Octopus Battery Storage and Smart Tariffs
Octopus battery storage is not a product you buy from Octopus. It is a home battery paired with an Octopus smart tariff. The battery charges when power is cheap and sends it out when it pays. The tariff therefore decides what the battery is worth.
How a home battery earns its keep on a smart tariff
A battery does two jobs. It stores spare solar power for the evening, and it can also store cheap grid power for use later.
A smart time-of-use tariff makes the second job worth doing. The unit price changes by time of day, so a battery can buy low and use high. As a result, the tariff matters as much as the hardware.
Our guide to smart tariff optimisation covers how that pairing works in a home. Meanwhile, the page on home battery storage explains the equipment itself.
What Octopus tariffs exist for batteries
Octopus runs several smart tariffs, and the rates move often. Therefore we only quote the ones we checked in October 2026. Please treat them as examples, not offers.
Intelligent Octopus Go is a time-of-use tariff. In October 2026 its cheap rate was 7.6p per kWh from 23:30 to 05:30. Octopus also lists up to six hours a day of smart-charging off-peak time, although the timing varies.
The page we read describes eligibility in terms of an electric vehicle or a supported smart charger. It does not say a home battery qualifies. Ask Octopus whether your battery brand is supported before you assume it.
On the export side, Octopus lists a Smart Export Guarantee tariff. Its open version paid a flat 4.1p per kWh in October 2026, and you did not need to move your import supply. However, Octopus also listed 12p per kWh for customers who import with Octopus too.
Import tariffs and export tariffs are two different things
People often mix up the two sides. An import tariff sets what you pay for power from the grid. An export tariff sets what you are paid for power you send back.
You can usually pick them separately, although some suppliers pay more to their own import customers. For example, Octopus lists one export rate for all and a higher one for its own customers. In contrast, British Gas listed 3p per kWh for non-customers in October 2026.
| Tariff type | What it sets | Where a battery helps |
|---|---|---|
| Time-of-use import | Price per kWh by time of day | Charges when power is cheap |
| Flat export (SEG) | Payment per kWh you send out | Lets you pick when to export |
| Bundled import and export | Both rates from one supplier | Can raise the export rate |
Our guide to the Smart Export Guarantee with a battery explains the rules in more detail. It also covers the MCS requirement, which matters because it decides who can claim.
The arithmetic behind the gain
The gain from a battery on a time-of-use tariff comes from the gap between two prices. You multiply that gap by the kWh you move each day. Then you multiply by 365 for a yearly figure.
Here is an illustration, using the figures above. From 1 October to 31 December 2026 the Ofgem price cap averages about 26p per kWh for electricity. A cheap rate of 7.6p therefore leaves a gap of about 18p per kWh.
If you moved 5 kWh a day, that would be about 92p a day. Treat this as a method, not a forecast. Your peak rate, your usage and the battery’s round-trip losses will all change the result.
For the bigger picture, see our guide on whether solar batteries are worth it. It weighs the gain against the cost of the battery.
Panels, a battery and a cheap rate together
If you have solar panels, the battery has a third job. It soaks up midday solar power that you would otherwise export at a low rate. Evening demand then draws on that stored power.
How much solar you have to store depends on where you live. The EU PVGIS tool estimates that a 4 kWp array in Brighton makes about 4,624 kWh a year. In contrast, the same array in Manchester makes about 3,544 kWh.
That gap matters because more solar means more spare power to store. Homeowners looking at battery installers serving Brighton may find the battery fills on more days. In Manchester the cheap overnight rate may do more of the work. Solar battery quotes in Manchester are worth comparing on that basis.
London and Southampton sit between those two. A 4 kWp array makes about 4,075 kWh in central London and 4,255 kWh in Southampton. You can read more about solar and battery options in London and Southampton battery storage on our city pages.
Adding a battery to a system you already own
Many homes already have panels. If that is you, you can often add a battery later. However, the details depend on your inverter and its wiring.
Because of this, ask whether the battery connects on the DC side or the AC side. Ask too whether your existing export meter still works. Our guide on how to add a battery to existing solar walks through the options.
Charging an electric car from the same tariff
Some smart tariffs are built around electric vehicles. Home chargepoints sold in Great Britain since mid-2022 must be smart, with off-peak charging set by default. That makes them a natural fit for a time-of-use tariff.
A battery and an EV can share the same cheap window. However, the two compete for the same hours, so the charger and battery need to be set up together. Our guide to charging an EV with solar covers the practical side.
Questions to ask before you pick a tariff
Rates are the easy part to compare, while the terms are harder. Ask the following before you sign.
- Does the tariff work with my battery brand and my inverter?
- Do I need to buy my electricity from the same supplier to get the best export rate?
- Is a smart meter or half-hourly export meter already in place?
- What happens to the rate if the supplier changes it?
- Are there exit fees if I want to leave?
Price is the other side of the choice. Our guide to what a solar battery costs in the UK explains how to read a quote. Furthermore, home batteries are currently VAT-free (0%) until 31 March 2027.
What a tariff cannot do
A cheap rate does not fix a battery that is too small or too large. An oversized battery never fills with solar power, so the extra capacity sits idle. If it is too small, it runs out before the evening peak ends.
Similarly, a tariff cannot guarantee a payback time. Rates change each quarter, and the Ofgem cap is reset every three months. Therefore a sensible plan still works if the gap between cheap and peak rates narrows.
Ask your installer to show the battery working at today’s rates and at lower ones. A quote that only works at the best case is a warning sign.
Why MCS matters for the export side
To claim Smart Export Guarantee payments, your system must be MCS-certified. You also need a smart meter or another half-hourly export meter. Without MCS, you may not be able to claim at all.
MCS installers work to published standards, including MIS 3002 for solar panels and MIS 3012 for home batteries. A good installer also follows PAS 63100 when deciding where the battery goes. Specifically, ask them to explain the siting choice for your home.
Solar Base Energy is a free matching service. We match you with an MCS-certified installer through our quote form, and we do not install anything ourselves. Tell us you want a battery for a smart tariff. The installer can then advise on the options that suit your home.
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Frequently asked questions
Does Octopus have a tariff for home batteries? +
Octopus offers smart time-of-use tariffs and an export tariff that suit a home battery. Whether your battery works with a given tariff depends on the brand and the tariff rules, so check the supplier's page before you buy.
Do I need to switch my electricity supply to get paid for exports? +
Not always. In October 2026 Octopus listed an open export tariff that does not require you to switch your import supply. However, a higher rate was listed for customers who also buy their electricity from Octopus.
Do I need an MCS installer to claim export payments? +
Yes, your system must be MCS-certified to claim Smart Export Guarantee payments. You also need a smart meter or another half-hourly export meter.
Can a battery make a cheap overnight rate worth more? +
It can, because a battery can fill up while power is cheap and release it when power costs more. The gain depends on the size of the gap between the two rates, so work it out with your own figures.