Reviewed 9 September 2026. The best electricity tariff for solar panels and battery storage depends on when you import electricity, how much solar you export and whether you own an electric vehicle. A low overnight rate is useful, but it does not automatically produce the lowest annual bill.
This guide replaces our earlier list of example tariff prices. Use the supplier links below to check current rates for your postcode and the terms offered to you before switching.
Start with your electricity use, not the cheapest headline rate
Look at a full year of electricity bills or smart-meter data where possible. Separate the electricity you buy during the day from overnight use, and identify large loads such as EV charging or electric heating. If you have solar, record generation and measured exports separately. Electricity generated by your panels is not the same as electricity bought from the grid.
A household that already charges its car cheaply overnight has a different opportunity from one that buys most of its electricity at daytime prices. For the first household, battery savings depend mainly on the remaining higher-priced household demand, rather than the total annual usage including the car.
Compare the main tariff types
Standard fixed or variable tariffs
A tariff with one electricity unit rate is straightforward to compare and manage. A battery can still store spare solar generation for use later, but there is no day/night price difference to exploit unless the tariff provides separate time periods. Compare the standing charge as well as the unit rate, and check any exit fee.
EV tariffs with cheaper overnight electricity
An EV tariff may suit a household with a qualifying electric vehicle and suitable metering. Octopus Go, for example, currently describes an overnight period of 00:30–05:30 and requires an electric car charged at home and a compatible smart meter. The supplier provides a postcode rate checker. Its requirements should not be confused with those of other smart-charging products.
Check whether the offered tariff permits your planned battery charging, what rate applies to other household consumption, and which export tariff you can use alongside it. A battery-only home without an EV should not assume it qualifies for an EV tariff.
Half-hourly electricity tariffs
On a half-hourly tariff, the price varies through the day. Agile Octopus links half-hourly prices to wholesale electricity conditions. That can provide opportunities to shift demand, but it also exposes you to changing prices. You need to understand the tariff terms and how your equipment will respond.
A compatible controller can help schedule charging, but do not assume that every inverter supports every tariff automatically. Check the exact model, firmware and control arrangement. Set sensible limits so the system does not charge simply because a schedule is enabled when the price no longer makes sense.
Tariffs designed for solar and batteries
Some products coordinate import and export periods. Octopus Flux is an example designed around solar and battery use. Compare the import cost, export payment and time periods together; concentrating only on the export headline can hide the cost of buying electricity at other times.
Check the supplier’s current equipment and eligibility requirements. Products with similar names can use different control arrangements, so confirm who controls charging and export and whether that suits your household.
Account for battery losses and export income
A battery does not return every unit of electricity used to charge it. Your estimate should allow for charging and discharging losses, standby consumption, usable capacity and the amount of energy your home can actually use during the expensive period.
Illustrative calculation, not a tariff quote: if charging electricity costs 10p/kWh and the assumed round-trip efficiency is 90%, one delivered kWh costs about 11.1p in charging electricity. If that replaces a 30p/kWh purchase, the gross difference is about 18.9p per delivered kWh. This excludes installation cost, battery ageing, standby use, standing-charge changes and other running costs. Use your actual rates and a justified efficiency assumption.
Solar charging also has an opportunity cost if you would otherwise receive payment for exporting that electricity. Compare the value of using stored energy with the export income you give up. Feed-in Tariff generation payments, deemed export and metered export are different arrangements; check your own agreement rather than treating them as interchangeable.
Check import and export compatibility before switching
Do not assume that an import tariff can be paired with any export product. Supplier rules change. Octopus now states that its Outgoing and Agile Outgoing products can be combined with Octopus Go and Intelligent Octopus Go, whereas older advice described more restrictive combinations. Check the current supplier explanation and the terms offered for your account.
For any supplier, confirm the meter requirements, payment arrangements, contract dates and whether the installation needs particular certification. Keep a copy of the offer you accept.
Make sure the battery fits the cheap-rate window
Battery energy capacity is measured in kWh; charging power is measured in kW. A large battery paired with a modest charger may not refill during a short cheap-rate period, especially while the house and EV are drawing power. Your electrical supply and system limits also matter.
Size the system around the higher-priced electricity you can realistically replace, the overnight window and the equipment’s usable limits. Our guide to choosing a home battery size when you have an EV tariff explains the relationship in more detail.
A practical switching checklist
- Compare a full year of estimated imports and exports, not one favourable day.
- Check daytime rates, cheap-rate hours, standing charges and exit fees.
- Confirm EV, meter, equipment and export-product eligibility.
- Allow for battery losses, charging limits and realistic household demand.
- Check who controls the system and whether you can override its schedule.
- Review the result after the first complete billing period and across different seasons.
Discuss a system designed around your home
If you already have panels, explore adding battery storage to existing solar. If you do not have panels, see how battery storage without solar can work with an appropriate off-peak tariff.
Sunergy Renewables can assess your bills, existing equipment and installation requirements before recommending a system. Send us your enquiry for advice based on your property and electricity use.
