG | — | ~24p | 4–15p | Solar only (no battery) |
Export tariffs — getting paid for your surplus
The Smart Export Guarantee (SEG) is the UK scheme that pays you for solar electricity exported to the grid. It replaced the old Feed-in Tariff for new installations. If you do not have an export tariff, every kWh you export earns nothing — this is surprisingly common and one of the easiest fixes for a new solar owner.
A fixed-rate SEG tariff pays the same price per kWh regardless of when you export. Rates range from 3p to 15p depending on the supplier. Higher rates sometimes come with conditions (minimum export volume, annual review). Fixed SEG is the safest option if you want predictable income from your exports with no management required.
Some suppliers offer variable export rates that track wholesale prices. When wholesale prices are high (winter evenings, calm days with low wind), export rates can spike well above fixed SEG rates. When wholesale is low, the rate drops. Agile Outgoing from Octopus is the best-known example. This works well if you have a battery and can time your exports to high-price periods.
Some time-of-use tariffs include export rates as part of the package. Octopus Flux includes a premium peak export rate (up to 25p) during the 16:00–19:00 window. This is often better than any standalone SEG rate, but it means your import and export are tied to the same supplier and tariff.
How to switch your tariff
Switching is straightforward, but there are a few things to check and configure after the switch to make sure your system takes full advantage of the new rates.
In the first week after your tariff switches, check your monitoring data daily. Confirm: battery is charging during the new cheap window, battery is discharging or exporting during peak hours (if applicable), your import and export figures look correct on your smart meter, and no error codes have appeared on your inverter.
When clocks change in March and October, some inverters adjust schedules automatically and some do not. If yours doesn't, your charge window shifts by an hour — potentially missing the cheap rate entirely. Check and adjust your schedule twice a year. Our Flux guide covers the fix for each brand.
Related guides
Self-consumption, battery scheduling, load shifting, and the common mistakes that cost new owners £200–£500 per year.
How SEG works, current rates, eligibility, and how to sign up with the best-paying supplier.
Full setup guide for Flux's three-period tariff, including brand-specific inverter configuration and BST fixes.
Battery chemistry, BMS, charge cycles, degradation — the technical foundation for understanding battery tariff strategies.
If you have solar but no battery, adding one unlocks time-of-use tariff savings and dramatically improves self-consumption.
What to check monthly, quarterly, and annually to keep your system performing at its best.